RU2443044C1 - Injection laser - Google Patents

Abstract

FIELD: optics.

SUBSTANCE: heterostructure based laser contains waveguide layer placed between wide-gap emitters of p and n-conductivity type that are simultaneously the limiting layers, active zone consisting of quantum-dimensional active layer, optical Fabry-Perot cavity and stripe ohmic contact under which the injection zone is located. In the waveguide layer outside the injection area there is the introduction of the area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area. The factor of optical confinement of closed mode of abovementioned semiconductor material fits the ratio:

where:

- values of the compounds of optical confinement factor G for closed mode in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, relative units; α_NB - optical losses related to interband absorption of closed mode radiation in the introduced area of semiconductor material with the width of energy gap that is less than the width of energy gap of active area, cm^-1.

EFFECT: increase of output optic power in both continuous and pulse current injection mode, as well as increased time stability of output active power.

13 cl, 4 dwg

Description

The present invention relates to quantum electronic technology, and more specifically to high-power semiconductor lasers.

Powerful semiconductor lasers are widely used in many fields of science and technology, for example, they are used as a source of optical radiation for pumping fiber amplifiers, fiber and solid-state lasers. This requires a semiconductor laser to combine maximum efficiency and radiation power. The development of new approaches to the design of high-power semiconductor lasers has significantly improved the optical parameters of heterostructures. For modern semiconductor lasers, the internal optical loss is less than 1 cm ^-1 with an internal quantum yield close to 100%. The high optical perfection of laser heterostructures and low optical losses make it possible to achieve continuous and pulsed excitation levels of several tens of amperes. The consequence of such changes in the characteristics of laser heterostructures and excitation levels is the emergence of new effects, a number of which lead to saturation of the watt-ampere characteristic and a decrease in the maximum output radiation power.

An injection laser is known (patent US 7332744, IPC H01L 29/24, published February 19, 2008), in which the current-limiting layer includes an unoxidized region based on AlAs or a similar material suitable for creating a current injection region in the active layer and an oxidized region made on the basis of aluminum oxide, corresponding to the region in which there is no injection current. The oxidized region is made on the basis of unoxidized AlAs or similar materials, part of which is oxidized at temperatures from 240 ° C to 375 ° C. The thickness of the oxidized region is preferably chosen from 10 to 1000 nm. The width of one side of the oxidized region is equal to or greater than the width of the non-oxidized region. The distance between the current-limiting layers and the active layer is 50 nm or more or 500 nm or less, and more preferably 180 nm or more.

The disadvantage of the proposed injection laser is the lack of technical solutions to suppress the generation of a closed mode. As a result, the output optical power during laser generation does not reach the maximum possible values.

An injection laser is known (see patent RU No. 2230410, IPC H01S 5/042, published June 10, 2004), which includes a laser heterostructure with waveguide layers, in one of the limiting layers of which there are relief structures, at least part of the mesa strip and passive regions with bases near the boundary of the boundary layer closest to the active region. At least a portion of the base of each passive region is a relief structure adjacent to the messtrip, having in the direction perpendicular to the longitudinal axis of the resonator a length exceeding the distance providing scattering of radiation propagating in said direction perpendicular to the longitudinal axis of the resonator. Each relief structure has an amplitude of at least 0.1 μm and is distant from the mentioned boundary of the bounding layer by a distance not exceeding 0.5 μm.

The known laser has an increased output radiation power, a narrowed and improved spatial diagram of the output radiation in the p-n junction plane to a single-mode, an improved emission spectrum to a single-frequency, as well as stable parameters due to an increase in the absorption efficiency of undesirable high-order and ring modes, and optimization of the lateral optical limitation.

However, the well-known injection laser does not solve the problem of increasing the optical power, since laser heterostructures with low internal optical losses are characterized by a localization of the laser mode field close to 100% in the waveguide layers. In this case, any periodic structures formed in any restrictive layers become ineffective, because the laser mode field does not overlap with them.

Known injection laser (see No. 2230411, IPC H01S 5/034, published 06/10/2004), comprising a heterostructure containing an active layer, at least waveguide layers, boundary layers placed on both sides of it, as well as a mestripe of comb-like waveguide, formed from the p-type side of the heterostructure, with the base located in the bounding layer placed on the same side of the active layer. The boundary layer on the p-type side of the heterostructure is formed of at least two sublayers having the same composition. The restrictive first sublayer adjacent to the waveguide layer is either not doped or has a p-type concentration of not more than 3 · 10 ¹⁷ cm ^-3 . The next limiting sublayer adjacent to the first one has a p-type concentration of more than 3 · 10 ¹⁷ cm ^-3 , the messtrip of the crest-shaped waveguide is formed in two layers. The first tier is coaxially located on the second tier of the mesa strip additionally inserted into the restrictive first sublayer, having a width exceeding the width of the first tier of the mesa strip by 1.5-4 times.

In the known laser, a decrease in the series resistance of the laser is ensured with a minimum spreading profile, as well as stabilization of the single-mode lasing mode.

A disadvantage of the known laser is the presence of optical communication with areas lateral relative to the mesa strip. The absence of additional technical solutions that increase the internal optical loss in the side regions leads to the fulfillment of the threshold conditions for the generation of closed modes and a decrease in the output optical power.

The closest in technical essence and in the aggregate of essential features is an injection laser (see patent RU No. 2259620, IPC H01S 5/32, published August 27, 2005). The injection laser prototype contains a separate confinement heterostructure, including a multimode waveguide, the confining layers of which are simultaneously emitters of p- and n-type conductivity with the same refractive indices, an active region consisting of at least one quantum-dimensional active layer, the location of which in the waveguide and the thickness of the waveguide satisfy the relation

и

- факторы оптического ограничения для активной области нулевой моды и моды m (m=1, 2, 3…) соответственно. Инжекционный лазер содержит также отражатели, оптические грани, омические контакты и оптический резонатор. Активная область размещена в дополнительном слое, показатель преломления которого больше показателя преломления волновода, а толщина и расположение в волноводе определяются из условия выполнения упомянутого соотношения, причем расстояния от активной области до p- и n-эмиттеров не превышают длин диффузии дырок и электронов в волноводе соответственно.Where

and

are the optical confinement factors for the active region of the zero mode and mode m (m = 1, 2, 3 ...), respectively. The injection laser also contains reflectors, optical faces, ohmic contacts and an optical resonator. The active region is placed in an additional layer, the refractive index of which is greater than the refractive index of the waveguide, and the thickness and location in the waveguide are determined from the condition for the above relation to be fulfilled, and the distances from the active region to p- and n-emitters do not exceed the diffusion lengths of holes and electrons in the waveguide, respectively .

The known injection laser has a small divergence of radiation while maintaining a high value of efficiency and output power of the radiation.

A disadvantage of the known laser is the presence of optical communication with areas lateral relative to the mesa strip. The absence of additional technical solutions in the injection laser prototype that increase the internal optical loss in the side regions leads to the fulfillment of the threshold conditions for the generation of closed modes and a decrease in the output optical power.

The objective of the proposed technical solution was the development of such an injection laser design that would provide an increase in the output optical power in both continuous and pulsed current pumping modes, and increase the temporal stability of the output optical power.

The problem is solved in that the injection laser based on the heterostructure includes a waveguide layer enclosed between wide-gap p- and n-type emitters, which are simultaneously boundary layers, an active region consisting of at least one quantum-dimensional active layer, an optical Fabry-Perot resonator and strip ohmic contact, under which the injection region is located. At least one region of the semiconductor material with a band gap less than the band gap of the active region is introduced into the waveguide layer outside the injection region. The optical limitation factor of the ZM region of said semiconductor material satisfies the relation:

- значение составляющей фактора оптического ограничения Г_X для ЗМ во введенной области полупроводникового материала с шириной запрещенной зоны, меньшей ширины запрещенной зоны активной области, отн. ед.;Where

- the value of the component of the optical limiting factor G _X for ZM in the introduced region of the semiconductor material with the band gap less than the band gap of the active region, rel. units;

- значение составляющей фактора оптического ограничения Г_Y для ЗМ во введенной области полупроводникового материала с шириной запрещенной зоны, меньшей ширины запрещенной зоны активной области, отн. ед.;

- the value of the component of the optical limiting factor G _Y for ZM in the introduced region of the semiconductor material with the band gap less than the band gap of the active region, rel. units;

- значение составляющей фактора оптического ограничения Г_Z для ЗМ во введенной области полупроводникового материала с шириной запрещенной зоны, меньшей ширины запрещенной зоны активной области, отн. ед.;

- the value of the component of the optical limiting factor G _Z for ZM in the introduced region of the semiconductor material with a band gap less than the band gap of the active region, rel. units;

α _NB is the optical loss associated with interband absorption of ZM radiation in the introduced region of the semiconductor material with a band gap less than the band gap of the active region, cm ^-1 .

The distance between the nearest boundaries of the region of said semiconductor material and the injection region can be at least 10 μm, and the width of the region of the semiconductor material can be at least 10 μm.

The band gap of the region of said semiconductor material may be at least 20 meV less than the photon energy on the generation line of the injection laser.

The region of said semiconductor material may be made in the form of at least one quantum-dimensional layer or in the form of at least two quantum-dimensional layers with a different band gap.

The region of said semiconductor material may be made in the form of at least two quantum-dimensional layers with different forbidden gap widths, separated by a layer with a larger forbidden band width.

At least one region of said semiconductor material may be introduced into each side of the injection laser.

The longitudinal size of the region of said semiconductor material may be less than the length of the optical Fabry-Perot resonator.

The heterostructure of the injection laser can be performed in the A ³ B ⁵ solid solution system. heterostructure.

At least one boundary of the region of said semiconductor material may not be parallel to the laterally naturally cleaved faces forming the lateral bounding surfaces.

The region of said semiconductor material in the injection laser may be made of a doped n-type impurity selected from the group: Si, Te, Ge, Sn, or a combination thereof.

The region of said semiconductor material in the injection laser may be made of a doped p-type impurity selected from the group: C, S, Mg, Be, Zn, or a combination thereof.

Improving the output characteristics of the inventive injection laser is provided by suppressing the generation of ZM.

The inventive injection laser is illustrated by drawings, where

figure 1 shows a well-known injection laser with a strip ohmic contact;

figure 2 shows the inventive injection laser, in the lateral part of which is introduced a region of a semiconductor material with a band gap less than the band gap of the active region;

и

- материальное усиление соответственно ФПМ и ЗМ,

и

- потери на межзонное поглощение в пассивных областях соответственно для ФПМ и ЗМ);figure 3 shows the qualitative dependence of the material gain in the active strip (curve 1) and losses in the passive region (curve 2) on the wavelength (λ _FP and λ _СМ are the generation wavelengths, respectively, of the FPM and ZM,

and

- material gain, respectively, FPM and ZM,

and

- losses due to interband absorption in the passive regions for the MTF and ZM, respectively);

figure 4 shows the dependence of the output optical power exiting through the face coated with an antireflection coating, on the pump current for a known injection laser and the inventive injection laser (curve 7 for continuous pump current, curve 8 for pulsed pump current for a known laser; curve 9 - with a continuous pump current, curve 10 - with a pulsed pump current for the inventive injection laser).

The known injection laser (see Fig. 1) contains a waveguide layer 1, sandwiched between a wide-band p-type emitter 2 and a wide-band n-type emitter 3, an active region 4 consisting of at least one quantum-well active layer , an optical Fabry-Perot resonator formed by a naturally cleaved facet 5 with an antireflection coating and a facet 6 with a reflective coating, a strip ohmic contact 7, under which there is an injection region 8, including an amplification region 9 (shaded ana inclined solid lines), estestvennoskolotye side faces forming the lateral limiting surface 10, substrate 11, the side portions of the injection laser (shaded inclined broken lines) 12.

The inventive injection laser (see figure 2) contains a waveguide layer 1, sandwiched between a wide-gap p-type emitter 2 and a wide-band n-type emitter 3, an active region 4 consisting of at least one quantum-well active layer , an optical Fabry-Perot resonator formed by a naturally chipped face 5 with an antireflection coating and a face 6 with a reflective coating, a strip ohmic contact 7, under which there is an injection region 8, including an amplification region 9 (shaded solid inclined lines), naturally cracked lateral faces forming lateral boundary surfaces 10, substrate 11, injection laser side parts (hatched by oblique broken lines) 12, semiconductor material region 13 (shaded by straight vertical lines) with a band gap smaller than the band gap active area 4.

Improving the output characteristics of the inventive injection laser is provided by suppressing the generation of ZM. Injection lasers are characterized by a mode radiation structure, which is calculated using the wave equation [H. Casey, M. Panish. - Lasers on heterostructures. - M .: Mir, 1981; L.A. Coldren, S.W. Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)]. Two types of mod structures can be distinguished. The first is the Fabry-Perot resonator (FPM) mode. Such modes are characterized by the propagation of radiation along the optical axis of the resonator at angles to the normal to the resonator mirrors (naturally cleaved face 5 with an antireflection coating and face 6 with a reflective coating), smaller than the angle of total internal reflection. As a result, the PMF is characterized by nonzero losses on the output of radiation from the resonator. It is this radiation that is useful when using injection lasers as sources of optical radiation. The structures of the Fabry-Perot resonator modes are determined by the waveguides formed by the waveguide and emitter (restrictive) layers of the heterostructure (1, 2, 3), the ohmic strip contact 7, and the Fabry-Perot cavity mirrors (5, 6). The second type of mod structure is ZM. Such modes are characterized by the propagation of radiation at angles to the normals relative to the mirrors (5, 6) of the resonator and the lateral limiting surfaces 10, larger than the angle of total internal reflection. As a result, ZM is characterized by zero losses in the output of radiation from the resonator. ZM structures determine the waveguides formed by the waveguide and emitter (restrictive) layers (1, 2, 3) of the heterostructure, the ohmic strip contact 7, the Fabry-Perot cavity mirrors (5, 6), and the lateral bounding surfaces 10. The threshold generation conditions for the FPM or ZM determines the operation mode of the injection laser. When the generation threshold is fulfilled only for the FPM, the maximum useful output efficiency is achieved and, accordingly, the output optical power increases. When the threshold generation conditions for the ZM are fulfilled, part of the laser radiation does not come out and remains inside the injection laser. As a result, there is a partial or complete drop in the output optical power and a decrease in efficiency. In an injection laser, the threshold for laser mode generation is achieved when two conditions are satisfied: the modal gain is equal to the total optical loss and feedback is present. The first condition is satisfied due to the injection current flowing through the strip ohmic contact 7 and creating an inverse population by charge carriers of the active region 4 under the strip ohmic contact 7. Thus, in the active region 4 under the strip ohmic contact 7, conditions are created for amplification of optical radiation, and this part of the active region 4 is called the amplification region 9. For the lateral parts of the active region 4 relative to the strip ohmic contact 7, the conditions for amplification are not created, because they are electrically isolated from the injection current. However, there remains an optical connection between the side parts of the active region 4 and the amplification region 9 through a common waveguide layer 1. The second condition for injection lasers is satisfied by a resonator formed by naturally cleaved faces. Naturally cleaved faces form two types of resonators: the Fabry-Perot resonator is formed by two mirrors 5, 6 — parallelly cleaved faces, the ZM resonator is formed by four cleaved faces (mirrored faces 5, 6 and their orthogonal faces — lateral limiting surfaces 10), which limit the injection laser and obtained in the manufacture of an injection laser by splitting a heterostructure. In general terms, the threshold generation condition can be written as [L.A. Coldren, S.W. Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)]:

where G _mod is the modal gain created by the charge carriers injected into the active region 4, α _i are the internal optical losses in the gain region 9, and α _out are the losses associated with the exit of laser radiation from the cavity. Modal gain is expressed in terms of material gain (g _mat ), calculated through the concentration of 4 charge carriers injected into the active region [LAColdren, SWCorzine. - Diode lasers and photonic integrated circuits. (NY, John Wiley & Sons, 1995)], and the optical mode confinement factor (G) in gain region 9:

In general, the optical confinement factor in the amplification region 9 determines the fraction of the laser mode energy attributable to this region and is expressed through the electric field of the injection laser mode E (x, y, z) [L.A. Coldren, S.W. Corzine. - Diode lasers and photonic integrated circuits. (N.Y., John Wiley & Sons, 1995)]

where V _g is the volume of the amplification region 9, Vm is the volume of the injection laser. The fashion field is described as a work [LAColdren, SWCorzine. - Diode lasers and photonic integrated circuits. (NY, John Wiley & Sons, 1995)]

The optical mode confinement factor in the gain region 9 of the injection laser is expressed in terms of three independent components of the optical mode confinement factor in the gain region 9 _X , G _Y and G _Z (see FIG. 1).

In an injection laser with a strip ohmic contact 7, the width of the strip contact (w) exceeds the generation wavelength, and the Fabry-Perot cavity mirrors (5, 6) limit the gain region 9 in the direction parallel to the cavity axis. This allows the PPM field to be completely localized in the region limited by the dimensions of the strip ohmic contact 7 and the long resonator. This means for the FPM Г _Y = 1 and Г _Z = 1. FPM electromagnetic waves propagate along the Fabry-Perot axis of the resonator at angles smaller than the angle of total internal reflection relative to the normal to the Fabry-Perot mirror mirrors (5, 6) and are characterized by the outgoing radiation loss α _out . The component of the optical confinement factor Г _{X is the} same for ZM and FPM and depends on the design of the laser heterostructure: the composition and thickness of the waveguide and bounding layers (1, 2, 3), as well as the thickness of the active region 4. For laser heterostructures, Г _X is a factor of the optical mode confinement transverse waveguide in the active region 4 - G _QW . Then the threshold generation condition (1) for the MTF can be rewritten as

- материальное усиление на длине волны генерации ФПМ;Where

- material gain at the FPM generation wavelength;

- потери на выход ФПМ;

- loss on the exit of the FPM;

α _i - internal optical loss associated with absorption on free charge carriers.

, на длине волны генерации λ_FP соответствует достаточно высокое значение потерь на межзонное поглощение в пассивных областях

. Как следствие, область распространения ФПМ ограничена только областью под полосковым омическим контактом 7. Из фиг.3 видно, что смещение в длинноволновую область спектра относительно длины волны генерации ФПМ одновременно ведет к снижению материального усиления в активной области 4 и падению значения оптических потерь (α_BGL) в боковых областях относительно полоскового омического контакта 7. Таким образом, вследствие нулевых потерь на выход для ЗМ даже в условиях меньшего значения материального усиления

на длине волны генерации для ЗМ может быть достигнут порог генерации. Рассмотрим пороговые условия генерации для ЗМ в инжекционном лазере с полосковым омическим контактом 7. Так как ЗМ захватывает весь объем волноводного слоя 1 инжекционного лазера, то фактор оптического ограничения ЗМ для области 9 усиления (Г_см) выглядит следующим образомTo determine the threshold condition for the ZM, it is necessary to evaluate the conditions of its propagation in the injection laser. Unlike the FPM, the electromagnetic waves of the SM propagate at angles greater than the angle of total internal reflection relative to the normal to the lateral limiting surfaces 10 and the Fabry-Perot cavity mirrors (5, 6). ZM is characterized by zero loss on the output of radiation from the resonator. In [S.O. Slipchenko, D. A. Vinokurov, A. V. Lyutetskiy, N. A. Pikhtin, A. L. Stankevich, N. V. Fetisova, A. D. Bondarev, I. S. Tarasov. - FTP, 43, 1409 (2009)] it was experimentally shown that, unlike the FPM, the ZM captures the entire volume of the injection laser, including the side parts relative to the strip contact 7. Figure 3 shows the qualitative dependences on the wavelength of the material gain in the amplification region 9 under the strip ohmic contact 7 (g _mat ) and from optical losses (α _BGL ) in the side regions relative to the strip ohmic contact 7. FPM with the maximum value of material gain

, at the generation wavelength λ _{FP there} corresponds a rather high value of the loss due to interband absorption in the passive regions

. As a result, the region of propagation of the FMP is limited only by the region under the strip ohmic contact 7. From Fig. 3 it can be seen that a shift to the long-wavelength region of the spectrum relative to the wavelength of the generation of the PCM simultaneously leads to a decrease in material gain in the active region 4 and a decrease in the value of optical losses (α _BGL ) in the lateral regions relative to the strip ohmic contact 7. Thus, due to zero output losses for the SM even under conditions of a lower value of material gain

at the generation wavelength for ZM, the generation threshold can be reached. Consider the threshold generation conditions for the ZM in the injection laser with a strip ohmic contact 7. Since the ZM captures the entire volume of the waveguide layer 1 of the injection laser, the optical limitation factor of the ZM for the amplification region 9 (G _cm ) is as follows

- значение составляющей фактора оптического ограничения Г_Y в области 9 усиления для ЗМ. Как показано выше (и подтверждено экспериментально), длина λ_см волны генерации ЗМ смещена в низкоэнергетическую область спектра относительно ФПМ. В результате материальное усиление ЗМ

может быть представлено как:Where

- the value of the constituent factor of the optical limitation G _Y in the amplification region 9 for ZM. As shown above (and confirmed experimentally), the length λ _cm of the ZM generation wave is shifted to the low-energy region of the spectrum relative to the MTF. As a result, material amplification of ZM

can be represented as:

where Δ is the detuning of material amplification, defined as the difference between the material amplifications of the FPM and ZM. Optical loss for 3M α _cm can be expressed as:

the quantity Δα takes into account losses associated with the scattering of ZM radiation by inhomogeneities, interband absorption, and absorption by free charge carriers in the side parts of the injection laser relative to the strip ohmic contact 7. Since the optical loss to the radiation output for ZM is zero, then in expression (9) they are not taken into account.

Based on the foregoing, the threshold conditions for ZM will take the form:

Taking the value Δ = 0, taking into account (3), we obtain an inequality, the satisfaction of which suppresses the generation of ZM in the injection laser:

. Увеличение потерь для ЗМ до величин, при которых выполняется указанное неравенство, позволяет подавить генерацию ЗМ в заявляемом инжекционном лазере. Требуемая для подавления генерации ЗМ величина внутренних оптических потерь в созданной области 13 подбирается путем выбора ее размеров и положения, решая волновое уравнение, что определяет значение

, а также выбора материала и его ширины запрещенной зоны, что определяет значение α_NB.At least one region 13 of semiconductor material created with at least one region 13 of semiconductor material with a band gap less than the band gap of the active region created at least in the waveguide layer 1 outside the injection region 8 can increase the optical loss for ZM by

. The increase in losses for ZM to values at which the specified inequality is satisfied, allows to suppress the generation of ZM in the inventive injection laser. The amount of internal optical loss required to suppress the generation of ZM in the created region 13 is selected by choosing its size and position, solving the wave equation, which determines the value

, as well as the choice of material and its band gap, which determines the value of α _NB .

The inventive injection laser operates as follows. An electric current is passed through the strip contact 7 of the proposed injection laser (see FIG. 2) in a direction perpendicular to the layers of the heterostructure, and the injection laser operating mode corresponds to the forward bias of the pn junction. When the current passed through the injection laser is exceeded by a threshold value through a naturally chipped face — mirror 5 with an antireflection coating — the Fabry-Perot mode laser radiation comes out. The output radiation power, in addition to the structure parameters, depends on the magnitude of the current transmitted through the laser heterostructure. Spontaneous emission on the closed-mode generation line is absorbed in the region 13 of the semiconductor material with a band gap less than the band gap of the active region 4 (see FIG. 2). This suppresses closed loop feedback. As a result, only the Fabry-Perot resonator modes are retained, which preserves the linearity of the dependence of the output power on the pump current and an increase in the output optical power.

Example. Comparative tests have been conducted of the known injection laser and the inventive injection laser. Injection was made known laser based heterostructure waveguide layer consisting of Al _0.3 Ga _0.7 As 1.6 micron sandwiched between a wide-emitter Al _0.5 Ga _0.5 As p-type conductivity and a thickness of 1.5 microns wide-emitter Al _0.5 Ga _0.5 As n a conductivity type with a thickness of 1.5 μm, an active region consisting of a single quantum-well active layer Al _0.08 Ga _0.92 As 12 nm thick, a Fabry-Perot optical resonator 2 mm long, formed naturally by a cleaved face with an antireflection coating having a reflection coefficient 5%, and g Anya coated with a reflective coating having a reflection coefficient of 95%, an ohmic contact strip 100 microns width, in the center between the side edges naturally cleaved by a distance of 500 microns, the substrate is GaAs n-type conductivity. For a well-known injection laser, the values of internal optical losses and radiation output loss for the Fabry-Perot resonator modes were 1 cm ^-1 and 7.6 cm ^-1 , respectively. An electric current is passed through the strip contact of a known injection laser (see FIG. 1) in a direction perpendicular to the layers of the heterostructure, and the operation mode of the injection laser (laser diode) corresponds to the forward bias of the pn junction. In the first version of the pump, a continuous current was passed; in the second version of the pump, a pulse current was passed with a current pulse duration of 100 ns and a frequency of 10 kHz. For a known injection laser, the dependence of the optical power exiting through the face coated with an antireflection coating on the continuous pump current is shown in Fig. 4 (curve 7); for a pulsed pump current, it is shown in Fig. 4 (curve 8). The output optical power reached its maximum value with a continuous pump current of 5 W and a pulsed pump current of 59.5 W.

,

,

значение составляющей фактора оптического ограничения Г_Y в области усиления для ЗМ

. Оптические потери Δα=1 см^-1. При выбранных параметрах введенной узкозонной области GaAs неравенствоThe inventive injection laser differed from the known injection laser in that one region of the GaAs semiconductor material was formed in the waveguide layer with a band gap of 1.43 eV, smaller than the band gap of the active region Al _0.08 Ga _0.92 As (1.55 eV). Optical losses associated with interband absorption of ZM radiation in the introduced region of the GaAs semiconductor material α _NB = 10 ⁴ cm ^-1 . The boundary of the introduced GaAs region closest to the injection region was located at a distance of 150 μm. The width of the GaAs region was 50 μm. Factors of optical limitation of ZM in the introduced GaAs region

,

,

the value of the component of the optical limiting factor Г _Y in the amplification region for ZM

. Optical loss Δα = 1 cm ^-1 . For the selected parameters of the introduced narrow-gap GaAs region, the inequality

performed. An electric current was passed through the strip contact of the inventive injection laser (see FIG. 2) in the direction perpendicular to the heterostructure layers, and the injection laser operating mode corresponded to the forward bias of the pn junction. In the first version of the pump, a continuous current was passed; in the second version of the pump, a pulse current was passed with a current pulse duration of 100 ns and a frequency of 10 kHz. For the inventive second embodiment of the injection laser, the dependence of the optical power exiting through the face with the antireflection coating on the continuous pump current is shown in Fig. 4 (curve 9), for a pulsed pump current it is shown in Fig. 4 (curve 10). The output optical power reached its maximum value with a continuous pump current of 10.5 W, and with a pulsed pump current of 77 W. The output optical power obtained for the inventive injection laser is higher than that of the known injection laser. Measurements of the output optical power over time showed that the temporal stability of the signal of the inventive injection laser is higher than that of the known injection laser. Thus, the inventive injection laser can increase the output optical power in a continuous and pulsed mode, and also has increased temporal stability of the output optical power.

Claims (13)

1. Injection laser based on a heterostructure containing a waveguide layer enclosed between wide-gap p- and n-type emitters, which are simultaneously boundary layers, an active region consisting of at least one quantum-dimensional active layer, an optical Fabry-Perot the resonator and the strip ohmic contact, under which the injection region is located, characterized in that at least one region of the semiconductor material is introduced into the waveguide layer outside the injection region bandgap smaller than the width of the forbidden band of the active region, the optical confinement factor of said closed-loop fashion semiconductor material satisfies the relationship:

Where

- the value of the component of the optical limiting factor G _X for ZM in the introduced region of the semiconductor material with a band gap less than the band gap of the active region, rel.

- the value of the constituent factor of the optical limitation G _Y for ZM in the introduced region of the semiconductor material with a band gap less than the band gap of the active region, rel.

- the value of the component of the optical limitation factor G _Z for ZM in the introduced region of the semiconductor material with the band gap less than the band gap of the active region, rel.
α _NB is the optical loss associated with interband absorption of ZM radiation in the introduced region of the semiconductor material with a band gap less than the band gap of the active region, cm ^-1 . 2. The injection laser according to claim 1, characterized in that the distance between the nearest boundaries of the region of said semiconductor material and the injection region is not less than 10 μm. 3. The injection laser according to claim 1, characterized in that the width of the region of said semiconductor material is not less than 10 μm. 4. The injection laser according to claim 1, characterized in that the band gap of the region of said semiconductor material is at least 20 meV less than the photon energy on the generation line of the injection laser. 5. The injection laser according to claim 1, characterized in that the region of said semiconductor material is made in the form of at least one quantum-dimensional layer. 6. The injection laser according to claim 1, characterized in that the region of said semiconductor material is made in the form of at least two quantum-dimensional layers with a different forbidden gap width. 7. The injection laser according to claim 1, characterized in that the region of said semiconductor material is made in the form of at least two quantum-well layers with different forbidden gap widths separated by a layer with a larger forbidden gap width. 8. The injection laser according to claim 1, characterized in that at least one region of said semiconductor material is introduced into each side part of the injection laser. 9. The injection laser according to claim 1, characterized in that the longitudinal size of the region of said semiconductor material is less than the length of the optical Fabry-Perot resonator. 10. The injection laser according to claim 1, characterized in that the heterostructure is made in the system of solid solutions A ³ B ⁵ . 11. The injection laser according to claim 1, characterized in that at least one boundary of the region of said semiconductor material is not parallel to the laterally naturally chipped faces forming the lateral boundary surfaces. 12. The injection laser according to claim 1, characterized in that the region of said semiconductor material is made of a doped n-type impurity selected from the group: Si, Te, Ge, Sn, or a combination thereof. 13. The injection laser according to claim 1, characterized in that the region of said semiconductor material is made of a doped p-type impurity selected from the group: C, S, Mg, Be, Zn, or a combination thereof.

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