Tunable dual-wavelength laser output device

Abstract

The invention discloses a tunable dual-wavelength laser output device, and belongs to the technical field of semiconductor laser. According to the tunable dual-wavelength laser output device, a light beam fast and slow axis collimation system converts a light beam emitted by a blue laser single tube into collimated light; the dual-wavelength light splitting wide compression system comprises two light beam reflectors, two beam expanding subsystems, a transmission grating and two plane reflectors. A part of collimated light intercepted by the light beam reflecting mirror enters the beam expanding subsystem, and the remaining collimated light enters the laser output characteristic measuring system; the transmission grating diffracts the expanded light beam and outputs the light beam to the plane mirror; the plane mirror reflects the vertically incident laser to enable the laser to return along an original light path so as to enable the blue laser single tube to output two kinds of laser with specific wavelengths; the controller adjusts the angle of the plane mirror so as to enable the plane mirror to reflect laser with different wavelengths; the laser output characteristic measurement system measures the output power and spectral characteristics of the two lasers with different wavelengths; the controller draws a gain spectrum of a laser working band.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor lasers, and more specifically, relates to a tunable dual-wavelength laser output device. Background Art

[0002] Dual-wavelength laser light sources play an important role in precision measurement, spectroscopy and cutting-edge optical research, and can be used for interferometry, nonlinear frequency conversion, generation of coherent radiation in the mid-infrared and terahertz bands, etc. These applications not only promote the progress of scientific research, but also bring about the practical application of many new technologies, covering various fields from basic research to industrial production.

[0003] In interferometry, especially in eliminating phase ambiguity and improving measurement accuracy, using dual-wavelength lasers, the interferometer can accurately calculate the optical path difference by measuring the phase difference between the two wavelengths of light in the target and reference paths. Interference signals of different wavelengths can be used in combination to improve the resolution and range of the measurement. In the nonlinear optical process, two wavelengths of laser can interact in a nonlinear medium to generate mid-infrared photons corresponding to their frequency difference. Terahertz radiation has important applications in imaging, communications, security scanning, and material analysis. Coherent radiation in the terahertz band can be generated by the difference frequency or sum frequency process of two wavelengths of laser in nonlinear materials. Through dual-wavelength laser excitation, nonlinear crystals can produce broadband mid-infrared spectra, which are widely used in laser spectroscopy, medical imaging, chemical sensing and other fields.

[0004] In coherent control and photon modulation, dual-wavelength laser sources can be used to generate and manipulate quantum states, such as entangled states or superradiant states. The control of these quantum states has important applications in quantum computing, quantum communication, and quantum sensing. In ultrafast laser systems, dual-wavelength lasers can be used to generate and control ultrashort pulses of laser light, which are used in ultrafast dynamics research, time-resolved spectroscopy, and materials science.

[0005] The linewidth requirements of dual-wavelength lasers usually depend on the specific application, but usually narrow linewidth is preferred to ensure high coherence, improve measurement accuracy, increase nonlinear frequency conversion efficiency, and improve signal quality. In some high-precision applications, such as spectroscopy or quantum optics, lasers may require ultra-narrow linewidth to meet stringent performance requirements.

[0006] Dual-wavelength laser light sources rely on precise wavelength selection and tuning, and the gain spectrum directly affects the output power and wavelength stability of the laser. Complete gain spectrum acquisition plays a key role in applications that require precise gain matching during nonlinear frequency conversion. The traditional method of generating dual-wavelength lasers is to generate two lasers with different wavelengths by pumping a semiconductor laser into a crystal. It can be divided into achieving dual-wavelength output by using a single crystal to use the reflectivity difference of the output mirror for different wavelengths; outputting different wavelength lasers through dual crystals; and achieving dual-wavelength output through an optical parametric oscillator.

[0007] In the above method, when dual lasers with similar output wavelengths are used, the regulation is more complicated. Since crystals are used, the pump light requirements are high, and when dual-wavelength lasers are output through crystals, the laser line width is usually wider without control, which is not conducive to precision applications. Summary of the invention

[0008] In view of the defects of the related art, the purpose of the present invention is to provide a tunable dual-wavelength laser output device, which aims to solve the problems that when a dual-wavelength laser outputs dual lasers with similar wavelengths, the regulation is more complicated, the requirements for pump light are higher, and the laser line width is wider, and the resulting problem of difficulty in obtaining a complete gain spectrum of the laser light source.

[0009] To achieve the above-mentioned object, the present invention provides a tunable dual-wavelength laser output device, comprising: a blue laser single tube, a beam fast and slow axis collimation system, a dual-wavelength splitting beam width compression system, a laser output characteristic measurement system and a controller;

[0010] The light beam fast and slow axis collimation system is used to convert the light beam emitted by the blue laser single tube into collimated light;

[0011] The dual-wavelength spectroscopic line width compression system comprises two beam reflectors, two beam expansion subsystems, a transmission grating and two plane reflectors; each of the beam reflectors is used to intercept a portion of collimated light and enter the corresponding beam expansion subsystem for beam expansion, and the remaining collimated light enters the laser output characteristic measurement system; the transmission grating is used to diffract the beam after beam expansion and then output it to the plane reflector; the two plane reflectors are used to reflect the vertically incident laser light and return it to the blue laser single tube along the original optical path, so that the blue laser single tube outputs two specific wavelength lasers;

[0012] The controller is connected to the plane reflector and is used to adjust the angle of the plane reflector so as to make it reflect laser beams of different wavelengths output by the transmission grating;

[0013] The laser output characteristic measurement system is used to measure the output power and spectral characteristics of two lasers with different wavelengths;

[0014] The controller is also connected to the laser output characteristic measurement system and is used to draw the gain spectrum of the blue laser single tube in the working band according to the output power and spectral characteristics of different wavelengths obtained by the laser output characteristic measurement system.

[0015] Optionally, the two beam reflectors are arranged on both sides of the collimated light entering the laser output characteristic measurement system, and are used to intercept the edge beams of the collimated light output by the beam fast and slow axis collimation system for wavelength locking and line width compression.

[0016] Optionally, the reflecting surface of the beam reflector is 45° to the incident light, and is used to deflect the incident laser by 90°.

[0017] Optionally, the controller is also connected to the beam reflector to control the movement of the beam reflector to change the proportion of intercepting the laser beam.

[0018] Optionally, the beam reflector is one of a triangular prism, a plane reflector, a dielectric film reflector, a super reflector, a laser line reflector, and an elliptical reflector.

[0019] Optionally, the light beam fast and slow axis collimation system includes an aspherical cylindrical lens and a plano-convex cylindrical lens;

[0020] The aspherical cylindrical lens is a fast axis collimator, which is used to collimate the fast axis of the blue laser single tube;

[0021] The plano-convex cylindrical lens is a slow-axis collimator, the curved surface direction of which is perpendicular to the aspherical cylindrical lens, and is used to collimate the slow axis of the blue laser single tube.

[0022] Optionally, the beam expansion subsystem includes a lens pair consisting of a plano-concave spherical lens and a plano-convex spherical lens;

[0023] The focal points of the plano-concave spherical lens and the plano-convex spherical lens overlap, and the focal length of the plano-convex spherical lens is greater than the absolute value of the focal length of the plano-concave spherical lens.

[0024] Optionally, the tunable dual-wavelength laser output device further includes an optical path deflection reflector for converging two paths of laser light onto the same transmission grating.

[0025] Optionally, the laser output characteristic measurement system includes a plane spectroscope, a spectrometer and a power meter;

[0026] The plane beam splitter is 45° to the incident light;

[0027] The spectrometer is placed at the right end of the plane beam splitter to receive reflected light and detect the wavelength and line width of the output light beam;

[0028] The power meter is placed at the lower end of the plane beam splitter and is perpendicular to the transmitted light, and is used to detect the power of the received light beam.

[0029] Compared with the prior art, the above technical solution conceived by the present invention can achieve the following beneficial effects:

[0030] 1. The present invention provides a tunable dual-wavelength laser output device, which intercepts a beam and divides it into three parts through a beam reflector, wherein the intercepted two beams are selected by a transmission grating for a specific wavelength laser, and then selectively reflect different wavelength lasers back to the blue laser single tube through a plane reflector to obtain a competitive advantage, thereby realizing a laser single tube outputting high-power lasers of this wavelength. By precisely controlling the angle of the reflector behind the grating, the laser can provide a stable dual-wavelength output, realize the tunability of the output dual wavelength, and the adjustment operation is simple, the requirements for the laser source are low, and the beam has a narrow line width. The problem that the dual-wavelength laser outputs dual lasers with similar wavelengths is that the regulation is more complicated, the pump light requirements are higher, and the laser line width is wider. It can flexibly adapt to different application requirements and maintain high performance under different environmental conditions. At the same time, the laser output characteristic measurement system measures the output power and spectral characteristics of two lasers with different wavelengths. The controller continuously changes the output laser wavelength, and the gain spectrum of the laser in the working band can be drawn, thereby solving the problem that it is difficult to obtain the complete gain spectrum of the laser light source due to complex wavelength tuning. The tunable dual-wavelength laser output device of the present invention can realize dual-wavelength laser output with a tunable narrow linewidth gain spectrum and a complete spectrum.

[0031] 2. The present invention provides a tunable dual-wavelength laser output device, which controls the plane reflector to achieve wavelength tuning through a controller, and controls the power meter to achieve power monitoring. The laser output device can not only output tunable wavelengths, but also measure gain spectra at different wavelengths. It can monitor the gain characteristics of the laser output device in real time, optimize the power and coherence of the laser output, and meet the needs of specific applications to ensure that the highest efficiency laser output can be achieved at different wavelengths. For dual-wavelength lasers, mastering the gain spectrum can help adjust the power balance and coherence between the two wavelengths.

[0032] 3. The present invention provides a tunable dual-wavelength laser output device, which integrates optical components such as gratings and reflectors inside the laser output device, reducing the system volume and improving the overall stability. Compared with the traditional method of using pump crystals, it is easy to adjust the wavelength and measure the gain spectrum, suitable for use in various experimental environments, without the need for complex calibration and adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a tunable dual-wavelength laser output device provided by the present invention;

[0034] Figure 2 is a structural schematic diagram of the slow axis of the collimation system provided by the present invention;

[0035] Figure 3 It is a structural schematic diagram of the fast axis of the collimation system provided by the present invention;

[0036] Figure 4 is a schematic diagram of the light splitting structure provided by the present invention;

[0037] Figure 5 It is a schematic diagram of the first optical path of the dual-wavelength splitting optical bandwidth compression system provided by the present invention;

[0038] Figure 6 It is a schematic diagram of the second optical path of the dual-wavelength splitting optical bandwidth compression system provided by the present invention;

[0039] Figure 7 It is a schematic diagram of the laser output characteristic measurement system provided by the present invention.

[0040] The reference numerals in the above figures are the same, and the reference numerals in the figures are: 1. blue light laser single tube, 2. aspheric cylindrical lens, 3. plano-convex cylindrical lens, 4. first triangular prism, 5. third plane reflector, 6. first plano-concave spherical lens, 7. first plano-convex spherical lens, 8. transmission grating, 9. first plane reflector, 10. second triangular prism, 11. second plano-concave spherical lens, 12. second plano-convex spherical lens, 13. second plane reflector, 14. plane beam splitter, 15. spectrometer, 16. power meter. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] The contents involved in the above embodiment are described below in conjunction with a preferred embodiment.

[0043] A tunable dual-wavelength laser output device, comprising: a blue laser single tube 1, a beam fast and slow axis collimation system, a dual-wavelength splitting line width compression system, a laser output characteristic measurement system and a controller (not shown);

[0044] The light beam fast and slow axis collimation system is used to convert the light beam emitted by the blue laser single tube 1 into collimated light;

[0045] The dual-wavelength spectroscopic line width compression system comprises two beam reflectors, two beam expansion subsystems, a transmission grating 8 and two plane reflectors; each of the beam reflectors is used to intercept a portion of the collimated light and enter the corresponding beam expansion subsystem for beam expansion, and the remaining collimated light enters the laser output characteristic measurement system; the transmission grating 8 diffracts the beam after beam expansion and then outputs it to the plane reflector; the two plane reflectors are used to reflect the vertically incident laser light and return it to the blue laser single tube 1 along the original optical path, so that the blue laser single tube 1 outputs two specific wavelength lasers;

[0046] The controller is connected to the plane reflector and is used to adjust the angle of the plane reflector so as to make it reflect lasers of different wavelengths output by the transmission grating 8;

[0047] The laser output characteristic measurement system is used to measure the output power and spectral characteristics of two lasers with different wavelengths;

[0048] The controller is also connected to the laser output characteristic measurement system and is used to draw the gain spectrum of the blue laser single tube in the working band according to the output power and spectral characteristics of different wavelengths obtained by the laser output characteristic measurement system.

[0049] like Figure 1 , Figure 4 As shown, as the first step of dual-wavelength splitting linewidth compression, the collimated light beam needs to be split for processing. The laser outputted by the blue laser single tube 1 is collimated by the beam fast and slow axis collimation system, and then divided into three beams by the first beam reflector 4 and the second beam reflector 10. The left and right beams are reflected as the input light of the dual-wavelength linewidth compression system. The first beam enters the first beam expansion subsystem and is expanded and then emitted to the transmission grating 8. The second beam enters the second beam expansion subsystem and is also expanded and then emitted to the transmission grating 8. It is output after diffraction. Since the diffraction angles of different wavelengths passing through the transmission grating 8 are different, the first plane reflector 9 and the second plane reflector 13 arranged behind the transmission grating 8 only reflect the vertically incident laser of a specific wavelength. The angles of the first plane reflector 9 and the second plane reflector 13 are rotated by the controller to make them perpendicular to the desired laser of different wavelengths after passing through the transmission grating 8, so that the laser of this wavelength obtains a competitive advantage in the external cavity, thereby making the blue laser single tube 1 output high-power laser of this wavelength. The laser output from the blue laser tube 1 is lasers of two specific wavelengths, and the laser output characteristic measurement system measures the output power and spectral characteristics of the two lasers of different wavelengths. The tunable dual-wavelength laser output device provided in this embodiment realizes tunable dual-wavelength output, and the coherence between the two wavelengths can be controlled by precisely adjusting the wavelength. This is crucial for interferometry, phase-sensitive applications, and multi-wavelength coherent detection systems.

[0050] At the same time, the laser output characteristic measurement system of the scheme of the present invention measures the output power and spectral characteristics of two different wavelength lasers of the laser output device. Since the laser output device has different gains for different wavelengths, when the beam reflector is fixed, that is, the intercepted light ratio remains unchanged, the angle of the plane reflector is changed by the controller to continuously change the output laser wavelength, and the gain spectrum of the laser in the working band can be drawn according to the output power and spectral characteristics of different wavelengths, thereby solving the problem of difficulty in obtaining the complete gain spectrum of the laser light source due to complex wavelength tuning. The tunable dual-wavelength laser output device of this scheme can achieve dual-wavelength laser output with a complete tunable narrow linewidth gain spectrum.

[0051] Among them, the blue laser tube 1 is an uncollimated edge-emitting blue semiconductor laser tube, with a rated output wavelength of 445nm, a fast axis divergence half angle of 22.5°, a light emission length of 1μm, a slow axis divergence half angle of 4°, and a light emission length of 50μm. According to the basic characteristics of semiconductor laser diodes, its fast axis is a single transverse mode output, and its slow axis is a multi-longitudinal mode output. Since the diode is prone to heat during normal operation, the temperature affects the output wavelength and power of the laser during operation, so it needs to be cooled to stabilize its working state so as not to affect the output state and add irrelevant variables in the gain spectrum measurement.

[0052] The grating in this embodiment is a transmission grating, which has high optical transparency and high refractive efficiency, plays a good transmission and diffraction role in the optical path, and can separate lasers of different wavelengths with low loss.

[0053] Optionally, the two beam reflectors are arranged on both sides of the collimated light entering the laser output characteristic measurement system, and are used to intercept the edge beams of the collimated light output by the beam fast and slow axis collimation system for wavelength locking and line width compression.

[0054] Optionally, the controller is also connected to the beam reflector to control the movement of the beam reflector to change the proportion of intercepting the laser beam.

[0055] The light beam incident on the first beam reflector 4 is defined as the first beam, the light beam incident on the second beam reflector 10 is defined as the second beam, and the light beam entering the laser output characteristic measurement system is defined as the third beam; the first beam reflector 4 and the second beam reflector 10 can be arranged on the same side or on both sides of the third beam.

[0056] like Figure 1 As shown, the first beam reflector 4 and the second beam reflector 10 are symmetrically distributed on both sides of the third beam, intercepting the edge beam for wavelength locking and line width compression, and using the middle beam with higher intensity for output. Compared with the structure where two prisms are located on the same side of the beam, the lenses distributed on both sides can move independently to change the ratio of the intercepted beam, thereby adjusting the intensity ratio of the dual-wavelength laser in the output beam.

[0057] Optionally, in the above optical path, the reflecting surface of the beam reflector is 45° to the incident light, so as to deflect the incident laser by 90°.

[0058] The beam reflector is also used to adjust the optical paths of the two beams.

[0059] Optionally, the beam reflector is one of a triangular prism, a plane reflector, a dielectric film reflector, a super reflector, a laser line reflector, and an elliptical reflector.

[0060] To facilitate movement, a triangular prism is selected as the beam reflector. The collimated light beam is divided into three parts along the slow axis by two triangular prisms, wherein the first triangular prism 4 is placed on the left side of the third light beam, and the second triangular prism 10 is placed on the right side of the third light beam, both of which use edge beams; the hypotenuse of the triangular prism reflects the light beam, and itself can move left and right along the direction perpendicular to the slow axis light beam to change the splitting ratio. In this example, in order to achieve higher output and better line width compression, the light beam power intercepted by a single triangular prism should be between 10% and 20% of the total power, that is, the light power entering the two wavelength selection light paths is changed.

[0061] Optionally, the light beam fast and slow axis collimation system includes an aspherical cylindrical lens 2 and a plano-convex cylindrical lens 3;

[0062] The aspherical cylindrical lens 2 is a fast axis collimator, which is used to collimate the fast axis of the blue laser single tube 1;

[0063] The plano-convex cylindrical lens 3 is a slow-axis collimator, and the curved surface direction of the plano-convex cylindrical lens is perpendicular to the aspherical cylindrical lens, and is used to collimate the slow axis of the blue laser single tube 1 .

[0064] The aspheric cylindrical lens 2 collimates the fast axis of the blue light single tube with a larger divergence angle. The size of the light spot after collimation is determined by the focal length of the fast axis collimator. The larger the focal length, the larger the collimated light and the smaller the divergence angle after collimation. The luminous characteristics of a semiconductor laser single tube have a large fast axis divergence angle and are more sensitive to the spherical aberration of the lens. Therefore, an aspheric cylindrical lens with a larger numerical aperture is selected to minimize the spherical aberration and fully collimate the fast axis laser.

[0065] Reference Figure 1 , Figure 2 , Figure 3 In this embodiment, the aspheric cylindrical lens 2 is a large-aperture aspheric cylindrical lens with a focal length of 4.5 mm and a numerical aperture of 0.64, which collimates the fast-axis beam. The plano-convex cylindrical lens 3 is an ordinary cylindrical lens with a focal length of 40 mm and a size of 20 mm×20 mm. Its front focal plane is at the light-emitting point of the laser diode, which converts the slow-axis beam from divergent light to collimated light with a low divergence angle. Since the fast and slow axes are collimated separately, the focal lengths of the collimating lenses are different, so the length of the light spot in the slow axis direction after collimation is actually longer than the length of the fast-axis beam.

[0066] The curved surface direction of the plano-convex cylindrical lens 3 is perpendicular to the aspherical cylindrical lens 2. Since the slow-axis divergence angle of the light beam is small, an ordinary plano-convex spherical lens is selected as the collimator for cost considerations. In order to achieve a better collimation effect, the focal length of the slow-axis collimator should theoretically be as large as possible. However, considering the size of the lens and the volume of the overall device, the focal length should be less than 100 mm.

[0067] Optionally, the beam expansion subsystem includes a lens pair consisting of a plano-concave spherical lens and a plano-convex spherical lens;

[0068] The focal points of the plano-concave spherical lens and the plano-convex spherical lens overlap, and the focal length of the plano-convex spherical lens is greater than the absolute value of the focal length of the plano-concave spherical lens.

[0069] The lens pair is in a geometric position with overlapping focal points, and the focal length relationship is that the focal length of the convex lens is greater than the absolute value of the focal length of the concave lens. Its function is to amplify the output light beam, reduce its divergence angle by a corresponding multiple to increase its collimation, and reduce the diffraction angle deviation caused by its own divergence angle when it is incident on the grating.

[0070] Optionally, the tunable dual-wavelength laser output device further includes an optical path deflection reflector for converging two paths of laser light onto the same transmission grating.

[0071] In this embodiment, the optical path deflecting mirror is a third plane mirror 5. In order to reduce the size of the device and reduce the cost of the device, the third plane mirror 5 is used to deflect one of the optical paths by 90°, so that the two lasers are converged on the same grating. However, it should be noted that the two light spots do not overlap.

[0072] Optionally, the laser output characteristic measurement system includes a plane spectroscope, a spectrometer and a power meter;

[0073] The plane beam splitter is 45° to the incident light;

[0074] The spectrometer is placed at the right end of the plane beam splitter to receive reflected light and detect the wavelength and line width of the output light beam;

[0075] The power meter is placed at the lower end of the plane beam splitter and is perpendicular to the transmitted light, and is used to detect the power of the received light beam.

[0076] Furthermore, the splitting ratio of the plane beam splitter is 99:1, and the power meter obtains most of the laser energy.

[0077] Reference Figure 1 , Figure 5, the first wavelength selection optical path is composed of the first triangular prism 4, the third plane reflector 5, the first plano-concave spherical lens 6, the first plano-convex spherical lens 7, the transmission grating 8, and the first plane reflector 9. After being reflected by the first triangular prism 4, the light beam is reflected again by a third plane reflector 5 whose position is fixed and whose reflection surface is perpendicular to the inclined surface of the triangular prism. Except for the change in the propagation direction, the other characteristics have not changed. Afterwards, the light beam is amplified twice by the inverted Galilean telescope system composed of the first plano-concave spherical lens 6 and the first plano-convex spherical lens 7. Compared with the Kepler telescope system composed of two convex lenses, the optical path of the concave-convex lens combination is smaller and more space-saving. Considering that the light has to enter the grating, the magnification is also limited. The focal length of the lens group selected in this embodiment is -20mm and 100mm, which magnifies the light beam by 5 times, and the divergence angle of the light beam is also reduced by 5 times accordingly, and the slow axis direction can reach 10 -5 rad level. After amplification, the light beam reaches the diffraction grating 8 at a fixed angle α. According to the diffraction formula,

[0078] d(sinθ+sinα)=mλ (1)

[0079] The number of selected grating lines is fixed. The higher the number of transmission grating lines, the stronger its spectral resolution ability and the better its line width compression effect. Therefore, the wavelength corresponds to the diffraction angle θ after passing through the grating. By adjusting the first plane reflector 9 placed behind the grating to make it perpendicular to the diffraction angle of the corresponding wavelength light to be obtained, this part of the light can return to the grating along the original path and then return directly to the blue laser single tube 1 after diffraction once according to the principle of reversibility of the optical path, completing the wavelength selection step. The remaining wavelength light beams become stray light when the transmission grating 8 is diffracted. Since the returned wavelength light beam gains an advantage in competing with the light beam under the influence of the external cavity, the diode output laser will be converted to contain only this wavelength, with a line width of less than 0.1nm, and its output power depends on the gain at this wavelength. The above is the realization principle of narrow line width laser.

[0080] Reference Figure 1 , Figure 6 The second wavelength selection optical path is composed of a second triangular prism 10, a second plano-concave spherical lens 11, a second plano-convex spherical lens 12, a transmission grating 8, and a second plane reflector 13. This optical path is independent of the first wavelength selection optical path, and the light beam is intercepted by a triangular prism. Unlike the first optical path, since the same transmission grating is used, there is no need to turn the laser transmission direction through a plane reflector in the optical path. After beam expansion by the lens pair, the second light beam is incident on different areas of the transmission grating 8 at a fixed incident angle. The angle of the second plane reflector 13 at the end of the optical path is perpendicular to the desired wavelength diffraction angle, completing the dual-wavelength single grating narrow line width output. Starting from the central wavelength of 445nm, the angle of the plane reflector behind the grating is deflected by a very small angle, and the output light wavelength also changes accordingly, thereby realizing the wavelength tuning function.

[0081] Reference Figure 1 , Figure 7 The laser output characteristic measurement system includes a plane beam splitter 14, a spectrometer 15, and a power meter 16. The collimated laser that is not split by the two triangular prisms is split into two beams by the plane beam splitter 14. The beam splitter reflects 0.1% of the blue light band laser. The reflected light is vertically incident into the spectrometer 15 on the right side of the plane beam splitter, and the transmitted light is vertically incident into the power meter 16 below. The spectrum and power characteristics of the output laser can be observed and measured at the same time. While the wavelength is tuned, the laser gain spectrum of 4nm near the central wavelength can be accurately measured according to the feedback data of the power meter and the spectrometer.

[0082] The embodiment of the present invention combines an optical lens with a diffraction grating, takes wavelength feedback as the basic principle, constructs two optical paths, selects a specific wavelength laser through a transmission grating, and outputs a high-coherence dual-wavelength laser, thereby realizing the combination of wavelength tunability, dual-wavelength output capability, and gain spectrum measurement function. It solves the problem that when a dual-wavelength laser outputs dual lasers with similar wavelengths, the regulation is relatively complex, the pump light requirements are high, and the laser line width is wide, and the problem of difficulty in obtaining a complete gain spectrum of the laser light source is caused. It not only provides flexibility and versatility, but also can perform well in various high-precision optical applications. The laser output device can flexibly adapt to different application requirements, whether in precision spectral analysis, optical communication, or in nonlinear optical processes, it can select the optimal wavelength for operation. Through wavelength tuning, the coherence of the dual-wavelength laser can be accurately controlled, which is very beneficial for applications that require precise phase control (such as interferometry and quantum optics). For example, in interferometry and nonlinear optical experiments, this laser design can significantly improve the system performance and the reliability of experimental results. When generating coherent radiation in different frequency bands of the mid-infrared or terahertz bands, the laser is able to adjust the output wavelength to optimize the frequency conversion efficiency.

[0083] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tunable dual-wavelength laser output device, characterized in that: include: Blue laser single tube, beam fast and slow axis collimation system, dual wavelength splitting line width compression system, laser output characteristic measurement system and controller; The light beam fast and slow axis collimation system is used to convert the light beam emitted by the blue laser single tube into collimated light; The dual-wavelength spectroscopic line width compression system comprises two beam reflectors, two beam expansion subsystems, a transmission grating and two plane reflectors; each of the beam reflectors is used to intercept a portion of the collimated light and enter the corresponding beam expansion subsystem for beam expansion, and the remaining collimated light enters the laser output characteristic measurement system; the transmission grating is used to diffract the beam after beam expansion and then output it to the plane reflector, and the two plane reflectors are used to reflect the vertically incident laser and return it to the blue laser single tube along the original optical path, so that the blue laser single tube outputs two specific wavelength lasers; The controller is connected to the plane reflector and is used to adjust the angle of the plane reflector so as to make it reflect laser beams of different wavelengths output by the transmission grating; The laser output characteristic measurement system is used to measure the output power and spectral characteristics of two lasers with different wavelengths; The controller is also connected to the laser output characteristic measurement system and is used to draw the gain spectrum of the blue laser single tube in the working band according to the output power and spectral characteristics of different wavelengths obtained by the laser output characteristic measurement system.

2. The tunable dual-wavelength laser output device according to claim 1, characterized in that: The two beam reflectors are arranged on both sides of the collimated light entering the laser output characteristic measurement system, and are used to intercept the edge beams of the collimated light output by the beam fast and slow axis collimation system for wavelength locking and line width compression.

3. The tunable dual-wavelength laser output device according to claim 2, characterized in that: The reflecting surface of the beam reflector is at 45° to the incident light and is used to deflect the incident laser by 90°.

4. The tunable dual-wavelength laser output device according to claim 3, characterized in that: The controller is also connected to the beam reflector and is used to control the movement of the beam reflector to change the proportion of intercepting the laser beam.

5. The tunable dual-wavelength laser output device according to claim 1, characterized in that: The beam reflector is one of a triangular prism, a plane reflector, a dielectric film reflector, a super reflector, a laser line reflector, and an elliptical reflector.

6. The tunable dual-wavelength laser output device according to claim 1, characterized in that: The light beam fast and slow axis collimation system comprises an aspherical cylindrical lens and a plano-convex cylindrical lens; The aspherical cylindrical lens is a fast axis collimator, which is used to collimate the fast axis of the blue laser single tube; The plano-convex cylindrical lens is a slow-axis collimator, the curved surface direction of which is perpendicular to the aspherical cylindrical lens, and is used to collimate the slow axis of the blue laser single tube.

7. The tunable dual-wavelength laser output device according to claim 1, characterized in that: The beam expansion subsystem includes a lens pair consisting of a plano-concave spherical lens and a plano-convex spherical lens; The focal points of the plano-concave spherical lens and the plano-convex spherical lens overlap, and the focal length of the plano-convex spherical lens is greater than the absolute value of the focal length of the plano-concave spherical lens.

8. The tunable dual-wavelength laser output device according to claim 1, characterized in that: The tunable dual-wavelength laser output device also includes an optical path deflection reflector for converging two paths of laser light onto the same transmission grating.

9. The tunable dual-wavelength laser output device according to claim 1, characterized in that: The laser output characteristic measurement system includes a plane spectroscope, a spectrometer and a power meter; The plane beam splitter is 45° to the incident light; The spectrometer is placed at the right end of the plane beam splitter to receive reflected light and detect the wavelength and line width of the output light beam; The power meter is placed at the lower end of the plane beam splitter and is perpendicular to the transmitted light, and is used to detect the power of the received light beam.

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