CN103368056B - Multi-wave-length laser switching and outputting device - Google Patents

Abstract

The invention discloses a multi-wavelength laser switching output device, which includes: a fundamental-frequency laser source, which is used to generate fundamental-frequency light; a plurality of frequency-multiplying devices, which are used to generate multi-frequency-doubled light; Rotate the polarization direction of light under voltage control; a plurality of polarizers, which are used for high reflection of light in a predetermined polarization direction, and high transmission for light polarized perpendicular to the predetermined direction; an output window, which is used to output fundamental frequency light or Multiplied frequency light; wherein, by applying voltage or not applying voltage to one or more of the electro-optic devices, the output window outputs one of fundamental frequency light or multiplied frequency light. The above solution proposed by the present invention does not need to move the nonlinear crystal and the spectroscopic lens, but also can ensure that multiple wavelengths are output along the same output optical path and through the same light exit hole, and can output multi-wavelength lasers of each wavelength laser to the maximum Switch the output device.

Description

A multi-wavelength laser switching output device

technical field

The invention relates to the technical field of lasers, in particular to a multi-wavelength laser switching output device.

Background technique

With the rapid development of laser technology, various lasers have been widely used in industry, scientific research, national defense, medicine, entertainment and other fields. In these fields, there are higher requirements for the comprehensiveness of functions and the convenience of use of lasers. Lasers that output lasers of multiple wavelengths simultaneously or alternately are becoming the development target of many institutions because of their multiple application functions brought by multiple wavelengths.

In the existing technology, as shown in Figure 1, a traditional laser multi-wavelength output mode includes a fundamental frequency laser source 11, followed by a double frequency crystal 121 and a triple frequency crystal 122, a first beam splitter 131, The second beam splitter 132 and the laser absorber 14 , the second beam splitter 132 is placed on the reflected light path of the first beam splitter 131 , and other components are sequentially placed on the incident light axis of the laser light source 11 . During operation, the fundamental-frequency light emitted by the fundamental-frequency laser light source 11 is partially converted into double-frequency light and triple-frequency light through the nonlinear effect of the double-frequency crystal 121 and the triple-frequency crystal 122, and then passes through the first beam splitter 131 and the second beam splitter 132 to output triple frequency light, and the fundamental frequency laser and double frequency laser are incident into the laser absorber 14 . By analogy, by replacing the nonlinear crystal and the beam splitter, the fundamental frequency light and the double frequency light can be output respectively. The fundamental frequency light and the double and triple frequency light can be output separately along the same output light path and through the same light exit hole.

When the above-mentioned device performs wavelength switching, it not only needs to continuously replace various beam splitters by mechanical means, but also requires a precise mechanical translation device, and also needs to frequently move the nonlinear crystal into and out of the optical path. For example, if you want to output the fundamental frequency laser, you need to withdraw both the double frequency crystal and the triple frequency crystal from the optical path, and then replace the beam splitter for the triple frequency light with the beam splitter for the fundamental frequency light; and so on, if you need to output For double-frequency laser, the triple-frequency crystal needs to be withdrawn from the optical path, and then the triple-frequency beam splitter should be replaced with a double-frequency beam splitter. Since the frequency conversion efficiency of nonlinear crystals is usually sensitive to the horizontal and pitch angles, a very high-precision precision mechanical device is required to ensure that the crystal angle remains the same before and after the movement when the crystal moves into and out of the optical path. Otherwise, it will affect the frequency conversion efficiency of each crystal after reset, and this kind of extremely high-precision precision mechanical device is often very expensive and it is difficult to ensure the accuracy and stability of long-term work. Moreover, to complete so many moving in and out actions, many precision mechanical devices and control devices are required, which greatly increases the cost of the laser equipment and reduces the overall reliability of the equipment.

In the prior art, as shown in Figure 2, another traditional laser multi-wavelength output method includes a fundamental frequency laser source 21, followed by a double frequency crystal 221 and a frequency triple crystal 222, first and second splitters Mirrors 231, 232, the above components are sequentially placed on the incident optical axis of the laser light source 21, and the third beam splitter 233 and the fourth beam splitter 234 are respectively placed on the reflected light paths of the first beam splitter 231 and the second beam splitter 232. The first beam splitter 231 is highly reflective to triple-frequency light and highly transparent to fundamental-frequency light and double-frequency light; the second beam-splitter 232 is highly reflective to double-frequency light and highly transparent to fundamental frequency light. The third beam splitter 233 is highly reflective to triple frequency light; the fourth beam splitter 234 is highly reflective to double frequency light. When working, the beam splitting function of each beam splitter is used to simultaneously output the fundamental frequency light, the double frequency light and the triple frequency light. Each nonlinear crystal does not need to be frequently moved in and out of the optical path. However, the fundamental frequency light, double frequency light and triple frequency light are output along different optical axes and pass through three light outlets. This will be more troublesome when changing the output wavelength in actual use, and the entire external transmission and control optical path of the laser must be re-aligned and re-adjusted. At the same time, the obtained fundamental frequency light is the remaining laser light after undergoing double frequency and triple frequency transformation, and the obtained double frequency light is the remaining laser light after undergoing triple frequency transformation, and the power will be significantly higher than the initial state. Reduced, reducing the application range of the laser, which is not conducive to the multi-functional application of laser equipment.

Contents of the invention

The purpose of the present invention is to provide a multi-wavelength laser that does not need to move the nonlinear crystal and spectroscopic lens, but also can ensure that multiple wavelengths are output along the same output optical path and through the same light exit hole, and can output each wavelength laser to the maximum. Wavelength laser switching output device.

For this reason, the present invention proposes a kind of multi-wavelength laser switching output device, which comprises:

a fundamental frequency laser source for generating fundamental frequency light;

a plurality of frequency doubling devices for generating multiplied frequency light;

a plurality of electro-optic devices that rotate the polarization of light under voltage control;

A plurality of polarizers, which are used for high reflection of light in a predetermined polarization direction, and high transmission of light polarized perpendicular to the predetermined direction; an output window, which is used to output fundamental frequency light or multiplied frequency light;

Wherein, by applying voltage or not applying voltage to one or more of the electro-optic devices, the output window outputs one of fundamental frequency light or multiplied frequency light.

The beneficial effect of the present invention is to provide a laser beam that does not need to move the nonlinear crystal and spectroscopic lens, but also can ensure that multiple wavelengths are output along the same output optical path and through the same light exit hole, and can output each wavelength of laser light to the maximum. Multi-wavelength laser switching output device. The multi-wavelength laser does not need to use extremely high-precision precision mechanical devices in practical applications, which greatly reduces the difficulty and cost of manufacturing; it does not need to re-align and adjust the external transmission control optical path, and can be easily switched at any time and fully Laser output of each wavelength is used in various working states and conditions.

Description of drawings

Fig. 1 is a structural schematic diagram of a multi-wavelength laser output mode in the prior art;

FIG. 2 is a structural schematic diagram of another multi-wavelength laser output mode in the prior art;

FIG. 3 is a schematic structural diagram of a multi-wavelength laser switching output device of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

Fig. 3 shows a structure diagram of a multi-wavelength laser switching output device proposed by the present invention. As shown in Figure 3, the multi-wavelength laser switching output device includes:

A fundamental frequency laser source 31, which is used to obtain the linearly polarized fundamental frequency light whose polarization direction is along the horizontal direction (parallel to the paper and perpendicular to the light), and the wavelength of the fundamental frequency light is 1064nm;

The first electro-optic device 321, which is used to rotate the polarization direction of the linearly polarized fundamental frequency light, contains electro-optic crystal KDP (potassium dihydrogen phosphate), and the surfaces of the two light channels are all plated to 1064nm fundamental frequency light. The high-transmittance film layer is controlled by the external drive source of the machine by applying a voltage to the crystal (not shown in the figure). By applying a certain voltage, the polarization direction of the incident linearly polarized 1064nm fundamental frequency light can be rotated by 90°;

For the first polarizer 331, the second polarizer 332, and the third polarizer 333 that polarize the linearly polarized fundamental frequency 1064nm light, the linear polarization of the three polarizers is along the vertical direction (perpendicular to the paper surface) High reflection of 1064nm light, high transmission of linearly polarized 1064nm light whose polarization direction is along the horizontal direction (parallel to the paper surface and perpendicular to the light);

The first beam splitter 351 is highly reflective for light with a fundamental frequency of 1064nm;

The frequency doubling device 341 for generating double frequency 532nm laser, which generates double frequency light after receiving the fundamental frequency light, adopts non-critical type I phase-matched LBO (lithium triborate) crystal, and the surface of the two passes is plated The base frequency 1064nm, double frequency 532nm laser high transmittance film layer.

The second electro-optic device 322, which plays the role of rotating polarization for the remaining linearly polarized fundamental frequency light after passing through the double frequency device 341, contains electro-optic crystal KDP (potassium dihydrogen phosphate), and the two optical surfaces are plated on the base The high-transmittance film layer of the 1064nm laser frequency is controlled by the external drive source of the machine by applying a voltage to the crystal (not shown in the figure). By applying a certain voltage, the remaining linearly polarized radicals after passing through the double frequency device 341 can be made The polarization direction of the frequency 1064nm laser is rotated by 90°;

The second beam splitter 352 and the third beam splitter 353, which are highly reflective for fundamental frequency 1064nm light;

The fourth beam splitter 354 and the fifth beam splitter 355, which are highly reflective for the fundamental frequency 1064nm light; high transmittance for the double frequency 532nm light;

The frequency-tripling device 342 for generating triple-frequency 355nm laser, which generates triple-frequency light after receiving the fundamental frequency light and the double-frequency light, uses a critical type II phase-matched LBO (lithium triborate) crystal, The surface of the two-pass light is plated with a high-transmittance film layer of fundamental frequency 1064nm, double frequency 532nm, and triple frequency 355nm;

The sixth beamsplitter 356 is highly reflective for light with a fundamental frequency of 1064nm and light with a double frequency of 532nm, and high transmittance for light with a triple frequency of 355nm;

The third electro-optic device 323, which plays the role of rotating polarization for the double frequency 532nm light, contains electro-optic crystal KDP (potassium dihydrogen phosphate), and the surfaces of the two light passes are coated with a high-transmittance film layer for the double frequency 532nm laser. , the external drive source of the machine is controlled by applying a voltage to the crystal (not shown in the figure), and by applying a certain voltage, the polarization direction of the incident linearly polarized double-frequency 532nm laser can be rotated by 90°;

For the fourth polarizer 334 that polarizes the double frequency 532nm light, this polarizer is highly reflective to the linearly polarized 532nm light whose polarization direction is along the vertical direction (perpendicular to the paper surface), and along the horizontal direction (parallel to the paper surface) to the polarization direction. High transmission of linearly polarized double frequency 532nm light on the paper surface and perpendicular to the light;

The seventh beam splitter 357 is highly reflective for double frequency 532nm light and highly transparent for fundamental frequency 1064nm light;

The eighth beam splitter 358 is highly reflective for double frequency 532nm light;

The ninth beam splitter 359 is highly reflective for double frequency 532nm light, and highly transparent for fundamental frequency 1064nm light and triple frequency 355nm light;

The first absorber 361 is used to receive the fundamental frequency 1064nm light reflected by the third polarizer 333;

The second absorber 362 is used to receive the fundamental frequency 1064nm light transmitted by the seventh beam splitter 357;

The third absorber 363 is used to receive the double frequency 532nm light reflected by the fourth polarizer 334; these three absorbers are used to absorb the remaining laser light to avoid danger caused by laser leakage.

The window 37 , from which lasers of various wavelengths are finally output, the window has high transmittance to lasers with a fundamental frequency of 1064nm, a doubled frequency of 532nm, and a tripled frequency of 355nm.

Among the above multiple devices, the first electro-optic device 321, the first polarizer 331, the double frequency device 341, the fourth beam splitter 354, the fifth beam splitter 355, the triple frequency device 342, the sixth beam splitter 356, the ninth The beam splitter 359 and the window plate 37 are sequentially placed on the light path of the fundamental frequency laser source 31; the second polarizer 332 is placed on the reflected light path of the first polarizer 331; the first beam splitter 351 is placed on the The reflection light path of the second polarizer 332, and the reflection light path of the first beam splitter 351 is incident on the sixth beam splitter 356; the second beam splitter 352 is placed on the reflection light path of the fourth beam splitter 354 , the second electro-optic device 322 is placed on the reflected light path of the second beam splitter 352; the third polarizer 333 is placed on the outgoing light path of the second electro-optic device 322; the first absorber 361 is located on the third polarization The reflected optical path of the sheet 333; the third beam splitter 353 is placed on the transmitted optical path of the third polarizer 333, and its reflected optical path is incident on the fifth beam splitter 355; the sixth beam splitter 356 and the The seventh beam splitter 357 is sequentially located on the reflected light path of the first beam splitter 351; the second absorber 362 is located on the transmitted light path of the seventh beam splitter 357; the third electro-optic device 323 is located on the seventh beam splitter On the reflective optical path of the mirror 357, the fourth polarizer 334 is located on the outgoing optical path of the third electro-optic device, and the third absorber 363 is located on the reflective optical path of the fourth polarizer 334; the eighth The beam splitter 358 is located on the transmitted light path of the fourth polarizer 334 , and its reflected light path is incident on the ninth beam splitter 359 .

Using the device of the present invention, the method for realizing multi-wavelength laser switching output is as follows:

According to the structure in the above content, each device is placed in sequence, and no voltage is applied to the first, second, and third electro-optical devices 321, 322, and 323, so that the incident linearly polarized fundamental frequency 1064nm light and the doubled frequency are not changed. The polarization direction of the 532nm laser. Turn on the laser source 31 at this time, then the fundamental frequency 1064nm laser with the polarization direction of its emission along the horizontal direction (parallel to the paper surface and perpendicular to the light) passes through the first polarizer 331 and then enters the double frequency device 341 to obtain the polarization direction along the horizontal direction. Double frequency 532nm laser in the vertical direction (perpendicular to the paper). At this time, the remaining light with a fundamental frequency of 1064nm is highly reflected by the fourth beam splitter 354 and the second beam splitter 352, passes through the second electro-optic device 322, is highly transmitted by the third polarizer 333, and then passes through the third beam splitter 353 and the fifth beam splitter. The beam splitter 355 enters the triple frequency device 342 after high reflection, and the double frequency 532nm laser also enters the triple frequency device 342 after being highly transmitted by the fourth beam splitter 354 and the fifth beam splitter 355, and the fundamental frequency 1064nm light and the double frequency The 532nm light generates triple frequency 355nm light in the triple frequency device 342, after passing through the sixth beam splitter 356 and the ninth beam splitter 359, it exits through the window plate 37, and the remaining fundamental frequency after passing through the triple frequency device 342 The 1064nm light enters the second absorber 362 through the sixth beamsplitter 356 with high reflection and the seventh beamsplitter 357 with high transmission, and the remaining double-frequency 532nm light is highly reflected by the sixth beamsplitter 356 and the seventh beamsplitter 357, and then passes through The third electro-optical device 323 is highly reflected by the fourth polarizer 334 and enters the third absorber 363 , so the output from the window 37 is pure tripled frequency 355nm light.

Through an external driving source, a voltage is applied to the second electro-optic device 322 to rotate the polarization direction of the passing fundamental frequency 1064nm laser by 90° into a vertical direction (perpendicular to the paper), and a voltage is applied to the third electro-optic device 323. Voltage, rotate the polarization direction of the passing double frequency 532nm laser by 90° to be along the horizontal direction (parallel to the paper surface and perpendicular to the light), at this time, the remaining fundamental frequency 1064nm light after passing through the double frequency device 341 passes through the second electro-optic After the device 322, it is highly reflected by the third polarizer 333 and enters the first absorber 361. The generated double frequency 532nm light alone passes through the triple frequency device 342 without frequency conversion. After passing through the high transmission, it passes through the sixth beam splitter 356 and the second After being highly reflected by the seven beamsplitters 357, the polarization direction is rotated by the third electro-optic device 323 and then highly transmitted by the fourth polarizer 334. After being highly reflected by the eighth beamsplitter 358 and the ninth beamsplitter 359, it exits through the window plate 37, and finally from the What the window plate 37 outputs is pure double frequency 532nm light.

Through the driving source outside the laser, a voltage is applied to the first electro-optic device 321, so that it rotates the polarization direction of the passing fundamental frequency 1064nm laser by 90° to become along the vertical direction (perpendicular to the paper surface), then the emitted fundamental frequency The 1064nm laser is highly reflected by the first polarizer 331, then highly reflected by the second polarizer 332, the first beam splitter 351, and the sixth beam splitter 356, and highly transmitted by the ninth beam splitter 359, and output through the window 37, thereby From this device, a pure fundamental frequency 1064nm laser output is obtained;

For the first beamsplitter 351, the second beamsplitter 352, the third beamsplitter 353, the fourth beamsplitter 354, the fifth beamsplitter 355, the sixth beamsplitter 356, the seventh beamsplitter 357, and the eighth beamsplitter The incident angles of the mirror surfaces of 358 and 9th beam splitter 359 are both 45°, and the high-transmission and high-reflection coatings plated on the mirror surfaces of each beam splitter are based on the premise that the light incident angle is 45°.

The above three working modes can conveniently switch between the wavelengths by controlling the external driving source of the laser in real time, without moving any nonlinear crystals and spectroscopic lenses, and can ensure that multiple wavelengths pass through the same output optical path. Output from the same light hole, and can output each wavelength of laser light to the maximum.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the present invention.

Claims (5)

1. multiwavelength laser switches an output device, and it comprises:

Basic frequency laser source, it is for generation of fundamental frequency light;

Multiple frequency doubling device, it is for generation of multiple frequence light; Described multiple frequency doubling device comprises two frequency doubling devices and frequency tripling device;

Multiple electro-optical device, it rotates polarisation of light direction under voltage control; Described multiple electro-optical device comprises the first electro-optical device, the second electro-optical device and the 3rd electro-optical device;

Multiple polarizer, it is for the light high reverse--bias to predetermined polarisation direction, to the light height transmission perpendicular to predetermined direction polarization; An output window, it is for exporting fundamental frequency light or multiple frequence light; Described multiple polarizer comprises the first polarizer, the second polarizer, the 3rd polarizer and the 4th polarizer;

Multiple spectroscope, for fundamental frequency light or multiple frequence light high reverse--bias or high transmission; Described multiple spectroscope comprises the first spectroscope, the second spectroscope, the 3rd spectroscope, the 4th spectroscope, the 5th spectroscope, the 6th spectroscope, the 7th spectroscope, the 8th spectroscope and the 9th spectroscope;

Three absorbers, i.e. the first absorber, the second absorber and the 3rd absorber, it is respectively used to, when exporting fundamental frequency light or multiple frequence light, absorb unnecessary fundamental frequency light or multiple frequence light;

Wherein, by applying voltage to wherein one or more electro-optical devices described or not applying voltage, the one in output window output fundamental frequency light or multiple frequence light is made;

Wherein, described first electro-optical device, the first polarizer, two frequency doubling devices, the 4th spectroscope, the 5th spectroscope, frequency tripling device, the 6th spectroscope, the 9th spectroscope and diaphragm are placed in the light path of described basic frequency laser source bright dipping successively; Second polarizer is positioned on the reflected light path of described first polarizer; Described first spectroscope is placed on the reflected light path of described second polarizer, and first spectroscopical reflected light path is incident on the 6th spectroscope; Described second spectroscope is placed on described 4th spectroscopical reflected light path, and the second electro-optical device is positioned on described second spectroscopical reflected light path; 3rd polarizer is positioned on the emitting light path of described second electro-optical device; First absorber is positioned on the reflected light path of described 3rd polarizer; Described 3rd spectroscope is positioned on the transmitted light path of described 3rd polarizer, and its reflected light path is incident to the 5th spectroscope; Described 6th spectroscope and the 7th spectroscope are positioned on first spectroscopical reflected light path successively; Described second absorber is positioned on described 7th spectroscopical transmitted light path; Described 3rd electro-optical device is positioned on described 7th spectroscopical reflected light path, and described 4th polarizer is positioned on the emitting light path of described 3rd electro-optical device, and described 3rd absorber is positioned on the reflected light path of described 4th polarizer; Described 8th spectroscope is positioned on the transmitted light path of the 4th polarizer, and its reflected light path is incident on the 9th spectroscope, and the 9th spectroscope is positioned on described first spectroscopical reflected light path.

2. multiwavelength laser as claimed in claim 1 switches output device, it is characterized in that, described multiple polarizer is used for polarization direction light high reverse--bias vertically, to polarization direction light height transmission in the horizontal direction.

3. multiwavelength laser as claimed in claim 1 switches output device, it is characterized in that, multiwavelength laser switches output device for exporting fundamental frequency light, two frequency doubled lights and frequency tripling light.

4. multiwavelength laser as claimed in claim 3 switches output device, it is characterized in that, when described multiwavelength laser switches output device for exporting fundamental frequency light, described first electro-optical device applies voltage, and the second electro-optical device and the 3rd electro-optical device do not apply voltage; Described multiwavelength laser switches output device for exporting two frequency doubled lights, and wherein the first electro-optical device does not apply voltage, and the second electro-optical device and the 3rd electro-optical device apply voltage; When described multiwavelength laser switches output device for exporting frequency tripling light, three electro-optical devices all do not apply voltage.

5. multiwavelength laser switches an output intent, and it comprises:

When step 1, output fundamental frequency light, apply voltage to the first electro-optical device; The fundamental frequency light that fundamental frequency light source produces is incident to the first electro-optical device, first electro-optical device rotates the polarization direction of described fundamental frequency light, through the postrotational fundamental frequency light in polarization direction by after the first polarizer and the second polarizer high reverse--bias, be incident to the first spectroscope, described fundamental frequency light, is exported from output window by the first spectroscope and the 6th dichroic mirror again after the 9th spectroscope transmission;

Step 2, when exporting two frequency doubled lights, the first electro-optical device does not apply voltage, and second, third electro-optical device applies voltage; The fundamental frequency light that fundamental frequency light source produces exports through the first electro-optical device, the fundamental frequency light exported enters two frequency doubling devices after the first polarizer transmission, and export two frequency doubled lights, two frequency doubled lights enter frequency tripling device through the 4th spectroscope and the 5th spectroscope, after the 4th spectroscope and the second dichroic mirror, enter the second electro-optical device through the remaining fundamental frequency light of two frequency doubling devices simultaneously, second electro-optical device rotates its polarization direction, and through polarization direction, postrotational fundamental frequency light is entered the first absorber absorb by the 3rd polarizer reflection; Two frequency doubled lights entering separately frequency tripling device do not produce frequency inverted and directly export, after the 6th spectroscope and the 7th dichroic mirror, again behind the 3rd electro-optical device rotatory polarization direction by the 4th polarizer height transmission, then by output window outgoing after the 8th spectroscope and the 9th dichroic mirror;

When step 3, output frequency tripling light, described first electro-optical device, the second electro-optical device and the 3rd electro-optical device all do not apply voltage, the fundamental frequency light that fundamental frequency light source produces exports through the first electro-optical device, the fundamental frequency light exported enters two frequency doubling devices after the first polarizer transmission, and export two frequency doubled lights, two frequency doubled lights enter frequency tripling device through the 4th spectroscope and the 5th spectroscope, after the 4th spectroscope and the second dichroic mirror, enter the second electro-optical device through the remaining fundamental frequency light of two frequency doubling devices simultaneously, frequency tripling device is entered through the 3rd spectroscope and the 5th dichroic mirror again after the 3rd polarizer transmission, frequency tripling device produces frequency tripling light based on the fundamental frequency light and two frequency doubled lights entering it, and export through output window after the 6th spectroscope and the 9th spectroscope transmission, remaining fundamental frequency light after frequency tripling device simultaneously, absorb via entering the second absorber after the 6th dichroic mirror, the 7th spectroscope transmission, remaining two frequency doubled lights, via after the 6th spectroscope and the 7th dichroic mirror, are entered the 3rd absorber by the 4th polarizer reflection and absorb after the 3rd electro-optical device.