Laser light source and method for forming target laser

Abstract

The invention provides a laser light source and a target laser forming method, and the laser light source comprises a first laser which is used for generating first laser, the first laser comprises first single-frequency pulse laser and stray light, and the first single-frequency pulse laser has a first wavelength; the second laser is used for generating second laser, the second laser comprises single-frequency laser with a second wavelength, and the second wavelength is larger than the first wavelength; and the optical waveguide is used for inputting the first laser and the second laser, the first laser and the second laser generate stimulated Brillouin scattering in the optical waveguide to generate second single-frequency pulse laser, and the propagation direction of the second single-frequency pulse laser is opposite to that of the first single-frequency pulse laser. According to the laser, stray light in the generated second single-frequency pulse can be reduced, and the signal-to-noise ratio is improved.

Description

Technical Field

[0001] The present invention relates to a laser light source and a method for forming a target laser, and particularly to a method for converting into a single-frequency pulse without stray light by stimulated Brillouin scattering and a laser light source. Background Art

[0002] Single-frequency pulsed lasers have important applications in application fields such as long-range coherent detection, new wind energy development, and civil aviation safety meteorological assurance. To obtain a high-energy pulse output, technically, it is necessary to amplify the pulsed laser signal in multiple stages. Different from continuous-wave amplification, pulsed laser amplification has much stronger amplified spontaneous emission (ASE) stray light generated by inverted particles due to the discontinuity in the time domain, and it is rapidly amplified in each amplification stage. For example, in the 1550 nm single-frequency pulsed fiber laser reported by L. Kotov et al. (J Lightwave Technol. 41, 1526 - 1532 (2023)), the energy proportion of the ASE stray light is as high as more than 40%. In a laser, the pulsed laser signal and the ASE stray light are in a competitive relationship. Therefore, the energy proportion of the ASE stray light will affect the final output energy of the pulsed laser, causing problems such as pulsed energy saturation or self-excited oscillation resulting in amplifier failure. Spectrally, the ASE stray light appears as the spectral pedestal of the laser peak, and the ASE stray light spectrum is very wide, generally more than 30 nm.

[0003] To solve the problem of ASE stray light in lasers, the prior art uses a narrowband filter for filtering in the amplifier. A narrowband filter is a coated lens that uses the principle of light interference for optical filtering. This component needs to be customized according to the actual laser wavelength during use, so its compatibility is relatively poor. For example, for a narrowband filter with a central wavelength of 1550 nm, if the working bandwidth is 4 nm (i.e., ±2 nm), then this narrowband filter cannot be used for a 1555 nm laser. If a 1550 nm band-pass filter with a working bandwidth of 10 nm is used, although it can meet the applicable requirements of a 1555 nm laser, after the working bandwidth increases, the passed ASE wavelength range also increases, and at this time, the effect of filtering the ASE stray light becomes worse. In addition, fiber Bragg gratings can also be used for narrowband filtering. However, whether it is a narrowband filter or a fiber Bragg grating, their working principles utilize light interference. This method cannot distinguish the laser signal and the ASE stray light of the same wavelength in principle, that is, narrowband filters and fiber Bragg gratings cannot be used to improve the signal-to-noise ratio of the output laser spectrum. The improvement of the spectral signal-to-noise ratio is not only a huge improvement in the laser parameter indicators but also a foundation for obtaining higher pulsed energy.

[0004] To solve the above problems, the present application proposes a laser light source that can eliminate stray light through stimulated Brillouin scattering and improve the signal-to-noise ratio. Summary of the Invention

[0005] An object of the present application is to provide a laser light source for solving the problems in the prior art, which can eliminate the stray light in the single-frequency pulsed laser and improve the signal-to-noise ratio.

[0006] To solve the above problems, the technical solution of the present application provides a laser light source, including: a first laser for generating a first laser, the first laser including: a first single-frequency pulsed laser and stray light, the first single-frequency pulsed laser having a first wavelength; a second laser for generating a second laser, the second laser including a single-frequency laser having a second wavelength, the second wavelength being greater than the first wavelength; an optical waveguide for inputting the first laser and the second laser, the first laser and the second laser undergoing stimulated Brillouin scattering in the optical waveguide to generate a second single-frequency pulsed laser, the propagation direction of the second single-frequency pulsed laser being opposite to the propagation direction of the first single-frequency pulsed laser; a beam splitter for separating the second single-frequency pulsed laser from the first laser according to the propagation direction of the second single-frequency pulsed laser and outputting the second single-frequency pulsed laser to obtain a target laser.

[0007] Optionally, the beam splitter is located between the first laser and the optical waveguide, and the beam splitter is configured to output the light propagating along the first laser propagation direction and the light propagating in the opposite direction of the first laser propagation direction from different ports; the beam splitter is a circulator or a semi-transmissive semi-reflective mirror.

[0008] Optionally, the beam splitter includes: a first end, a second end, and an output end, one end of the optical waveguide is connected to the first laser through the circulator, the first laser inputs the first laser into the circulator through the first end, the other end of the optical waveguide is connected to the second laser, and the output end is configured to output the second single-frequency pulsed laser to obtain a target laser.

[0009] Optionally, the second laser is a fiber laser; the second laser is a fiber laser or a semiconductor laser; the beam splitter is a fiber circulator.

[0010] Optionally, it further includes: an isolator connecting the second laser and the optical waveguide, the isolator being configured to prevent the first laser from reaching the second laser.

[0011] Optionally, the first wavelength and the second wavelength satisfy:

[0012]

[0013] where λ1 is the first wavelength, λ2 is the second wavelength, va is the speed of sound, and n is the refractive index of the optical waveguide.

[0014] Optionally, the wavelength of the second laser is 900 nm to 10300 nm; the wavelength of the first single-frequency pulsed laser is 1300 nm to 1700 nm; the second laser is a pulsed laser, and the pulse repetition frequency is greater than or equal to 10 MHz; the power of the second laser is less than or equal to 1 mW.

[0015] Optionally, the optical waveguide includes an optical fiber, and the optical fiber is a polarization-maintaining optical fiber; or, the optical waveguide is a crystal with a pigtail output, and the crystal includes one or more combinations of LiNO3 or diamond.

[0016] Optionally, the first laser includes an amplifier and a pump laser, the amplifier is a rare-earth metal-doped optical fiber; the pump laser is a semiconductor laser, a solid-state laser or an optical fiber laser.

[0017] Optionally, the second laser includes one or more single-frequency pulsed lasers or the second laser is a continuous wave.

[0018] Optionally, the second laser is a mode-locked laser, a semiconductor laser or a solid-state laser, and the mode-locked laser includes: a mode-locked optical fiber laser or a mode-locked on-chip laser.

[0019] Optionally, the second laser includes one or more wavelengths.

[0020] The technical solution of the present application also provides a method for forming a target laser based on the above laser source, including: respectively inputting the first laser and the second laser into the optical waveguide through the first laser and the second laser, and the first laser and the second laser undergo stimulated Brillouin scattering in the optical waveguide to generate a second single-frequency pulsed laser, and the propagation direction of the second single-frequency pulsed laser is opposite to the propagation direction of the second single-frequency pulsed laser; outputting the second single-frequency pulsed laser to obtain the target laser.

[0021] Optionally, the laser source further includes: a beam splitter for separating the second single-frequency pulsed laser from the first laser and outputting the second single-frequency pulsed laser to obtain the target laser; the beam splitter is a circulator, and the circulator includes: a first end, a second end and an output end. One end of the optical waveguide is connected to the first laser through the circulator, the first laser inputs the first laser into the circulator through the first end, the other end of the optical waveguide is connected to the second laser, and the output end is used for outputting the second single-frequency pulsed laser to obtain the target laser;

[0022] Inputting the first laser and the second laser into the optical waveguide through a first laser and a second laser respectively includes: inputting the first laser into the first end through the first laser, and inputting the second laser into the second end through the second laser. The first laser reaches the optical waveguide through the circulator, and the first single-frequency pulsed laser and the second laser generate a second single-frequency pulsed laser in the optical waveguide;

[0023] The second single-frequency pulsed laser returns to the circulator and is output through the output end to obtain the target laser.

[0024] Optionally, the first wavelength and the second wavelength satisfy:

[0025]

[0026] where λ1 is the first wavelength, λ2 is the second wavelength, va is the speed of sound, and n is the refractive index of the optical waveguide.

[0027] The technical solution of the present invention has the following technical effects compared with the prior art:

[0028] The present invention provides a laser light source. By inputting the first laser and the second laser into the optical waveguide, the first laser and the second laser satisfy the stimulated Brillouin scattering relationship. Under the interaction of counter-propagation, the first single-frequency pulsed laser in the first laser is converted into a second single-frequency pulsed laser propagating in the reverse direction, separating it from the stray light in the first single-frequency laser, achieving the technical effect of reducing stray light.

[0029] Furthermore, by setting a separator in the laser light source and utilizing stimulated Brillouin scattering, the second single-frequency pulsed laser is made to propagate in the opposite direction to the first laser, thereby realizing the separation of the second single-frequency pulsed laser and the stray light, improving the signal-to-noise ratio, and being able to separate lasers with the same wavelength without being restricted by the laser wavelength, improving wavelength compatibility.

[0030] Furthermore, by setting the wavelength relationship between the first single-frequency pulsed laser and the second laser, the stimulated Brillouin scattering between the first single-frequency pulsed laser and the second laser can be enhanced, thereby increasing the efficiency of generating the second single-frequency pulsed laser.

[0031] Furthermore, the second laser is a mode-locked laser. Mode-locked laser usually has a spectral width of dozens of nanometers. The second laser generated by the mode-locked laser is composed of thousands of equally spaced single spectral lines. Each single spectral line is equivalent to a single-frequency pulsed laser in terms of spectrum and time domain. The second laser generated by the mode-locked laser includes multiple single-frequency lasers, enabling multiple single-frequency lasers to combine with the first single-frequency pulsed laser through stimulated Brillouin scattering to generate multiple second single-frequency pulsed lasers, thereby being able to separate the stray light from the second single-frequency laser pulses with different wavelengths. Description of the Drawings

[0032] Figures 1 to 4 It is a schematic structural diagram of the first embodiment of the laser light source of the present invention;

[0033] Figure 5 It is a flowchart of the first embodiment of the method for forming the target laser of the present invention. Detailed implementation manners

[0034] As described in the background art, in the prior art, stray light in the laser can be filtered out by a narrow-band filter or a fiber grating. However, neither the narrow-band filter nor the fiber grating can distinguish between laser signals and stray light (such as ASE stray light) of the same wavelength, and they need to be customized according to the wavelength.

[0035] To solve the problems of the prior art, the inventors of the present application found that stimulated Brillouin scattering (SBS) is a non-linear effect in the laser field and is generated when the pump laser interacts with the acoustic phonons of the medium. Assuming that the frequency of the pump laser is ω0 and the frequency of the phonon is ω1, their interaction will generate SBS laser with a frequency of ω2, and the frequency satisfies ω2 = ω0 - ω1, and the generated SBS laser is in the opposite direction to the pump laser. Therefore, SBS can be used to distinguish between laser signals and ASE stray light of the same wavelength, completely eliminate ASE stray light, and thus improve the signal-to-noise ratio of the laser spectrum.

[0036] Based on the above analysis, the present invention provides a laser light source, including a first laser for generating a first laser, the first laser including: a first single-frequency pulsed laser and stray light, the first single-frequency pulsed laser having a first wavelength; a second laser for generating a second laser, the second laser including a single-frequency laser having a second wavelength, the second wavelength being greater than the first wavelength; an optical waveguide for inputting the first laser and the second laser, and the first laser and the second laser undergo stimulated Brillouin scattering in the optical waveguide to generate a second single-frequency pulsed laser, and the propagation direction of the second single-frequency pulsed laser is opposite to the propagation direction of the first single-frequency pulsed laser. The laser of the present application can reduce the stray light in the generated second single-frequency pulse and improve the signal-to-noise ratio.

[0037] Figures 1 to 4 It is a schematic structural diagram of the first embodiment of the laser light source provided by the present invention.

[0038] The first embodiment of the laser light source of the present invention will be further described in detail with reference to the accompanying drawings.

[0039] Please refer to Figure 1, the laser light source includes: a first laser 10 for generating a first laser, the first laser including: a first single-frequency pulsed laser and stray light, the first single-frequency pulsed laser having a first wavelength; a second laser 40 for generating a second laser, the second laser including a single-frequency laser having a second wavelength greater than the first wavelength; an optical waveguide 30 for inputting the first laser and the second laser, the first laser and the second laser undergoing stimulated Brillouin scattering in the optical waveguide 30 to generate a second single-frequency pulsed laser, the propagation direction of the second single-frequency pulsed laser being opposite to the propagation direction of the first single-frequency pulsed laser; and a beam splitter for separating the second single-frequency pulsed laser from the first laser according to the propagation direction of the second single-frequency pulsed laser and outputting the second single-frequency pulsed laser to obtain a target laser.

[0040] In the technical solution of the present application, by inputting the first laser and the second laser into the optical waveguide 30, the first laser and the second laser are made to satisfy the stimulated Brillouin scattering relationship. Under the interaction of counter-propagation, the first single-frequency pulsed laser in the first laser is converted into a second single-frequency pulsed signal laser propagating in the opposite direction, which is separated from the first laser, achieving the technical effect of reducing stray light.

[0041] In this embodiment, the laser light source further includes: a beam splitter 20 for separating the second single-frequency pulsed laser from the first laser and outputting the second single-frequency pulsed laser to obtain a target laser.

[0042] Specifically, as Figure 3 shown, in this embodiment, the beam splitter 20 includes: a first end 1, a second end 2, and an output end 3. One end of the optical waveguide 30 is connected to the first laser 10 through the circulator. The first laser 10 inputs the first laser into the circulator through the first end 1. The other end of the optical waveguide 30 is connected to the second laser 40. The output end 3 is used to output the second single-frequency pulsed laser to obtain a target laser.

[0043] The beam splitter is located between the first laser and the optical waveguide, and the beam splitter is used to output light propagating along the propagation direction of the first laser and in the opposite direction to the propagation direction of the first laser from different ports; the beam splitter is a circulator or a semi-transparent semi-reflective mirror. Specifically, in this embodiment, the beam splitter 20 includes: a circulator.

[0044] In other embodiments of the present application, the beam splitter 20 may also be a semi-transparent semi-reflective mirror. The first laser 10 and the second laser 40 may also be semiconductor lasers or solid-state lasers. The first laser 10, the second laser 40, the beam splitter 20, and the optical waveguide 30 may be transmitted through spatial light.

[0045] In this embodiment, the first laser 10 includes an amplifier and a pump laser 11. During the process of laser amplification in the amplifier 12, stray light, including ASE stray light, is inevitably generated.

[0046] Specifically, the amplifier 12 is an optical fiber amplifier, and the amplifier 12 is an optical fiber doped with rare earth metals; the rare earth metal doped in the amplifier 12 is ytterbium, and the optical fiber amplifier is a ytterbium-doped optical fiber amplifier.

[0047] The pump laser 11 is a semiconductor laser, a solid-state laser or an optical fiber laser. In this embodiment, the pump laser 11 is an optical fiber laser. In other embodiments, the pump laser may be a semiconductor laser or a solid-state laser.

[0048] Specifically, the pump laser 11 includes: a continuous light source and a modulator. The continuous light source is used to generate continuous laser, and the modulator is used to convert the continuous laser into pulsed laser. Specifically, the continuous light source is a single-frequency ytterbium-doped optical fiber laser, and the modulator is an acousto-optic modulator. The amplifier is an optical fiber amplifier, and the optical fiber amplifier is a ytterbium-doped optical fiber amplifier. The initial laser output by the continuous light source is continuous-wave single-frequency laser. The initial laser generates single-frequency pulsed laser after passing through the acousto-optic modulator. The single-frequency pulsed laser is input into the amplifier 30 and undergoes multi-stage amplification to form the first laser. The first laser includes the first single-frequency pulsed laser and the stray light. The wavelength of the first single-frequency laser is 1064 nm. The pump laser 11 is a single-frequency ytterbium-doped optical fiber laser.

[0049] In this embodiment, the optical waveguide 30 includes an optical fiber. Specifically, the optical fiber is a single-mode polarization-maintaining optical fiber. Alternatively, the optical waveguide 30 is a crystal with a pigtail output, and the crystal includes one or a combination of LiNO3 or diamond.

[0050] The second laser 40 is a mode-locked laser, a semiconductor laser or a solid-state laser. The mode-locked laser includes: a single-frequency optical fiber laser, a mode-locked optical fiber laser or a mode-locked on-chip laser.

[0051] As Figure 2 shown, in this embodiment, the laser light source further includes: an isolator 50 connecting the second laser 40 and the optical waveguide 30. The isolator 50 is used to prevent the first laser from reaching the second laser 40. The isolator 50 can block the first laser transmitted to the second laser 40, thereby ensuring the stability of the second laser 40.

[0052] Figure 3 It is a schematic structural diagram of a circulator in the first embodiment of the laser light source of the present application.

[0053] Reference Figure 3 In this embodiment, the first laser 10 generates first laser light that enters the circulator through the first end 1 and is output from the second end 2 of the circulator to the optical waveguide 30. The second laser 40 generates second laser light that enters the optical waveguide 30 after passing through the isolator 50. The second laser light meets the first laser light in the optical waveguide 30. The first single-frequency pulsed laser light in the first laser light undergoes stimulated Brillouin scattering with the second laser light to generate second single-frequency pulsed laser light. The direction of the second single-frequency pulsed laser light is opposite to that of the first single-frequency pulsed laser light. The stray light does not interact and its propagation direction remains unchanged. Therefore, the propagation direction of the second single-frequency pulsed laser light is opposite to that of the stray light. The second single-frequency pulsed laser light is transmitted from the optical waveguide 30 to the beam splitter 20 and is output from the output end 3 of the beam splitter 20 to form the target laser light.

[0054] When the first laser light and the second laser light satisfy the following conditions, the stimulated Brillouin scattering of the first laser light and the second laser light can be enhanced, thereby increasing the efficiency of generating the second single-frequency laser light.

[0055] Specifically, the first wavelength and the second wavelength satisfy:

[0056]

[0057] where λ1 is the first wavelength, λ2 is the second wavelength, v a is the speed of sound, and n is the refractive index of the optical waveguide.

[0058] In the technical solution of this application, the wavelength of the second laser light is 900 nm to 10300 nm; the wavelength of the first single-frequency pulsed laser light is 1300 nm to 1700 nm, and the first single-frequency pulsed laser light is a single-frequency laser. The second laser light can be a single-frequency laser or a multi-wavelength laser, and the second laser light is a pulsed light or a continuous light.

[0059] Combined with reference Figure 4 , Figure 4 (a) is the input spectrum at the first end 1 of the beam splitter 20, Figure 4 (b) shows the output spectrum at the output end 3 of the beam splitter 20.

[0060] Specifically, in an embodiment of the present invention, the second laser 40 is a semiconductor laser, the second wavelength is 1550.13 nm, and the first wavelength is 1550 nm. The second laser light is a continuous wave, and the power of the second laser light is less than or equal to 1 mW. Specifically, the laser power is 50 μW.

[0061] The optical waveguide 30 is a single-mode polarization-maintaining optical fiber. Reference Figure 4, the wavelength of the formed second single-frequency pulsed laser is the same as the second wavelength, and the wavelength of the second single-frequency pulsed laser is 1550.13 nm. The ASE stray light has been eliminated in the output second single-frequency pulsed laser, improving the signal-to-noise ratio.

[0062] In another embodiment of the present invention, the second laser includes one or more single-frequency pulsed lasers.

[0063] Specifically, the second laser 40 is a mode-locked laser. The mode-locked laser is a mode-locked fiber laser. In other embodiments, the mode-locked laser is a mode-locked on-chip laser. The first laser 10 is a fiber laser, the second laser 40 is a fiber laser, the optical waveguide 30 is a fiber, and the circulator is a fiber circulator. Then, the first laser 10, the second laser 40, the beam splitter 20, and the optical waveguide 30 can all couple light through the fusion of fibers, thereby reducing the loss of light energy.

[0064] The second laser 40 is a mode-locked laser. Mode-locked lasers usually have a spectral width of dozens of nanometers. The second laser generated by the mode-locked laser is composed of thousands of equally spaced single spectral lines. Each single spectral line is equivalent to a single-frequency pulsed laser in terms of spectrum and time domain. The second laser generated by the mode-locked laser includes multiple single-frequency lasers. Combining multiple single-frequency pulses with stimulated Brillouin scattering can separate the stray light from the second single-frequency laser pulse.

[0065] The second laser includes one or more wavelengths. Specifically, in this embodiment, the second laser is multi-wavelength. Specifically, the second wavelength of the second laser is 1030 nm to 1090 nm, and the pulse repetition frequency of the second laser is 10 MHz to 100 MHz. Specifically, the pulse repetition frequency of the second laser is 50 MHz.

[0066] The optical waveguide 30 is a single-mode polarization-maintaining fiber. The first single-frequency pulsed laser and the second laser meet in the optical waveguide 30. Adjust the temperature or current of the first single-frequency laser to match the comb teeth of the mode-locked laser of the second laser. The first single-frequency pulsed laser and the second laser undergo stimulated Brillouin scattering in the optical waveguide 30, generating a second single-frequency pulsed laser in the opposite direction to the transmission direction of the first single-frequency pulsed laser. The wavelength of the second single-frequency pulsed laser is 1064.06 nm.

[0067] The technical solution of the present application also provides a method for forming a target laser through a laser light source. Figure 5 It is a flowchart of the first embodiment of the method for forming a target laser through a laser light source in the present application.

[0068] Refer to Figure 5, the method for forming the target laser through a laser light source includes:

[0069] Step SP1, input the first laser and the second laser into the optical waveguide through a first laser and a second laser respectively. The first laser and the second laser undergo stimulated Brillouin scattering in the optical waveguide to generate a second single-frequency pulsed laser, and the propagation direction of the second single-frequency pulsed laser is opposite to the propagation direction of the second single-frequency pulsed laser;

[0070] Step SP2, output the second single-frequency pulsed laser to obtain the target laser.

[0071] In this embodiment, the laser light source further includes: a beam splitter 20, configured to separate the second single-frequency pulsed laser from the first laser and output the second single-frequency pulsed laser to obtain the target laser.

[0072] The beam splitter 20 includes a circulator. The circulator includes: a first end 1, a second end 2, and an output end 3. One end of the optical waveguide 30 is connected to the first laser 10 through the circulator. The first laser 10 inputs the first laser into the circulator through the first end 1. The other end of the optical waveguide 30 is connected to the second laser 40, and the output end 3 is used to output the second single-frequency pulsed laser to obtain the target laser.

[0073] Specifically, the laser light source in this embodiment can be the same as Figures 1 to 4 the laser light source provided in this application as shown. The embodiments of the laser light source of this application can all be cited herein.

[0074] Specifically, in this embodiment, inputting the first laser and the second laser into the optical waveguide 30 through the first laser 10 and the second laser 40 respectively includes: inputting the first laser into the first end 1 through the first laser 10 and inputting the second laser into the second end 2 through the second laser 40. The first laser reaches the optical waveguide 30 through the circulator, and the first single-frequency pulsed laser and the second laser generate a second single-frequency pulsed laser in the optical waveguide 30; the second single-frequency pulsed laser returns to the circulator and is output through the output end 3 to obtain the target laser.

[0075] In this embodiment, the first wavelength and the second wavelength satisfy:

[0076]

[0077] where λ1 is the first wavelength, λ2 is the second wavelength, v a is the sound speed, and n is the refractive index of the optical waveguide.

[0078] In this embodiment, the first laser 10 includes an amplifier 12 and a pump laser 11. The amplifier 12 is a rare-earth metal-doped optical fiber; the pump laser 11 is a semiconductor laser, a solid-state laser or an optical fiber laser. The laser light source further includes an isolator 50 connecting the second laser 40 and the optical waveguide 30. The isolator 50 is used to prevent the first laser from reaching the second laser 40. The isolator 50 can prevent the first laser transmitted to the second laser 40, thereby ensuring the stability of the second laser 40.

[0079] The first laser is input to the first end 1 through the first laser 10. The first laser reaches the optical waveguide 30 through the circulator, including: turning on the pump laser 11 to generate pump light. The pump light is amplified in the amplifier 12 to generate the first laser, and the first laser is input to the optical waveguide 30 through the first end 1.

[0080] In this embodiment, the second laser is input to the second end 2 through the second laser 40, including the second laser generated by the second laser 40 entering the optical waveguide 30 through the isolator 50;

[0081] The first laser and the second laser generate a second single-frequency pulsed laser in the optical waveguide 30; the single-frequency pulsed laser returns to the circulator and is output through the output end 3 to obtain the target laser, including: the second laser meets the first laser in the optical waveguide 30. The first single-frequency pulsed laser in the first laser undergoes stimulated Brillouin scattering with the second laser to generate a second single-frequency pulsed laser. The direction of the second single-frequency pulsed laser is opposite to that of the first single-frequency pulsed laser, and the stray light does not interact and its propagation direction remains unchanged; the second single-frequency pulsed laser is transmitted from the optical waveguide 30 to the beam splitter 20 and is output from the output end 3 of the beam splitter 20 to form the target laser.

[0082] The above specific embodiments are used to explain the present invention. They are only the preferred embodiments of the present invention and do not limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and scope of the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A laser light source, characterized in that: Comprising: A first laser for generating first laser light, the first laser light including: first single-frequency pulsed laser light and stray light, the first single-frequency pulsed laser light having a first wavelength; A second laser for generating second laser light, the second laser light including single-frequency laser light having a second wavelength greater than the first wavelength; An optical waveguide for inputting the first laser light and the second laser light, the first laser light and the second laser light undergoing stimulated Brillouin scattering in the optical waveguide to generate second single-frequency pulsed laser light, the propagation direction of the second single-frequency pulsed laser light being opposite to the propagation direction of the first single-frequency pulsed laser light; A beam splitter for separating the second single-frequency pulsed laser light from the first laser light according to the propagation direction of the second single-frequency pulsed laser light and outputting the second single-frequency pulsed laser light to obtain target laser light.

2. The laser light source according to claim 1, wherein: The beam splitter is located between the first laser and the optical waveguide, and the beam splitter is used to output light propagating in the direction of the first laser light and light propagating in the direction opposite to the first laser light from different ports; the beam splitter is a circulator or a semi-transparent semi-reflective mirror.

3. The laser light source according to claim 2, characterized in that: The beam splitter includes: a first end, a second end, and an output end. One end of the optical waveguide is connected to the first laser through the circulator. The first laser inputs the first laser light into the circulator through the first end. The other end of the optical waveguide is connected to the second laser, and the output end is used to output the second single-frequency pulsed laser light to obtain target laser light.

4. The laser light source according to claim 3, wherein: The second laser is a fiber laser; the second laser is a fiber laser or a semiconductor laser; the beam splitter is a fiber circulator.

5. The laser light source according to claim 1, wherein: Further comprising: An isolator connecting the second laser and the optical waveguide, the isolator being used to prevent the first laser light from reaching the second laser.

6. The laser light source according to claim 1, characterized in that: The first wavelength and the second wavelength satisfy: where λ1 is the first wavelength, λ2 is the second wavelength, v a is the speed of sound, and n is the refractive index of the optical waveguide.

7. The laser light source according to claim 6, wherein: The wavelength of the second laser light is 900 nm to 10300 nm; the wavelength of the first single-frequency pulsed laser light is 1300 nm to 1700 nm; the second laser light is pulsed laser light, and the pulse repetition frequency is greater than or equal to 10 MHz; the power of the second laser light is less than or equal to 1 mW.

8. The laser light source according to any one of claims 1, characterized in that: The optical waveguide includes an optical fiber, and the optical fiber is a polarization-maintaining optical fiber; or, The optical waveguide is a crystal with a pigtail output, and the crystal includes one or a combination of LiNO3 or diamond.

9. The laser light source according to claim 1, characterized in that: The first laser includes an amplifier and a pump laser, the amplifier being a rare-earth metal-doped optical fiber; the pump laser being a semiconductor laser, a solid-state laser, or a fiber laser.

10. The laser light source according to claim 1, wherein: The second laser light includes one or more single-frequency pulsed laser lights or the second laser light is continuous wave.

11. The laser light source according to claim 10, characterized in that: The second laser is a mode-locked laser, a semiconductor laser, or a solid-state laser, and the mode-locked laser includes: a mode-locked fiber laser or a mode-locked on-chip laser.

12. The laser light source according to claim 11, wherein: The second laser light includes one or more wavelengths.

13. A method for forming a target laser based on the laser light source according to any one of claims 1 to 12, characterized in that, Comprising: The first laser and the second laser are respectively input into the optical waveguide, and the first laser and the second laser undergo stimulated Brillouin scattering in the optical waveguide to generate a second single-frequency pulsed laser, and the propagation direction of the second single-frequency pulsed laser is opposite to the propagation direction of the second single-frequency pulsed laser; The second single-frequency pulsed laser is output to obtain a target laser.

14. The method for forming a target laser according to claim 13, wherein: The laser light source further includes: a beam splitter for separating the second single-frequency pulsed laser from the first laser and outputting the second single-frequency pulsed laser to obtain a target laser; the beam splitter is a circulator, and the circulator includes: a first end, a second end, and an output end. One end of the optical waveguide is connected to the first laser through the circulator, the first laser inputs the first laser into the circulator through the first end, the other end of the optical waveguide is connected to the second laser, and the output end is used to output the second single-frequency pulsed laser to obtain a target laser; Respectively inputting the first laser and the second laser into the optical waveguide through the first laser and the second laser includes: inputting the first laser into the first end through the first laser and inputting the second laser into the second end through the second laser, the first laser reaches the optical waveguide through the circulator, and the first single-frequency pulsed laser and the second laser generate a second single-frequency pulsed laser in the optical waveguide; The second single-frequency pulsed laser returns to the circulator and is output through the output end to obtain the target laser.

15. The method for forming a target laser according to claim 13, wherein: The first wavelength and the second wavelength satisfy: where λ1 is the first wavelength, λ2 is the second wavelength, v a is the speed of sound, and n is the refractive index of the optical waveguide.

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