RU2461932C2 - Semiconductor disc laser - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: laser has an active plane with a mirror coating on the first surface which is attached to a first cold-conducting substrate, an external feedback mirror and a pumping laser. The active plate lies between the mirror coating and the external feedback mirror, which are elements of the optical resonator of the disc laser. The pumping laser has its own stable optical resonator and the wavelength of its radiation is shorter than that of the disc laser. The active plate of the disc laser is one of the reflecting elements of the stable optical resonator of the pumping laser, wherein during reflection of radiation generated in the pumping laser from the active plate, part of the radiation is partially absorbed in the active plate, thereby exciting the disc laser.

EFFECT: high power of radiation and wider spectral range.

23 cl, 9 dwg

Description

The invention relates to quantum electronics and electronic equipment and can be used in devices with a powerful collimated light beam, in particular in television projectors, laser locators, medicine, photolithography.

Known semiconductor disk laser containing an electron gun forming an electron beam, a semiconductor wafer with a highly reflective mirror coating and an external translucent feedback mirror (O.V. Bogdankevich, S. A. Darznek, P. G. Eliseev. Semiconductor lasers. M: Science, 1976, p. 256).

In this device, an electron beam penetrates into a semiconductor wafer made of a single crystal through a highly reflective coating and excites a single crystal wafer, luminescence and optical amplification occur in it. A highly reflective mirror coating and an external feedback mirror form an optical resonator. The generated laser radiation leaves the resonator through an external translucent mirror. The depth of excitation of the plate is much smaller than the diameter of the electron beam. Therefore, the active region is a disk. The radiation wavelength depends on the choice of material of the semiconductor wafer and can correspond to the near infrared, visible and near ultraviolet ranges.

The disadvantage of this device is that the threshold for generating laser radiation is too high at room temperature and the laser operates only in a pulsed mode.

A laser cathode ray tube is known that contains in an evacuated flask with an output optical window an electron beam source, means for controlling it and an active target made in the form of a single-crystal plate with two mirror coatings: highly reflective from the side of the incident electron beam and translucent from the side of the plate mount on a cold-conductive substrate (V.I. Kozlovsky, A.S. Nasibov, Yu.M. Popov, P.V. Reznikov. Continuous electron-pumped laser. Letters in ZhTF. 1980, V.7, N.8, p. 463).

The plate is made of single crystals of GaAs, InP or GaSb having a high coefficient of thermal conductivity. The cavity length is equal to the plate thickness and does not exceed 100 μm. The laser can operate in continuous mode with a stationary electron beam.

The disadvantage of this device is that continuous operation is achieved only at cryogenic temperatures. Generation is achieved only at individual wavelengths in the infrared range, determined by the material used. Power is limited to a few tens of milliwatts. In addition, the divergence of the laser beam is not high enough and amounts to several angular degrees.

A laser cathode ray tube is known that contains in an evacuated flask with an output optical window an electron beam source, means for controlling it and an active target made in the form of a heterostructure with two mirror coatings: highly reflective from the side of the incidence of the electron beam and translucent from the side of the plate mounting on cold conductive substrate (Kozlovsky VI, Lavrushin BM Laser cathode ray tube. RF patent No. 2056665).

The use of a heterostructure with strained quantum wells makes it possible to significantly lower the generation threshold at room temperature and to expand the range of materials that can be used, which ultimately allows efficient generation in the visible and ultraviolet regions of the spectrum with a power of several watts.

However, in this device, it is still not possible to improve radiation directivity. The angle of divergence of the radiation exceeds 10 degrees, which is determined by the small (4-5 μm) cavity length. In addition, at room temperature, the laser operates only in pulsed or scanning mode.

Closest to the claimed technical solution is a semiconductor disk laser containing an active plate with a mirror coating mounted on a cold-conductive substrate, an external feedback mirror and a pump laser, the active plate being between the mirror coating and the external feedback mirror, which are elements of a disk optical resonator laser, and the pump laser radiation wavelength is shorter than the disk laser radiation wavelength (Caprara Andrea, Chilla Juan L., Spinelli Luis A., High-power external-cavity opticall y-pumped semiconductor laser, US Patent 6,285,702 September 4, 2001; J. Chilla, St. Butterworth, A. Zeitschel, J. Charles, A. Carpara, M. Reed, L, Spinelli High power optically pumped semiconductor lasers, Proc / of SPIE, Vol. 5332, P143-150 (2004).)

The external feedback mirror is concave. Through it, the radiation is removed from the resonator. As the pump laser, laser diodes are used, the radiation of which is directed and focused on the surface of the active plate using additional optical elements. The plate is made of a heterostructure with many quantum wells. The absorption of pump radiation is mainly carried out by thick barrier layers separating quantum wells. Nonequilibrium carriers generated by absorption during their lifetime are collected in quantum wells, where radiative recombination occurs. The quantum wells are placed in the antinodes of the resonator mode, which provides approximately twice as much optical gain in the direction of the optical axis of the resonator as in the transverse direction. Heterostructures are made of compounds A3B5, emitting in the infrared region of the spectrum. The radiation divergence is close to the diffraction limit. The laser is in continuous mode. The radiation power reaches several watts. When a nonlinear crystal is placed inside the resonator, second harmonic generation with a radiation wavelength in the visible range can be achieved. In one embodiment of the device described above, a GaInP / AlGaInP heterostructure emitting at a wavelength of 676 nm was used (Jennifer E. Hastie, _ Lynne G. Morton, Alan J. Kemp, Martin D. Dawson, Andrey B. Krysa, John S. Roberts. Tunable ultraviolet output from an intracavity frequency-doubled red vertical-external-cavity surface-emitting laser. Appl. Phys. Letters 2006, Vol. 89, P.061114). A neodymium laser operating at the second harmonic with a radiation wavelength of 532 nm was used as a pump laser. When using a nonlinear crystal inside the cavity of a GaInP / AlGaInP heterostructure laser, lasing was achieved at a wavelength of 338 nm with a power of up to 0.12 W.

The disadvantage of this device is that at the main frequency, generation is achieved only in the infrared and red regions of the spectrum. Advancing into the green and blue regions using the second harmonic is associated with a loss in overall laser efficiency. It has not yet been possible to advance into the ultraviolet region of the spectrum shorter than 300 nm by using higher harmonics. Another disadvantage is the strong dependence of the generation power on the heat sink efficiency. The heat sink efficiency actually determines the output power of the laser.

The problem solved by the invention is to increase the power of a semiconductor disk laser by reducing the heating of the active heterostructure. Another objective is to expand the spectral range of semiconductor disk lasers.

The problem is solved in a semiconductor disk laser containing an active plate with a mirror coating on the first surface, mounted on a cold-conducting substrate; an external feedback mirror and a pump laser, which has a stable optical resonator, and its radiation wavelength is shorter than the disk laser radiation wavelength; moreover, the active plate is located between the mirror coating and the external feedback mirror - the elements of the optical resonator of the disk laser and at the same time is one of the reflective elements of a stable optical resonator of the pump laser, in which, when the generated radiation is reflected from the active plate, part of the radiation is partially absorbed in the active plate, thereby exciting disk laser.

The essence of the invention lies in the fact that the use of an active plate of a disk laser as one of the elements of the optical cavity of the pump laser significantly expands the ranges of variation of the main parameters of the disk laser. In particular, it is possible to reduce the heating of the active plate and increase the lasing power by using pump radiation with a wavelength only slightly shorter than the wavelength of the generated radiation in a disk laser. Indeed, in the known technical solutions, the active plate is made of a semiconductor heterostructure with quantum wells having a smaller band gap than the band gap of the barrier layers separating the layers of the quantum wells. Pump radiation is absorbed in thick barrier layers. To achieve a low lasing threshold at room temperature, the band gap of the barrier layers should exceed the band gap of quantum wells by about 300 meV. Each pair of nonequilibrium carriers, falling into quantum wells, gives most of these 300 meV to the crystal lattice, heating it. The use of pump radiation, which would be absorbed only in quantum wells, is impossible in the known technical solutions due to too weak absorption at the thickness of the heterostructure. It is required to organize many passages of pump radiation through the active plate. This is achieved in the claimed technical solution. In this case, the heating can be reduced by ten times. For this, the quantum energy of the pump radiation should be only 30 meV greater than the quantum energy of the radiation generated in the disk laser.

This invention also allows to simplify the optical scheme of incoherent summation of radiation of multi-element pump lasers. An example of such a laser is an array of laser diodes with an external resonator. This can be a matrix of laser diodes with a lateral output of radiation or a matrix of laser surface-emitting chips with longitudinal injection (the so-called lasers with a vertical resonator in the English literature).

Another example of a multi-element laser is a laser cathode ray tube with an external resonator (V. I. Kozlovsky, B. M. Lavrushin, Ya. K. Skasyrsky, M. D. Tiberi. Laser with an external resonator operating at a wavelength of 625 nm at optical pumping of an InGaP / AlGaInP nanostructure with a Bragg mirror. Quantum Electronics, 2009, 39 (8), pp. 731-734). The present invention provides various uses of a laser cathode ray tube as a pump laser of a semiconductor disk laser. The use of a laser cathode ray tube as a pump laser can significantly expand the spectral range of semiconductor disk lasers. Indeed, currently effective laser lasers include laser diodes that emit in the range of 750-980 nm. These diodes can pump disk lasers operating only in the infrared region of the spectrum. Another well-known pump laser, the efficiency of which is quite high, is a neodymium diode-pumped laser operating at the second harmonic. This laser can pump a disk laser operating in the red region of the spectrum. However, at present, there are no efficient pump sources for disk lasers operating at the fundamental frequency in the blue-green region of the spectrum. In the future, laser diodes based on GaN heterostructures and their solid solutions can become such lasers. Nevertheless, electron-pumped lasers are more promising for obtaining any generation wavelength in the visible and near ultraviolet spectral regions. In addition, they can be significantly cheaper when reaching the power level watt.

Various optical excitation schemes for the active plate of a disk laser are possible. In one design, the pump laser and the external feedback mirror of the disk laser are located on one side of the active plate. Then the active plate faces the first cold-conducting substrate with its first side with a mirror coating, which is made highly reflective at the wavelength of radiation of the disk laser and the wavelength of the radiation of the pump laser, and an additional coating is deposited on the second surface of the active plate, which is highly transmittance at the wavelength of radiation of the disk laser and transmits at least partially at the wavelength of the pump laser.

In this embodiment, the first cold conductive substrate may be opaque and made of a material with high thermal conductivity. It is desirable to make it from copper or copper alloys with other metals, for example with tungsten. Alloys are preferred if the process of fixing the plate to the first cold-conductive substrate occurs at elevated temperature and in order to avoid damage to the plate, it is necessary to coordinate the coefficients of thermal expansion of the substrate and the plate. The plate can be fixed by using optical adhesives (for example, EPOTEC-301), including opaque heat-conducting with metal filling (EPOTEC-H20E), or through metal solders with a relatively low softening temperature. These technologies are well known in the semiconductor industry.

The mirror coating on the first side of the active plate can be made of oxides with low and high refractive indices widely used in the optical industry. For the visible region, such known pairs as SiO2-TiO2, SiO2-ZrO2, Al2O3-Ta2O5 and others can be. For the ultraviolet region, a pair of SiO2-HfO2 is a preferred pair. To obtain high reflection simultaneously at the wavelengths of the generation of the disk laser and the pump laser, it is desirable to use a combination of interference dielectric coating and a metal layer of Al or Ag. The reflection coefficient at the wavelength of the generation of the disk laser is preferably done above 0.99. If it is lower than this value, then the losses on this mirror will be noticeable in comparison with other losses in the cavity, which will lead to an increase in the generation threshold and to a deterioration of other parameters of the disk laser. For the same reason, the additional coating on the second side of the active plate must have a transmission at a wavelength of radiation of the disk laser above 0.99. It can also be made of oxides in a known manner.

The active plate of a disk laser can be made of a single crystal of a semiconductor compound A2B6 or A3B5 with a band gap required to achieve a given generation wavelength. However, the threshold for generating such a laser at room temperature is too high. Therefore, it is advisable to perform the active plate in the form of a multilayer quantum-dimensional heterostructure made of compounds A2B6 or A3B5 with different bandgaps. A quantum-dimensional heterostructure can be a periodic structure with thin active layers of quantum wells, quantum wires, or quantum dots separated by thick barrier layers with a wider band gap. The heterostructure and mirror coating are made in such a way that the thin active layers are in antinodes of the optical mode of the disk laser resonator located at the maximum of the optical gain line. The heterostructure is grown by known methods of modern epitaxy, it has a thickness of 0.5 to 5 μm, and can be separated from the growth substrate and transferred to the first cold-conducting substrate. In one embodiment, the mirror coating is an epitaxial Bragg mirror grown in a single technological cycle with other layers of the heterostructure.

The reflection coefficient of the mirror coating on the first side of the active plate at the wavelength of the pump laser radiation can vary over wider limits. In the embodiment with an active plate in the form of a multilayer quantum well heterostructure, when the pump laser radiation is absorbed only in quantum wells, that is, the pump laser radiation wavelength is only slightly shorter than the disk laser generation wavelength, this reflection coefficient should also be higher than 0.99 so that the losses on this mirror were insignificant in comparison with other losses in the stable optical cavity of the pump laser. In this case, the transmittance of the additional coating at the wavelength of the pump laser radiation is desirable to make sufficiently high, not less than 0.9. If this coefficient is less than 0.9, then the pumping efficiency of the active element will not be high enough.

In the embodiment in which the active plate in the form of a multilayer heterostructure with quantum wells is pumped by radiation absorbed by thick barrier layers, the additional coating on the second side of the active plate should have a low transmittance, in the range of 0.01-0.1 and, accordingly, a high reflection coefficient (loss in this coating must be less than 0.01). If this transmittance is too low, the pump laser pump efficiency will be less than necessary to achieve the generation threshold, and if it is greater than 0.1, the generation threshold in the pump laser will increase due to too high losses of the stable absorption cavity in the active plate of the disk laser. In this case, the reflection coefficient of the mirror coating on the first side of the active plate can vary widely depending on the total thickness of the heterostructure, but it is desirable to make it greater than 0.9. If this reflection coefficient is less than 0.9, then the pumping of the active plate will be inhomogeneous, which will ultimately lead to a deterioration of the characteristics of the disk laser.

In another optical design, the pump laser and the external feedback mirror of the disk laser are located on opposite sides of the active plate. Then the active plate faces the first cold-conducting substrate with its second side, which is coated with an additional dichroic mirror coating, highly transmitting disk laser radiation and highly reflective pump laser radiation, and the mirror coating on the first side of the active region is highly reflective at the disk laser radiation wavelength and transmitting at least partially at the pump laser radiation wavelength.

In this embodiment, the first cold conductive substrate should be transparent and made of a material with high thermal conductivity. It can be made of sapphire, beryllium oxide, aluminum nitride, diamond or other transparent material. It is advisable to choose a material with a consistent coefficient of thermal expansion. The plate can be fixed by using transparent optical adhesives (for example, EPOTEC-301).

The mirror coating on the first side of the active plate can be made of oxides with small and large refractive indices SiO2-TiO2, SiO2-ZrO2, Al2O3-Ta2O5, SiO2-HfO2 and others. The reflection coefficient at the wavelength of the generation of the disk laser is preferably done above 0.99. If it is lower than this value, then the losses on this mirror will be noticeable in comparison with other losses in the cavity, which will lead to an increase in the generation threshold and to a deterioration of other parameters of the disk laser. For the same reason, the additional coating on the second side of the active plate must have a transmission at a wavelength of radiation of the disk laser above 0.99. It can also be made of oxides in a known manner.

The transmittance of the mirror coating on the first side of the active plate at the wavelength of the pump laser radiation can vary over wider limits. In the embodiment with an active plate in the form of a multilayer heterostructure with quantum wells, when the radiation of the pump laser is absorbed only in quantum wells, this transmittance should be higher than 0.9. If this coefficient is less than 0.9, then the pumping efficiency of the active element will not be high enough. In this case, the reflection coefficient of the additional coating at the wavelength of the pump laser should be higher than 0.99, otherwise the losses in the stable optical cavity of the pump laser will increase.

In the embodiment in which the active plate in the form of a multilayer heterostructure with quantum wells is pumped by radiation absorbed by thick barrier layers, the mirror coating on the first side of the active plate should have a low transmittance at the pump laser radiation wavelength, in the range of 0.01-0.1 and, accordingly, a high coefficient reflection (losses in this coating should be less than 0.01). If this transmittance is too low, the pump laser pump efficiency will be less than necessary to achieve the generation threshold, and if it is greater than 0.1, the generation threshold in the pump laser will increase due to too high losses of the stable absorption cavity in the active plate of the disk laser. In this case, the reflection coefficient of the additional coating at the pump laser radiation wavelength can vary widely depending on the total thickness of the heterostructure, but it is desirable to make it greater than 0.9. If this reflection coefficient is less than 0.9, then the pumping of the active plate will be inhomogeneous, which will ultimately lead to a deterioration of the characteristics of the disk laser.

In an embodiment in which the pump laser contains an array of active elements, the stable optical resonator has an optical axis along which a first feedback mirror, an array of active elements, a first lens with antireflection coatings, an active plate of a disk laser, a second lens with antireflection coatings are arranged in series and the second common feedback mirror, and the point of intersection of the optical axis with the first surface of the active plate refracting the optical axis is located near the rear focal the first plane of the first lens and near the front focal plane of the second lens.

The reflection coefficient of the first and second feedback mirrors should be above 0.99 in order to exclude additional losses in a stable resonator. In the above embodiment, these mirrors may be flat. They are made of known materials by known methods. Lenses also have known anti-reflective coatings. The transmittance of these coatings at a pump laser radiation wavelength should be higher than 0.99. Otherwise, the losses of the stable resonator increase. Lenses may have spherical surfaces if the dimensions of the lens are large compared to the transverse dimensions of the matrix of active elements. In this case, the spherical aberration of the lenses is quite low and they do not introduce additional losses into the stable resonator. If the transverse dimensions of the matrix of active elements are comparable with the sizes of the lens, then the surface of the lens must be made in the form of a paraboloid of rotation, which reduces their spherical aberration. Both lenses in this embodiment form a telescope, that is, the back (if the radiation propagates from the side of the matrix of active elements) the focal plane of the first lens coincides with the front focal plane of the second lens. The lenses are located symmetrically relative to the optical axis of the optical resonator of the disk laser. In this case, the optical axis of the stable optical resonator of the pump laser is refracted on the surface of the active plate, and the refraction point is located on the optical axis of the optical resonator of the disk laser. The accuracy of the location of the active plate relative to the lenses is within a few microns. The main requirement for the accuracy of the placement of the remaining elements is such that the optical cavity of the pump laser is stable. (Therefore, it is so designated.) The concept of stability of an optical resonator in optics is well known.

As a matrix of active elements, known matrixes of injection lasers with radiation output through cleaved surfaces can be used. In this case, the cleaved surfaces are clarified, and each element operates as a separate independent laser with an external resonator. A feature of the proposed scheme is that the generated spatial radiation modes of each individual independent laser intersect on the surface of the active plate of a disk laser, exciting it. The matrix of active elements may be a matrix of surface-emitting injection microlasers. Each microlaser operates with an external resonator.

In another embodiment, the pump laser instead of the matrix of active elements and the first feedback mirror contains a laser cathode ray tube with an electron-optical axis, containing in an evacuated flask with an output optical window, an electron source, an electrode system for forming an electron beam, a second active plate with a highly reflective mirror coating on its first surface, mounted on a second cold-conducting substrate, and Istemi focusing and deflecting the electron beam is placed a vacuum flask.

Instead of the second feedback mirror, you can use the second of the same laser cathode ray tube. Then the optical scheme will be symmetrical about the optical axis of the optical resonator of the disk laser. But in this case, it is necessary to provide optical coupling of the excitation region of the second active plate of the first laser cathode ray tube with the excitation region of the second active plate of the second laser cathode ray tube. This is done by known electrotechnical methods for controlling the position of the electron beam on the surface of the second active plate in each laser cathode ray tube.

To simplify the device, the first and second laser cathode ray tubes can be placed in a single evacuated flask with a single exit window. In this case, the second active plate of the first laser cathode ray tube and the second active plate of the second laser cathode ray tube will be a single second active plate fixed to a single second cold conducting substrate, and the first and second lenses will be combined in a single lens with antireflection coatings.

In another embodiment, you can leave only one laser cathode ray tube, as in the embodiment described above, then place the second feedback mirror in an evacuated flask next to the second active plate on one second cold-conducting substrate and leave one lens. You can do this as follows. The second active plate with a highly reflective mirror coating on the first surface is fixed on the first half of the second cold conductive substrate, in which the second half has a similar highly reflective mirror coating. A stable optical resonator has an optical axis along which a second cold-conducting substrate with a second active plate and a highly reflective mirror coating is sequentially placed on and off the first surface of the second active plate, an antireflection lens and an active disk laser plate, the first surface of which is located near the rear focal plane lenses. The spraying area of the highly reflective mirror coating on the first surface of the second active plate has a mirror symmetric spraying area of the highly reflecting mirror coating on the second half of the cold-conducting substrate relative to the optical axis of the stable optical resonator. The electron beam deflection system provides the location of the excitation region of the second active plate within the region with a highly reflective mirror coating on its first surface.

In all schemes using laser cathode ray tubes, several embodiments of the second active plate with a mirror coating and its fastening on the second cold-conducting substrate are possible, associated with different radiation output from the evacuated bulb. In one of these options, the second cold conducting substrate is transparent, the second active plate is fixed to the second cold conducting substrate by its second side, the output optical window is located between the second active plate and the first lens, and the second active plate is excited through a highly reflective mirror coating deposited on its first surface. Both surfaces of the exit window are brightened.

In this case, the first cold conducting substrate may be made of sapphire, beryllium oxide, aluminum nitride, diamond or other transparent material. It is desirable to select a material with a consistent coefficient of thermal expansion relative to the second active plate. The plate can be fixed by using transparent optical adhesives (for example, EPOTEC-301). The second surface of the second cold conducting surface is cleared at the wavelength of the radiation of the pump laser.

The highly reflective mirror coating on the first side of the active plate can be made of oxides with low and high refractive indices SiO2-TiO2, SiO2-ZrO2, Al2O3-Ta2O5, SiO2-HfO2 and others. To increase the reflection coefficient and remove excess charge from the surface of the second active plate introduced by the electron beam, it is desirable to deposit an Al, Ag, or other metal layer 0.02-1 μm thick over the oxides. The reflection coefficient of the mirror along the pump laser radiation length should be higher than 0.99 so that the losses on this mirror are much smaller than other losses in the stable cavity of the disk laser. The composition of the mirror and the thickness of the layers is optimized by known methods in order to reduce the energy loss of the electron beam when it penetrates into the second active plate through a highly reflective mirror.

Both surfaces of the exit window are brightened. But in one embodiment, the second cold conducting substrate is simultaneously the output optical window of the evacuated flask. It is also possible that the second cold conductive substrate has a flat and convex surface and is both the exit window of the evacuated flask and the first lens.

Radiation can also be removed from the second active plate through the surface excited by the electron beam. In this case, the second active plate is fixed on the second cold-conducting substrate with its first side, the output optical window is located between the second active plate and the active plate of the disk laser and has antireflection coatings, and the second active plate is excited through its second surface.

In this embodiment, it is possible to achieve a more efficient heat removal from the second active plate due to the fact that the second cold conducting substrate can be opaque and made of a material with high thermal conductivity. It is desirable to make it from copper or copper alloys with other metals, for example with tungsten. Alloys are preferred if the process of fixing the plate to the second cold conducting substrate occurs at an elevated temperature and in order to avoid damage to the plate, it is necessary to coordinate the coefficients of thermal expansion of the substrate and the plate. The plate can be fixed by using optical adhesives (for example, EPOTEC-301), including opaque heat-conducting with metal filling (EPOTEC-H20E), or through metal solders with a relatively low softening temperature. These technologies are well known in the semiconductor industry.

The highly reflective coating can be the same as in the case of radiation output through the second cold-conducting substrate, and the transmittance of the antireflection coating should exceed 0.99 in order to avoid additional losses in the stable cavity.

The second active plate can be made of a single crystal of an A2B6 or A3B5 semiconductor compound with a band gap required to achieve a given generation wavelength. However, the threshold for generating such a laser at room temperature is too high. Therefore, it is advisable to perform the active plate in the form of a multilayer quantum-dimensional heterostructure made of compounds A2B6 or A3B5 with different bandgaps. As in the case of the active disk of a disk laser, a quantum-dimensional heterostructure can be a periodic structure with thin active layers of quantum wells, quantum wires or quantum dots separated by thick barrier layers with a wider band gap. The heterostructure and mirror coating are made in such a way that the thin active layers are in the antinodes of the mode of a stable optical pump laser resonator located at the maximum of the optical gain line. The heterostructure is grown by known methods of modern epitaxy, it has a thickness of 0.5 to 10 μm, and can be separated from the growth substrate and transferred to a second cold conducting substrate. In one embodiment, the mirror coating is an epitaxial Bragg mirror grown in a single technological cycle with other layers of the heterostructure.

In one embodiment, the output optical window of the evacuated bulb is simultaneously the first lens.

The options described above have a relatively large length of a stable pump laser cavity. Therefore, they will work efficiently if each element of the matrix of active elements or a single pixel of the laser cathode ray tube will operate in continuous mode or in pulsed mode with a pulse duration significantly exceeding the round-trip time of a stable optical resonator. With a decrease in the pumping time of a single pixel in a laser cathode ray tube, which is desirable for improving heat removal, it is necessary to reduce the length of the stable resonator. From this point of view, the most promising embodiment of a disk laser is a laser that contains a laser cathode ray tube made in the form of a vacuum tube with an output optical window and having an electron optical axis along which an electron source is arranged in series, an electrode system for generating an electron beam and a second active plate with a highly reflective coating on its first surface, mounted on the first cold conducting substrate, as well as focusing systems and deviations of the electron beam placed outside the tube; moreover, the active plate of the disk laser is fixed in the Central part of the first cold-conducting substrate with its first surface with a mirror coating, which is made highly reflective for the wavelength of the radiation of the pump laser and the radiation wavelength of the disk laser; on the one side of this plate, the second active plate is fixed with its first surface with a highly reflective mirror coating at the wavelength of the pump laser radiation, and on the other hand a highly reflective coating is sprayed, similar to the coating deposited on the first surface of the second active plate; an antireflection coating is applied to the second surface of the second active plate, through which the electron beam excites the second active plate; on the second surface of the active disk of the disk laser, a coating is applied that is highly transparent at the wavelength of the radiation of the disk laser and passes at least partially at the wavelength of the radiation of the pump laser, through which optical pumping of the disk laser is performed; the external feedback mirror of the disk laser is made in the form of an exit window of a vacuum flask, in which the surface facing the second surface of the active plate of the disk laser is concave and coated with a mirror coating, highly reflective for the pump laser radiation wavelength and partially transmitting at the wavelength radiation from a disk laser, at least in the central part of the output window; the first surfaces of the active plate of the disk laser and the second active plate, as well as the outer surface of the highly reflective mirror coating deposited on a part of the surface of the first cold conducting substrate, are located near the focal plane of the external mirror; the optical resonator of the disk laser and the stable optical resonator of the pump laser have a single optical axis that passes through the central part of the first cold-conducting substrate, coinciding with its normal; the surface of the second active plate has an axisymmetric region with a highly reflective mirror coating on the surface of the first cold conducting substrate outside the plate; the shape of the concave surface is close to the paraboloid of rotation around the optical axis.

In this embodiment, the first refrigerant substrate replaces the functions of the second refrigerant substrate. The radiation generated in the stable optical cavity of the pump laser, at any position of the electron beam on the second active plate, leaves this plate perpendicular to its surface, is reflected from the external concave mirror, then is reflected from the active plate of the disk laser, partially rinsed in it, is reflected a second time from external mirror, heading towards a highly reflective mirror coating located on the surface of the first cold-conducting substrate axisymmetrically to the second active plate, reflect aetsya from this coating and returns to the second plate along the return path.

The invention is illustrated by the following figures.

Figure 1. Semiconductor disk laser, which is the closest technical solution to the claimed device.

Figure 2. Semiconductor disk laser according to the claimed technical solution.

Figure 3. Other versions of the active plate of a semiconductor disk laser according to the claimed technical solution.

Figure 4. A semiconductor disk laser in which a pump laser contains an array of active elements.

Figure 5. A semiconductor disk laser, in which the pump laser contains a laser cathode ray tube.

6. A semiconductor disk laser, in which the pump laser contains a laser cathode ray tube, made in another embodiment.

7. A semiconductor disk laser, in which the pump laser contains two laser cathode ray tubes in a single vacuum flask.

Fig. 8. A semiconductor disk laser with two external feedback mirrors, in which the pump laser contains a laser cathode ray tube.

Fig.9. Semiconductor disk laser with an active plate inside an evacuated flask.

The known device of the semiconductor disk laser, shown schematically in figure 1, contains an active plate 1 with a mirror coating 2 on its first surface 3, mounted on the first cold-conducting substrate 4, an external feedback mirror 5 and a pump laser 6. Mirror coating 2 and an external mirror feedback 5 form an optical resonator with an optical axis 7.

A semiconductor disk laser operates as follows. The radiation beam 8 of the pump laser 6 is directed to the second surface 9 of the active plate 1 near the optical axis 7. The beam 8 is absorbed by the active plate 1. In the absorption region, stimulated emission occurs, which, in the presence of feedback, generates directed radiation 10 emerging from the optical resonator through an external mirror 5.

Figure 2 presents the device of a semiconductor disk laser containing an active plate 11 with a mirror coating 12 on its first surface 13 and an additional coating 14 on its second surface 15, mounted on the first cold-conducting substrate 16, an external feedback mirror 17 and a pump laser 18. The mirror coating 12 and the external feedback mirror 17 form an optical resonator of a disk laser with an optical axis 18. The pump laser contains an active medium 19, a first feedback mirror 20, a first lens 21, and a second nzu 22 and second mirror feedback, communications 23. Mirrors 20 and 23, lenses 21 and 22 and the active plate 13 with its covers 12 and 14 form a stable optical resonator of the pump laser. In this embodiment, the additional coating 14 has a high transmittance at a wavelength of radiation from a disk laser and partially transmits at a wavelength of radiation from a pump laser, and the mirror coating 12 is highly reflective at wavelengths of radiation from a pump laser and a disk laser. In this case, the active plate 11 is made of a multilayer heterostructure with quantum wells separated by thick barrier layers having a band gap less than the energy of the pump radiation quantum.

A semiconductor disk laser operates as follows. The radiation 24 generated in the stable optical resonator of the pump laser is focused by lenses 21 and 22 at the intersection of the second surface 15 of the active plate 11 with the optical axis 18. This radiation is partially transmitted by the additional coating 14 into the active plate 11. The transmitted radiation is mainly absorbed by the active plate 11 in one run. Not absorbed in one pass, the radiation is reflected from the mirror coating 12 and is absorbed in the active plate in the second pass. As a result of absorption, nonequilibrium current carriers are generated in the active plate; most of them are formed in thick barrier layers. During their lifetime, nonequilibrium carriers have time to diffuse to quantum wells, where they are thermalized and recombine radiatively. At a high level of excitation, optical amplification occurs, which in the presence of feedback allows the generation of laser radiation 25, which leaves the resonator through the mirror 17.

On figa schematically presents another device node active plate with coatings and a cold conductive substrate. Here, an active plate of a multilayer heterostructure 26 with a mirror coating 27 on its first surface 28 and an additional coating 29 on its second surface 30 is fixed to the first cold-conducting substrate 31, through which the optical axis 32 of the disk laser resonator passes normal to the plate 26. Moreover, unlike the device in figure 2. the band gap of the barrier layers of a multilayer heterostructure is greater than the quantum of the pump laser radiation, and the additional coating is made highly transmitting for both the radiation of the disk laser and the radiation of the pump laser.

The device operates as follows. The generated radiation 33 is directed to a region near the point of intersection of the optical axis 32 with the second surface 30, passes through an additional coating 29 and penetrates deep into the active plate 26, partially absorbed by quantum wells. Then it is reflected from the mirror coating 27, again passes through the active plate, partially absorbed in the quantum wells, and leaves through the additional coating 29. In this case, the absorption in quantum wells significantly affects the pump laser generation mode, since it makes the main contribution to the loss of stable optical laser pump cavity. On the other hand, the radiation intensity inside the resonator is much higher, which ensures effective absorption in quantum wells, the total thickness of which is about 0.1 μm. As a result of absorption, luminescence and optical amplification occur, which in the presence of feedback leads to the generation of radiation from a 34 disk laser along the optical axis 32. As in the case shown in FIG. 2, the first cold-conducting substrate may be opaque.

On figb presents another embodiment of the node of the active plate with sputtering and the first cold conductive substrate. The active plate 35 with a mirror coating 36 on its first surface 37 and an additional coating 38 on its second surface 39 is mounted on the first cold-conducting substrate 40 with an antireflection coating 41. The normal to the active plate is the optical axis 42 of the stable optical disk laser resonator. In this case, the substrate is transparent to the radiation of a disk laser, the mirror coating 36 is made highly reflective at the wavelength of the radiation of the disk laser and partially transmits at the wavelength of the pump laser, the additional coating 38 is made of highly transmitting radiation from the disk laser and highly reflective at the wavelength of the pump laser radiation, and the active plate 35 is made of a multilayer heterostructure with quantum wells separated by thick barrier layers having a band gap greater than the quantum energy pump radiation.

The device operates as follows. The radiation 43 generated in the stable optical cavity of the pump laser is directed to the active plate 35 near the intersection of the first surface 37 of the active plate 35 with the optical axis 42. This radiation is partially transmitted by the mirror coating 36 into the active plate 35. The transmitted radiation is mainly absorbed by the active plate 35 in one run. Not absorbed in one pass, the radiation is reflected from the additional coating 38 and absorbed in the active plate in the second pass. As a result of absorption in the active plate, nonequilibrium current carriers are generated, which during their lifetime accumulate in quantum wells, where they are thermalized and recombined radiatively. At a high level of excitation, optical amplification occurs, which in the presence of feedback allows the generation of laser radiation 44 along the optical axis 42.

On figv presents a close embodiment of the node of the active plate with coatings and the first cold-conductive substrate, but intended for direct absorption by quantum wells of pump radiation. Here, the active plate 45 with a mirror coating 46 on its first surface 47 and an additional coating 48 on its second surface 49 is mounted on the first cold-conducting substrate 50 with an antireflection coating 51. The normal to the active plate is the optical axis 52 of the stable optical disk laser resonator.

The radiation 53 generated in the stable optical cavity of the pump laser is directed to the active plate 45 near the intersection of the first surface 47 of the active plate 45 with the optical axis 52. This radiation passes through the mirror coating 46 into the active plate 45, is partially absorbed by quantum wells, and is reflected from the additional coating 48, again passes through the active plate, partially absorbed by quantum wells, and exits through the mirror coating 46. As a result of absorption, luminescence and optical amplification e, which in the presence of the feedback leads to generation of radiation of the laser disk 54 along the optical axis 52.

Figure 4 shows a semiconductor disk laser containing an active plate 55 with a mirror coating 56 on its first surface 57 and an additional coating 58 on its second surface 59, mounted on the first cold-conducting substrate 60, an external feedback mirror 61 and a pump laser 62. Mirror coatings 56 and 58 and an external feedback mirror 61 form an optical cavity of a disk laser with an optical axis 63. The pump laser contains the active medium in the form of an array of active elements 64, the first feedback mirror 65, per the lens 66, the second lens 67 and the second feedback mirror 68. The mirrors 65 and 68, the lenses 66 and 67 and the active plate 55 with their coatings 56 and 58 form a stable optical pump laser resonator. In this embodiment, the additional coating 58 has a high transmittance at a wavelength of radiation from a disk laser and partially transmits at a wavelength of radiation from a pump laser, and the mirror coating 56 is highly reflective at wavelengths of radiation from a pump laser and a disk laser. In this case, the active plate 55 is made of a multilayer heterostructure with quantum wells separated by thick barrier layers having a band gap less than the energy of the pump radiation quantum.

A semiconductor disk laser operates as follows. Consider one element 69 of the matrix of active elements 64. When it is excited, radiation 70 is generated. This radiation excites the region of the active plate lying near the intersection of the second surface 59 with the optical axis 63. The excitation is as follows. The radiation 70 is partially transmitted by the additional coating 58 inside the active plate 55. The transmitted radiation is mainly absorbed by the active plate 55 in one pass. Not absorbed in one pass radiation is reflected from the mirror coating 56 and is absorbed in the active plate for the second pass. At the same time or sequentially in time, another element 71 is excited, which generates radiation 72. This radiation, like radiation 70, partially passes into the active plate 55 and excites it. Similarly, other elements of the matrix of active elements can be excited and generate their radiation. Radiation from all elements is summed up on the surface of the active plate. As a result of absorption in the active plate, nonequilibrium current carriers are generated, which during their lifetime accumulate in quantum wells, where they are thermalized and recombined radiatively. At a high level of excitation, optical amplification occurs, which, in the presence of feedback, allows the generation of laser radiation 73, which leaves the resonator through the mirror 61. The active elements can be laser diodes with side output (through chips) or surface-emitting laser diodes. Their excitation is carried out by injection current through electrical contacts.

5. presents a semiconductor disk laser containing an active plate 75 with a mirror coating 76 on its first surface 77 and an additional coating 78 on its second surface 79, mounted on the first cold-conducting substrate 80, an external feedback mirror 11 and a pump laser 82. Mirror coatings 76 and 78 and an external feedback mirror 81 form an optical resonator of a disk laser with an optical axis 83. The pump laser 82 comprises a laser cathode ray tube 84 with an electron-optical axis 85 containing in a vacuum the second flask 86 is an electron source (cathode) 87, a system of electrodes 88 forming an electron beam, and a second active plate 89 with a highly reflective coating 90 on its first surface 91, mounted on the second cold-conducting plate 92, as well as a focusing system 93 and an electron beam deflection 94 located outside the evacuated flask 86. Additionally, the pump laser contains a first lens 95, a second lens 96 and a second feedback mirror 97. The mirrors 89 and 97, the lenses 95 and 96 and the active plate 75 with their coatings 76 and 78 form a stable optical a pump laser cavity with an optical axis coinciding with the electron-optical axis 85. In this embodiment, the additional coating 78 has a high transmittance at the radiation wavelength of the disk laser and partially transmits at the radiation wavelength of the pump laser, and the mirror coating 76 is highly reflective at wavelengths of radiation from a pump laser and a disk laser. The active plate 75 is made of a multilayer heterostructure with quantum wells separated by thick barrier layers having a band gap less than the energy of the pump radiation quantum; and the second cold conductive substrate 92 is simultaneously the output optical window of the evacuated flask 86.

A semiconductor disk laser operates as follows. When an electric voltage is applied to the electron source 87 and the electrode system 88, an electron beam 98 is formed, which, when certain signals are applied to the focusing system 93 and the deviation 94, is focused to a certain region 99 of the second active plate 89. When this region is excited by an electron beam, radiation 100 is generated. This the radiation excites the region of the active plate lying near the intersection point of the second surface 79 with the optical axis 83. The excitation occurs as follows. Radiation 100 is partially transmitted by an additional coating 78 inside the active plate 75. The transmitted radiation is mainly absorbed by the active plate 75 in one pass. Non-absorbed radiation in one pass is reflected from the mirror coating 76 and absorbed in the active plate in a second pass. As a result of absorption in the active plate, nonequilibrium current carriers are generated, which during their lifetime accumulate in quantum wells, where they are thermalized and recombined radiatively. At a high level of excitation, optical amplification occurs, which, in the presence of feedback, allows the generation of laser radiation 101, which leaves the resonator through the mirror 81. By supplying a time-varying signal to the deflecting system 94, the electron beam scans along the surface of the second active plate 89. In this case, the pump mode active plate 75 remains constant in time, thereby achieving continuous generation in a semiconductor disk laser.

In Fig.6. A semiconductor disk laser with another embodiment of a laser cathode ray tube is presented. It contains an active plate 105 with a mirror coating 106 on its first surface 107 and an additional coating 108 on its second surface 109, mounted on the first cold-conducting substrate 110, an external feedback mirror 111 and a pump laser 112. Mirror coatings 106 and 108 and an external feedback mirror communications 111 form an optical resonator of a disk laser with an optical axis 113. The pump laser 112 comprises a laser cathode ray tube 114 with an electron-optical axis 115 containing an electron source (cathode) in the evacuated flask 116 117, an electron beam forming electrode system 118, and a second active plate 119 with a highly reflective coating 120 on its first surface 121 and an additional coating 122 on its second surface 123, mounted on the second cold-conducting plate 124, as well as a focusing system 125 and an electronic deflection 126 beams located outside the evacuated flask 116. Additionally, the pump laser 112 contains a first lens 127, a second lens 128 and a second feedback mirror 129. Mirrors 120 and 129, lenses 127 and 128 and an active plate 105 with their own coatings and 106 and 108 form a stable optical pump laser cavity with an optical axis 130. In this embodiment, the additional coating 108 has a high transmittance at the radiation wavelength of the disk laser and partially transmits at the radiation wavelength of the pump laser, and the mirror coating 106 is highly reflective at lengths radiation waves of a pump laser and a disk laser. The active plate 105 is made of a multilayer heterostructure with quantum wells separated by thick barrier layers having a band gap less than the energy of the pump radiation quantum; and the first lens 127 is simultaneously the output optical window of the evacuated flask 116.

A semiconductor disk laser operates as follows. When an electric voltage is applied to the electron source 117 and the electrode system 118, an electron beam 131 is formed, which, when certain signals are applied to the focusing system 125 and the deviation 126, is focused to a certain region 132 of the second active plate 119. When this region is excited by an electron beam, radiation 133. This radiation excites the region of the active plate lying near the intersection point of the second surface 109 with the optical axis 113. Excitation occurs as follows. Radiation 133 is partially transmitted by an additional coating 108 inside the active plate 105. The transmitted radiation is mainly absorbed by the active plate 105 in one pass. Non-absorbed radiation in one pass is reflected from the mirror coating 106 and absorbed in the active plate in a second pass. As a result of absorption in the active plate, nonequilibrium current carriers are generated, which during their lifetime accumulate in quantum wells, where they are thermalized and recombined radiatively. At a high level of excitation, optical amplification occurs, which in the presence of feedback allows the generation of laser radiation 134, which leaves the resonator through the mirror 111. By supplying a time-varying signal to the deflecting system 126, the electron beam scans along the surface of the second active plate 119. In this case, the pump mode active plate 105 remains constant over time, thereby achieving continuous generation in a semiconductor disk laser.

7. A semiconductor disk laser is presented, which contains two laser cathode ray tubes in a single vacuum flask. The semiconductor disk laser contains an active plate 135 with a mirror coating 136 on its first surface 137 and an additional coating 138 on its second surface 139, mounted on the first cold-conducting substrate 140 with an antireflection coating 141, an external feedback mirror 142 and a pump laser 143. Mirror coatings 136 and 138 and an external feedback mirror 142 form an optical resonator of a disk laser with an optical axis 144. The pump laser 143 comprises a first and a second electron beam cathode ray tube 145 and 146 axes 147 and 148, placed in a single evacuated flask 149. Each tube contains an electron source (cathode) 150 and 151, a system of electrodes 152 and 153, as well as focusing systems 154, 155 and deflections 156, 157 of the electron beam located outside the evacuated flasks 149. The evacuated flask 149 also contains a second active plate 158 with a highly reflective coating 159 on its first surface 160, mounted on a second cold-conducting plate 161 with an antireflective coating. Additionally, the pump laser 143 includes a lens 162 with antireflection coatings. Mirrors 159, lens 160, and active plate 135 with their coatings 136 and 138 form a stable optical pump laser cavity with an optical axis 163. In this embodiment, the additional coating 138 has a high transmittance at a wavelength of radiation from a disk laser and a high reflectance at a wavelength of the pump laser, and the mirror coating 136 is highly reflective at the wavelengths of the radiation of the disk laser and partially transmits at the wavelength of the pump laser. In this case, the active plate 135 is made of a multilayer heterostructure with quantum wells separated by thick barrier layers having a band gap less than the energy of the pump radiation quantum; and the second cold conducting substrate 161 is simultaneously the output optical window of the evacuated flask 149.

A semiconductor disk laser operates as follows. When voltage is applied to the electron sources 150 and 151 and the electrode system 152 and 153, two electron beams 164 and 165 are simultaneously formed, which, when certain signals are applied to the focusing systems 154, 155 and deviations 156, 157, are focused in certain areas 166 and 167 of the second active plates 158. These regions are symmetrical about the optical axis 163. When the electron beams excite regions 166 and 167, radiation 168 is generated. This radiation excites the region of the active plate lying near the intersection point of the first surface 137 with an optical axis 163. Excitation occurs as follows. Radiation 168 is partially transmitted by mirror coating 136 into the active plate 135. Passed radiation is mainly absorbed by the active plate 135 in one pass. Non-absorbed radiation in one pass is reflected from mirror coating 138 and absorbed in the active plate in a second pass. As a result of absorption in the active plate, nonequilibrium current carriers are generated, which during their lifetime accumulate in quantum wells, where they are thermalized and recombined radiatively. At a high level of excitation, optical amplification occurs, which, in the presence of feedback, makes it possible to generate laser radiation 169 emerging from the resonator through the mirror 142. By supplying consistent, time-varying signals to the deflecting systems 156 and 157, the electron beams are scanned along the surface of the second active plate 158 such so that the excitation regions always remain symmetric about axis 163. In this case, the pump mode of the active plate 135 remains constant in time, thereby achieving a continuous mode hydrochloric generation in a semiconductor disk laser.

On Fig. A semiconductor disk laser with two external feedback mirrors is presented, in which the pump laser contains a laser beam tube. The semiconductor disk laser contains an active plate 170 with a mirror coating 171 on its first surface 172 and an additional coating 173 on its second surface 174, mounted on the first cold-conducting substrate 175, the first and second feedback mirrors 176, 177 and the pump laser 178. Mirror coatings 171 and 173 and external feedback mirrors 176 and 177 form an optical resonator of a disk laser with an optical axis 179. The pump laser 178 contains a laser cathode ray tube 180 with an electron-optical axis 181 along which kuumiruemoy flask 182 has an electron source (cathode) 183, the electrode system 184 and focusing system 185 and deflecting the electron beam 186 is disposed evacuated flask. The evacuated flask 182 also contains a second active plate 187 with a highly reflective coating 188, mounted on the first half of the second refrigerant plate 189 with a similar highly reflective coating 190 in the second half and with an antireflection coating 191. Additionally, the pump laser 178 contains a lens 192 with antireflective coatings. Mirror coatings 188 and 190, lens 192 and active plate 170 with their coatings 171 and 173 form a stable optical pump laser cavity with an optical axis coinciding with the electron-optical axis 181. In this embodiment, the additional coating 173 has a high transmittance at a wavelength radiation of the disk laser and partially transmits at the wavelength of the radiation of the pump laser, and the mirror coating 171 is highly reflective at the wavelengths of the radiation of the pump laser and the disk laser. The active plate 170 is made of a multilayer heterostructure with quantum wells separated by thick barrier layers having a band gap less than the energy of the pump radiation quantum; and the second cold conducting substrate 189 is simultaneously the output optical window of the evacuated flask 182.

A semiconductor disk laser operates as follows. When voltage is applied to the electron source 183 and electrode system 184, an electron beam 193 is formed, which, when signals are applied to the focusing systems 185 and deviations 186, is focused into the region 194 of the second active plate 187. When the electron beam is excited by the region 194, radiation 195 is generated. This radiation excites the region of the active plate lying near the intersection point of its second surface 174 with the optical axis 181. The excitation occurs as follows. Radiation 195 is partially transmitted by the mirror coating 173 into the active plate 170. But most of the radiation reflected from the mirror coating 173 is directed by the lens 192 onto the highly reflective coating 190 to the region 196. The region 196 is symmetrical to the region 194 relative to the axis 181. The radiation transmitted to the active plate 170 is absorbed it is mainly in one pass. Non-absorbed radiation in one pass is reflected from the mirror coating 171 and absorbed in the active plate in a second pass. As a result of absorption in the active plate, nonequilibrium current carriers are generated, which during their lifetime accumulate in quantum wells, where they are thermalized and recombined radiatively. At a high level of excitation, optical amplification occurs, which in the presence of feedback allows the generation of laser radiation 197, which leaves the resonator through the mirror 177. When a time-varying signal is applied to the deflecting system 186, the electron beam scans along the surface of the second active plate 187. In this case, the pump mode active plate 170 remains constant in time, thereby achieving continuous generation in a semiconductor disk laser.

Figure 9 shows a semiconductor disk laser with an active plate inside an evacuated flask. It contains in a vacuum flask 200 with an electron-optical axis 201 and an output optical window 202 having a concave surface with a mirror coating 203, an electron source 204 located along this axis, an electrode system 205 for forming an electron beam, an active plate 206 with a mirror coating 207 on its first surface 208 and an additional coating 209 on its second surface 210, mounted on a first cold-conducting substrate 211, on which, on one side of the active plate 206, a second active plate 21 is placed 2 with a highly reflective coating 213 and an additional coating 214, and on the other hand from the active plate 206, a highly reflective coating 215 is sprayed onto the first cold conductive substrate 211. Outside of the evacuated bulb, focusing systems 216 and electron beam deflection 217 are placed. Mirror coatings 207, 209 and 203 form an optical resonator of a disk laser with an optical axis 218, and mirror coatings 213, 203, 209, 207 and 215 form a stable optical pump laser resonator. The additional coating 214 is highly transmissive for the radiation of the pump laser, the coating 209 is highly transmissive for the radiation of the pump laser and the disk laser, the mirror coating 207 is highly reflective for the radiation of the pump laser and the disk laser, and the active plate 206 is made of a multilayer heterostructure with quantum wells separated by barrier layers, the band gap of which is greater than the quantum energy of the pump laser.

The device operates as follows. When an electric voltage is applied to the electron source 204 and the electrode system 205, an electron beam 219 is formed, which, when signals are sent to the focusing systems 216 and deviations 217, focuses in the region 220 on the second active plate 212. In this region, the electron beam is absorbed, luminescence arises in it and optical amplification, which in the presence of feedback leads to the generation of laser radiation. An M-shaped mode 221 is generated that is symmetrical about the optical axis 218. This mode penetrates into the active plate 206, where the generated radiation is partially absorbed directly by quantum wells. As a result of this absorption, nonequilibrium carriers, their radiative recombination, and optical amplification appear in quantum wells. In the presence of feedback, generation occurs in the disk laser along the axis 218. Through the mirror coating 203 and the window 202, the generated radiation 222 leaves the evacuated bulb. When a time-varying signal is applied to the deflecting system 217, the electron beam scans over the surface of the second active plate 212. In this case, the pumping mode of the active plate 206 remains constant in time, thereby achieving continuous generation in a semiconductor disk laser.

The inventive device is illustrated by the following example. The semiconductor disk laser is made in the form of a sealed device (see Fig.9). The device has the shape of a cylinder with a diameter of 30 mm, to which a cathode ray tube 80 mm long is welded from top to side. The cathode ray tube contains a cathode and an electrode system for generating an electron beam. On the tube from the outside are electromagnetic coils of focusing and deviation. An optical window is welded in the upper part of the cylinder, having an external flat surface and an internal concave surface, similar in shape to a paraboloid of revolution with a radius of curvature in the central part of 30 mm. A mirror coating is sprayed onto this surface. A copper cold-conducting substrate is welded to the bottom of the cylinder through a bellows connection, to which an active GaInP / AlGaInP heterostructure with transverse dimensions of 3 × 3 mm and a thickness of 1 μm emitting at a wavelength of 640 nm is soldered to its central part. It contains 10 QWs with a thickness of 8 nm each. From the substrate side, a mirror coating of Ta2O5-SiO2 oxides and Al layer is sprayed onto the heterostructure. The reflection coefficient of this mirror is above 0.999 in the range of 660-610 nm. An antireflection coating with a residual reflection coefficient less than 0.001 is sprayed onto the second surface of the heterostructure.

On the one hand, from this heterostructure, a second GaInP / AlGaInP heterostructure with transverse dimensions of 10 × 10 mm and a thickness of 3 μm, radiating at a wavelength of 625 nm, is welded to the cold-conducting substrate. A mirror coating of Ta2O5-SiO2 oxides and Al layer is sprayed onto the surface from the side of the substrate. The reflection coefficient of this mirror is above 0.999 in the region of 640-610 nm. An antireflection coating with a residual reflection coefficient less than 0.001 is sprayed onto the second surface of the heterostructure. On the other hand, from the first heterostructure, a reflective coating of Ta2O5-SiO2 oxides and Al layer is sprayed onto the cold-conducting substrate. The reflection coefficient of this mirror is above 0.999 in the region of 640-610 nm. A Peltier element is docked to the outside of the copper substrate to remove the heat generated. The substrate is also equipped with a mechanism for smoothly tilting the substrate in two directions to align the optical resonator. The distance between the substrate and the inner surface of the output window along the axis of the resonator is 15 mm

An electron beam with an electron energy of 25 keV and a current of 2 mA is formed in the cathode ray tube. It focuses on a 100 μm spot and scans over an area of 10 × 10 mm ² . An M-shaped mode is excited in the optical cavity. The main losses of this mode are the absorption losses in the quantum wells of the first heterostructure. They absorb power of about 5 watts. This power with coefficients greater than 0.8 is converted to collimated radiation from a disk laser. The output radiation power is 4 watts. The total power consumption of the laser is 70 watts.

Claims (23)

1. A semiconductor disk laser containing an active plate with a mirror coating on the first surface, mounted on the first cold-conducting substrate, an external feedback mirror and a pump laser, the active plate being between the mirror coating and the external feedback mirror, which are elements of an optical resonator of a disk laser and the pump laser has its own stable optical resonator and the wavelength of its radiation is shorter than the radiation wavelength of the disk laser, characterized in that it is active The disk laser plate is one of the reflective elements of a stable optical cavity of the pump laser, and when the radiation generated in the pump laser is reflected from the active plate, a part of the radiation is partially absorbed in the active plate, thereby exciting the disk laser. 2. The semiconductor disk laser according to claim 1, characterized in that the active plate faces the first cold-conducting substrate with its first side with a mirror coating, which is made highly reflective at the radiation wavelength of the disk laser and the wavelength of the pump laser, and on the second surface of the active plate an additional coating is applied which is highly transmittable at a wavelength of radiation from a disk laser and which transmits at least partially at a wavelength of radiation of a pump laser. 3. The semiconductor disk laser according to claim 1, characterized in that the active plate faces the first cold-conducting substrate with its second side, which is coated with an additional dichroic mirror coating, high transmission radiation from the disk laser and highly reflective radiation from the pump laser, and the mirror coating on the first side of the active The area is highly reflective at a wavelength of radiation from a disk laser and transmits at least partially at a wavelength of radiation of a pump laser. 4. A semiconductor disk laser according to any one of claims 2 and 3, characterized in that the pump laser contains a matrix of active elements, and a stable optical resonator has an optical axis along which the first feedback mirror, the matrix of active elements, the first lens with antireflective are sequentially arranged coatings, an active plate of a disk laser, a second lens with antireflection coatings and a second common feedback mirror, the point of intersection of the optical axis with the first surface of the active plate refracting pticheskuyu axis located near the rear focal plane of the first lens and the vicinity of the front focal plane of the second lens. 5. A semiconductor disk laser according to any one of claims 2 and 3, characterized in that the pump laser contains a matrix of surface-emitting semiconductor elements with longitudinal injection pumping, and a stable optical resonator has an optical axis along which the first feedback mirror is arranged in series, the matrix is surface emitting semiconductor elements, the first lens with antireflection coatings, the active plate of a disk laser, the second lens with antireflection coatings and a second common mirror contact, and the point of intersection of the optical axis with the first surface of the active plate refracting the optical axis is located near the rear focal plane of the first lens and near the front focal plane of the second lens. 6. The semiconductor disk laser according to claim 2, characterized in that the pump laser comprises a laser cathode ray tube with an electron-optical axis, comprising, in a vacuum flask with an output optical window, an electron source and an electrode system sequentially arranged along the electron-optical axis electron beam, a second active plate with a highly reflective mirror coating on its first surface, mounted on a second cold-conducting substrate, as well as focusing and deflection systems electrons beam placed outside a vacuum flask; a stable optical resonator has an optical axis along which a second active plate with a highly reflective mirror coating inside the evacuated flask and a first lens with antireflective coatings, an active disk laser plate, a second lens with antireflective coatings and a second external feedback mirror located outside the evacuated flask are sequentially placed; moreover, the point of intersection of the optical axis with the first surface of the active plate refracting the optical axis is located near the rear focal plane of the first lens and near the front focal plane of the second lens. 7. The semiconductor disk laser according to claim 3, characterized in that the pump laser comprises a laser cathode ray tube with an electron-optical axis, comprising, in a vacuum flask with an output optical window, an electron source and an electrode system sequentially arranged along the electron-optical axis electron beam, a second active plate with a highly reflective mirror coating on its first surface, mounted on a second cold-conducting substrate, as well as focusing and deflection systems electrons beam placed outside a vacuum flask; a stable optical resonator has an optical axis along which a second active plate with a highly reflective mirror coating inside the evacuated flask and a first lens with antireflective coatings, an active disk laser plate, a second lens with antireflective coatings and a second external feedback mirror located outside the evacuated flask are sequentially placed; moreover, the point of intersection of the optical axis with the first surface of the active plate refracting the optical axis is located near the rear focal plane of the first lens and near the front focal plane of the second lens. 8. The semiconductor disk laser according to claim 2, characterized in that the pump laser is made in the form of a first and second laser cathode ray tube with an electron-optical axis, each of which contains in a vacuum flask with an output optical window sequentially located along the electron-optical axis an electron source, an electrode system for forming an electron beam, a second active plate with a highly reflective mirror coating on its first surface, mounted on a second cold-conducting substrate, and that also focusing systems and deviations of the electron beam, placed outside the evacuated bulb; a stable optical resonator has an optical axis along which a second active plate with a highly reflective coating of the first laser cathode ray tube, a first lens with antireflection coatings, an active disk laser plate, a second lens with antireflection coatings, and a second active plate with a highly reflective mirror coating are arranged second laser cathode ray tube; moreover, the point of intersection of the optical axis with the first surface of the active plate refracting the optical axis is located near the rear focal plane of the first lens and near the front focal plane of the second lens, and the electron beam deflection systems provide optical coupling of the excitation region of the second active plate of the first laser cathode ray tube with the excitation region of the second active plate of the second laser cathode ray tube. 9. The semiconductor disk laser according to claim 3, characterized in that the pump laser is made in the form of first and second laser cathode ray tubes with an electron-optical axis, each of which contains in a vacuum flask with an output optical window sequentially located along the electron-optical axis an electron source, an electrode system for forming an electron beam, a second active plate with a highly reflective mirror coating on its first surface, mounted on a second cold-conducting substrate, and that also focusing systems and deviations of the electron beam, placed outside the evacuated bulb; a stable optical resonator has an optical axis along which a second active plate with a highly reflective coating of the first laser cathode ray tube, a first lens with antireflection coatings, an active disk laser plate, a second lens with antireflection coatings, and a second active plate with a highly reflective mirror coating are arranged second laser cathode ray tube; moreover, the point of intersection of the optical axis with the first surface of the active plate refracting the optical axis is located near the rear focal plane of the first lens and near the front focal plane of the second lens, and the electron beam deflection systems provide optical coupling of the excitation region of the second active plate of the first laser cathode ray tube with the excitation region of the second active plate of the second laser cathode ray tube. 10. The semiconductor disk laser according to claim 8, characterized in that the first and second laser cathode ray tubes are placed in a single evacuated flask with a single exit window, the second active plate of the first laser cathode ray tube and the second active plate of the second laser cathode ray the tubes are a single second active plate mounted on a single second cold-conducting substrate, and the first and second lenses are combined in a single lens with antireflection coatings. 11. The semiconductor disk laser according to claim 9, characterized in that the first and second laser cathode ray tubes are placed in a single evacuated flask with a single exit window, the second active plate of the first laser cathode ray tube and the second active plate of the second laser cathode ray the tubes are a single second active plate mounted on a single second cold-conducting substrate, and the first and second lenses are combined in a single lens with antireflection coatings. 12. The semiconductor disk laser according to claim 2, characterized in that the pump laser comprises a laser cathode ray tube made in the form of an evacuated bulb with an output optical window and having an electron optical axis along which an electron source is arranged in series, an electrode system for forming the electron beam and the second active plate with a highly reflective mirror coating on the first surface, mounted on the first half of the second cold-conducting substrate, in which the second half has an ogichnoe highly reflective mirror coating and the focusing system and deflecting the electron beam tube is placed; a stable optical resonator has an optical axis along which a second cold conductive substrate with a second active plate and a highly reflective mirror coating is placed on and off the first surface of the second active plate, an antireflection lens and an active disk laser plate, the first surface of which is located near the rear focal plane lenses; moreover, the deposition region of the highly reflective mirror coating on the first surface of the second active plate has a mirror symmetric region of the deposition of highly reflective mirror coating on the second half of the cold-conducting substrate relative to the optical axis of the stable optical resonator, and the electron beam deflection system ensures that the excitation region of the second active plate is located within the region with the highly reflective mirror coating on its first surface. 13. The semiconductor disk laser according to claim 3, characterized in that the pump laser comprises a laser cathode ray tube made in the form of an evacuated bulb with an output optical window and having an electron optical axis along which an electron source is arranged in series, an electrode system for forming the electron beam and the second active plate with a highly reflective mirror coating on the first surface, mounted on the first half of the second cold-conducting substrate, in which the second half has an ogichnoe highly reflective mirror coating and the focusing system and deflecting the electron beam tube is placed; a stable optical resonator has an optical axis along which a second cold conductive substrate with a second active plate and a highly reflective mirror coating is placed on and off the first surface of the second active plate, an antireflection lens and an active disk laser plate, the first surface of which is located near the rear focal plane lenses; moreover, the deposition region of the highly reflective mirror coating on the first surface of the second active plate has a mirror symmetric region of the deposition of highly reflective mirror coating on the second half of the cold-conducting substrate relative to the optical axis of the stable optical resonator, and the electron beam deflection system ensures that the excitation region of the second active plate is located within the region with the highly reflective mirror coating on its first surface. 14. A semiconductor disk laser according to any one of claims 6, 7, 10-13, characterized in that the second cold conducting substrate is made transparent, the second active plate is fixed to the second cold conducting substrate with its second side, the output optical window is located between the second active plate and the first lens, and the excitation of the second active plate is through a highly reflective mirror coating deposited on its first surface. 15. A semiconductor disk laser according to any one of claims 6, 7, 10-13, characterized in that the second cold conducting substrate is transparent and is at the same time the output optical window of the evacuated bulb with an external surface having an antireflective coating, the second active plate is fixed to the second cold conducting the substrate with its second side, and the second active plate is excited through a highly reflective mirror coating deposited on its first surface. 16. A semiconductor disk laser according to any one of claims 6, 7, 10-13, characterized in that the second cold conducting substrate is transparent, has a flat and convex surface and is simultaneously the exit window of the evacuated flask and the first lens, the second active plate is mounted on a flat the surface of the second cold conducting substrate with its second side, and the second active plate is excited through a highly reflective mirror coating deposited on its first surface. 17. A semiconductor disk laser according to any one of claims 6, 7, 10-13, characterized in that the second active plate is fixed to the second cold-conducting substrate by its first side, the output optical window is located between the second active plate and the active plate of the disk laser and has antireflective coating, and the excitation of the second active plate is carried out through its second surface. 18. A semiconductor disk laser according to any one of claims 6, 7, 10-13, characterized in that the second active plate is fixed on the second cold-conducting substrate with its first side, the output optical window of the evacuated bulb is simultaneously the first lens, located between the second active plate and active plate of a disk laser and has antireflection coatings, and the second active plate is excited through its second surface. 19. The semiconductor disk laser according to claim 1, characterized in that the pump laser comprises a laser cathode ray tube made in the form of an evacuated bulb with an output optical window and having an electron optical axis along which an electron source is arranged in series, an electrode system for forming the electron beam and the second active plate with a highly reflective coating on its first surface, mounted on the first cold-conductive substrate, as well as focusing systems and deviations of the electron beam ka placed outside the tube; moreover, the active plate of the disk laser is fixed in the Central part of the first cold-conducting substrate with its first surface with a mirror coating, which is made highly reflective for the wavelength of the radiation of the pump laser and the radiation wavelength of the disk laser; on the one side of this plate, the second active plate is fixed with its first surface with a highly reflective mirror coating at the wavelength of the pump laser radiation, and on the other hand a highly reflective coating is sprayed, similar to the coating deposited on the first surface of the second active plate; an antireflection coating is applied to the second surface of the second active plate, through which the electron beam excites the second active plate; on the second surface of the active disk of the disk laser, a coating is applied that is highly transparent at the wavelength of the radiation of the disk laser and passes at least partially at the wavelength of the radiation of the pump laser, through which optical pumping of the disk laser is performed; the external feedback mirror of the disk laser is made in the form of an output window of a vacuum flask, in which the surface facing the second surface of the active plate of the disk laser is concave and a mirror coating is sprayed on it, which is highly reflective for the wavelength of the pump laser radiation and partially transmits at the wavelength radiation from a disk laser, at least in the central part of the output window; the first surfaces of the active plate of the disk laser and the second active plate, as well as the outer surface of the highly reflective mirror coating deposited on part of the surface of the first cold-conducting substrate, are located near the focal plane of the external mirror; the optical resonator of the disk laser and the stable optical resonator of the pump laser have a single optical axis that passes through the central part of the first cold-conducting substrate, coinciding with its normal; the surface of the second active plate has an axisymmetric region with a highly reflective mirror coating on the surface of the first cold conducting substrate outside the plate; the shape of the concave surface is close to the paraboloid of rotation around the optical axis. 20. The semiconductor disk laser according to claim 1, characterized in that the active plate is made of a multilayer heterostructure with quantum wells. 21. A semiconductor disk laser according to any one of claims 6, 7, 10-13 and 19, characterized in that the active plate of the disk laser and the second active plate are made of multilayer heterostructures with quantum wells or quantum dots. 22. The semiconductor disk laser according to any one of claims 6, 7, 10-13 and 19, characterized in that the active plate of the disk laser and the second active plate are made of multilayer heterostructures with quantum wells or quantum dots, the layers of the heterostructure being made of A2B6 compounds or A3B5. 23. A semiconductor disk laser according to any one of claims 6, 7, 10-13, characterized in that the lenses are made with small spherical aberration.

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