High-energy optical parametric oscillator and mid-far infrared optical parametric oscillator

Abstract

The embodiment of the present application provides a kind of high-energy optical parametric oscillator, especially mid-far infrared optical parametric oscillator.The high-energy optical parametric oscillator includes: pump light emitting module, frequency conversion module, optical spectrum beam combining module and output coupling mirror arranged in sequence along the optical path;Wherein, pump light emitting module is used to emit multiple beams of pump light of preset wavelength to frequency conversion module;Frequency conversion module includes multiple optical parametric frequency conversion modules, and optical parametric frequency conversion module is used to convert received pump light into parametric light;Optical spectrum beam combining module is used to perform optical spectrum beam combining on multiple beams of parametric light generated by frequency conversion module to form combined beam light, and combined beam light is transmitted to output coupling mirror;Output coupling mirror is used to reflect part of combined beam light back to each optical parametric frequency conversion module to form feedback oscillation, and another part of combined beam light is output.The high-energy optical parametric oscillator realizes the output of high beam quality high-energy parametric light using simple optical device combination.

Description

Technical Field

[0001] This invention relates to the field of high-energy optical parametric oscillators, and more particularly to a high-energy optical parametric oscillator and a mid- to far-infrared optical parametric oscillator. Background Technology

[0002] An optical parametric oscillator (OPO) is a device that generates laser light of a specific wavelength using nonlinear optical effects. A high-energy OPO refers to a device capable of generating high-energy output (such as providing high-brightness laser light). High-energy OPOs have important applications in materials science, spectroscopy, medicine, and the military.

[0003] Existing high-energy parametric optical technologies mainly include optical parametric oscillators (OPOs) and optical parametric amplifiers (OPAs). However, the output energy of an OPO is limited by crystal gain and device damage threshold. To achieve high-energy parametric optical output, an OPA requires not only a high-energy fundamental pump light but also a high-beam-quality seed signal light, and the two beams must be matched in time and space, which increases the complexity of the entire experimental setup. Summary of the Invention

[0004] This invention provides a high-energy optical parametric oscillator, particularly a mid-to-far-infrared optical parametric oscillator, to overcome the deficiency of existing optical parametric oscillators in being unable to output high-energy parametric light, and to realize the output of high-beam-quality high-energy parametric light using a simple combination of optical devices.

[0005] In a first aspect, embodiments of the present invention provide a high-energy optical parametric oscillator, comprising: a pump light emitting module, a frequency conversion module, a spectral beam combining module, and an output coupling mirror arranged sequentially along an optical path; wherein...

[0006] The pump light emitting module is used to emit multiple beams of pump light with preset wavelengths to the frequency conversion module; wherein, the multiple beams of pump light have the same wavelength;

[0007] The frequency conversion module includes multiple optical parametric frequency conversion modules, which are used to convert the received pump light into parametric light; wherein, the multiple pump light beams emitted by the pump light emitting module are input to the multiple optical parametric frequency conversion modules one by one, and the wavelengths of the parametric light output by different optical parametric frequency conversion modules are different.

[0008] The spectral beam combining module is used to combine multiple beams of parametric light output from the frequency conversion module to form a combined beam, and then transmit the combined beam to the output coupling mirror.

[0009] The output coupling mirror is used to reflect a portion of the combined light back to each of the optical parametric frequency conversion modules to form feedback oscillation, and output the other portion of the combined light.

[0010] In one possible implementation, the optical parametric frequency conversion module includes an optical parametric high reflectivity mirror and an optical parametric frequency conversion crystal arranged sequentially along the optical path;

[0011] The frequency conversion module, the spectral beam combining module, and the output coupling mirror together constitute an optical parametric oscillation cavity.

[0012] In one possible implementation, the optical parametric high reflectivity mirror of the optical parametric oscillating cavity is coated with a first antireflection film and a high reflectivity film, wherein the first antireflection film has a transmittance of more than 95% for pump light, and the wavelength of the high reflectivity film covers the wavelength of the parametric light.

[0013] In one possible implementation, the spectral beam combining module includes an optical conversion element and a diffractive optical element arranged sequentially along the optical path, wherein the optical conversion element is used to transmit multiple beams of parametric light to the same position of the diffractive optical element; the diffractive optical element is used to perform spectral beam combining on the multiple beams of parametric light and transmit the resulting combined beam to the output coupling mirror.

[0014] In one possible implementation, the optical transformation element is a lens, the diffractive optical element is a grating, and the diffractive optical element is located at the focal plane of the optical transformation element.

[0015] In one possible implementation, the parametric light is incident on the diffractive optical element at a preset incident angle according to a preset incident angle formula, wherein the preset incident angle calculation formula is as follows:

[0016]

[0017] In the formula, λ is the wavelength of the parametric light band, d is the groove spacing of the diffractive optical element, α is the incident angle, and β is the diffraction angle.

[0018] In one possible implementation, the output coupling mirror is coated with a second antireflection film, the second antireflection film having a transmittance of more than 95% for one of the signal light and the idler light, and a transmittance of 10% to 80% for the other.

[0019] In one possible implementation, the pump light emission module includes a plurality of pump laser emitters that correspond one-to-one with the optical parametric frequency conversion module.

[0020] In one possible implementation, the multiple optical parametric oscillation cavities of the optical parametric frequency conversion module are arranged in a straight line with equal spacing.

[0021] In a second aspect, embodiments of the present invention provide a mid-to-far infrared optical parametric oscillator, including the first aspect and / or various possible implementations of the first aspect.

[0022] The high-energy optical parametric oscillator provided by this invention includes: a pump light emitting module, a frequency conversion module, a spectral beam combining module, and an output coupling mirror arranged sequentially along the optical path. The pump light emitting module emits multiple beams of pump light with preset wavelengths to the frequency conversion module. The frequency conversion module includes multiple optical parametric frequency conversion modules, which are used to convert the received pump light into parametric light. The multiple pump light beams emitted by the pump light emitting module are input to the multiple optical parametric frequency conversion modules one-to-one, and the multiple pump light beams have the same wavelength, while the output parametric light from different optical parametric oscillators has different wavelengths. The spectral beam combining module is used to spectrally combine the multiple parametric light beams generated by the frequency conversion module and transmit the resulting combined light to the output coupling mirror. The output coupling mirror is used to reflect a portion of the combined light back to each optical parametric frequency conversion module along the original path to form feedback oscillation, and output the other portion of the combined light. As can be seen, the technical solution provided by this invention outputs multiple beams of parametric light of different wavelengths through multiple optical parametric frequency conversion modules, and then combines these beams into a single beam using a spectral combining module. Therefore, the beam quality of the combined parametric light is essentially the same as that of a single beam of parametric light (i.e., the parametric light output individually by each optical parametric frequency conversion module). The combined parametric light is output through an output coupling mirror. Since the combined light contains the beam energy of multiple single parametric beams, it effectively concentrates energy for output, meaning the output combined parametric light has greater energy than a single beam of parametric light. A portion of the combined light is returned to the optical parametric frequency conversion module, enabling the module to start and oscillate continuously at a specific wavelength. Furthermore, this high-energy optical parametric oscillator employs a modular structure, which facilitates the inspection, repair, or replacement of individual modules in case of oscillator failure. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is one of the optical path schematic diagrams of the high-energy optical parametric oscillator provided by the present invention;

[0025] Figure 2 This is the second schematic diagram of the optical path of the high-energy optical parametric oscillator provided by the present invention;

[0026] Figure 3 This is the third schematic diagram of the optical path of the high-energy optical parametric oscillator provided by the present invention;

[0027] Figure 4 This is the fourth schematic diagram of the optical path of the high-energy optical parametric oscillator provided by the present invention;

[0028] Figure label:

[0029] 1: Pump light emission module; 11: Pump laser emitter; 2: Frequency conversion module; 21: Optical parametric frequency conversion module; 211: Optical parametric high reflectivity mirror; 212: Optical parametric frequency conversion crystal; 3: Spectral beam combining module; 31: Optical conversion element; 32: Diffractive optical element; 4: Output coupling mirror. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] Optical parametric oscillators (OPOs) and optical parametric amplifiers (OPAs) are both devices based on nonlinear optical effects. They utilize specific nonlinear media (such as certain types of crystals) to achieve frequency conversion of light waves. An OPO uses a nonlinear crystal as its working medium to convert laser wavelengths to other wavelengths through second-order nonlinear polarization (three-wave interaction). It offers advantages such as flexible output wavelength conversion, wide tuning range, good beam quality, and a simple and compact structure. However, the crystal is a crucial component in an OPO. Located in the light propagation path, it is the core element for realizing the optical parametric oscillation process. The crystal's gain characteristics determine the energy conversion efficiency from pump light to signal light and idler light. The crystal's gain is finite. During optical parametric oscillation, when the energy of the signal light and idler light increases to a certain level, the output energy reaches a limited state because the crystal gain can no longer support further energy conversion. Simultaneously, as the pump light energy increases, the light intensity inside the crystal also increases. When the light intensity reaches the crystal's damage threshold, the crystal will be damaged (e.g., develop cracks). Therefore, the pump light energy cannot be increased indefinitely, thus limiting the output energy of the optical parametric oscillator (OPA). The working principle of an OPA utilizes the parametric amplification process in a nonlinear medium. When a high-intensity pump light and a weaker signal light propagate in the same direction through the nonlinear medium, part of the pump light's energy is transferred to the signal light, leading to an increase in the signal light's amplitude. Simultaneously, a new light wave with a frequency equal to or less than the sum of the pump light's frequency—the idler frequency—is generated. Therefore, achieving high-energy parametric light output with an OPA requires not only a high-energy fundamental pump light but also a high-beam-quality seed signal light, and the two beams must be matched in time and space, increasing the complexity of the entire device to some extent.

[0032] Based on the above, it can be seen that in the existing technology, there is a technical problem that parametric optical oscillators with simple structures cannot output high-energy parametric light.

[0033] The high-energy optical parametric oscillator provided by this invention solves the technical problem that simple parametric oscillators cannot output high-energy parametric light by combining multiple beams of parametric light into a single beam for output.

[0034] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0035] Figure 1 This is one of the optical path schematic diagrams of the high-energy optical parametric oscillator provided by the present invention, such as...Figure 1 As shown, the high-energy optical parametric oscillator includes: a pump light emitting module 1, a frequency conversion module 2, a spectral beam combining module 3, and an output coupling mirror 4 arranged sequentially along the optical path.

[0036] Pump light emitting module 1 is used to emit multiple beams of pump light with preset wavelengths to frequency conversion module 2. The multiple beams of pump light have the same wavelength.

[0037] The pump light can be a fundamental frequency pump light of a preset wavelength required to generate optical parametric frequency conversion.

[0038] For example, the fundamental frequency pump light can be continuous light, quasi-continuous light, or pulsed light, etc., wherein the pulse width of the pulsed light can be at the millisecond, microsecond, nanosecond, picosecond, or femtosecond level. The preset wavelength of the fundamental frequency pump light can be 532nm, 1064nm, or 2100nm, etc.

[0039] For example, the preset wavelength of the fundamental frequency pump light can be 532nm, 1064nm, or 2100nm, etc.

[0040] The frequency conversion module 2 includes multiple optical parametric frequency conversion modules 21, which are used to convert the received pump light into parametric light. The multiple pump beams emitted by the pump light emitting module 1 are input to the multiple optical parametric frequency conversion modules 21 one-to-one, and the wavelengths of the parametric light output by different optical parametric frequency conversion modules 21 are different.

[0041] In this system, the number of fundamental frequency pump light beams emitted by pump light emitting module 1 is comparable to the number of frequency conversion modules 2. One fundamental frequency pump light beam corresponds to one input optical parametric frequency conversion module 21, and outputs one parametric light beam. The optical parametric frequency conversion module 21 can convert a fundamental frequency pump light of one frequency into a coherent output of signal light and idler light, the sum of which equals the frequency of the pump light. The wavelengths λs and λi of the signal light and idler light output by an optical parametric frequency conversion module 21 satisfy 1 / λp = 1 / λs + 1 / λi, where λp is the pump light wavelength. Different optical parametric frequency conversion modules 21 output different wavelengths of signal light and idler light. However, the wavelengths of the parametric light (signal light and idler light) output by different optical parametric frequency conversion modules 21 belong to the same wavelength range.

[0042] The spectral beam combining module 3 is used to combine the multiple parametric beams generated by the frequency conversion module 2 into a combined beam, and then transmit the combined beam to the output coupling mirror 4.

[0043] Understandably, spectral beam combining is a beam combining technique that combines multiple laser beams with a certain spectral spacing into a single beam to increase output power (energy) while maintaining beam quality as much as possible. Spectral beam combining module 3 can achieve spectral beam combining by utilizing the different wavelengths of the components in multiple parametric beams that have different offsets, ultimately causing these components to propagate in the same direction.

[0044] The spectral beam combining module 3 combines the parametric light of different wavelengths generated by the different optical parametric frequency conversion modules 21 of the frequency conversion module 2 into a single beam (parametric light). The beam quality of this combined beam is basically consistent with the beam quality of the single parametric light output by each optical parametric frequency conversion module 21. However, the energy of this combined beam is the sum of the energy of multiple single parametric light beams, thus achieving the output of high-energy parametric light while maintaining the beam quality of the final output parametric light. Furthermore, spectral beam combining does not require the synthesized beam to have temporal coherence, which helps to achieve stable operation at high power levels.

[0045] Output coupling mirror 4 is used to reflect a portion of the combined beam back to each optical parameter frequency conversion module 21 along the original path, and output the other portion of the combined beam.

[0046] Understandably, returning a portion of the parametric light to the optical parametric conversion module 21 is to establish and maintain feedback for the oscillation process, which is crucial for the startup and stable operation of the oscillation cavity. The optical parametric conversion module 21 relies on parametric processes in a nonlinear crystal to convert the pump light into signal and idler light. In this process, the energy of the pump light is split into two parts, forming signal and idler light, which are typically interdependent and require the conditions of energy and momentum conservation to be met. Returning a portion of the parametric light to the nonlinear crystal ensures that a stable three-wave mixing state can be maintained between the pump, signal, and idler light. This maximizes the efficiency of the parametric conversion, enabling the optical parametric conversion module to start and oscillate continuously at a specific wavelength. Without proper feedback, even if the nonlinear crystal and pump light conditions meet the requirements, oscillation is difficult to establish because the initial intensity of the signal and idler light is insufficient for self-reinforcement through the nonlinear process. The returned parametric light also helps stabilize the oscillation process and reduces frequency drift caused by fluctuations in pump light intensity or temperature changes.

[0047] The high-energy optical parametric oscillator provided in this embodiment can flexibly change the wavelength of the output parametric light by adjusting the relevant parameters of the optical parametric frequency conversion module 21. Multiple optical parametric frequency conversion modules 21 can generate parametric light of different wavelengths, which are then combined by the spectral beam combining module 3, thus effectively focusing and outputting energy. In some applications requiring high-energy lasers, such as laser cutting of thick metal materials, high-energy output can improve cutting speed and quality. Finally, the output coupling mirror 4 reflects a portion of the combined light back to each optical parametric frequency conversion module 21 along the original path. This energy feedback mechanism helps to increase the optical energy density within the cavity. During optical parametric oscillation, higher energy density can improve conversion efficiency, allowing more pump light energy to be converted into parametric light energy, thereby further improving the overall energy output. Simultaneously, this high-energy optical parametric oscillator adopts a modular structure, which facilitates the inspection, repair, or replacement of individual modules when the oscillator device malfunctions. At the same time, if it is necessary to upgrade the equipment, such as increasing the power of the pump light emitting module 1 or improving the performance of the frequency conversion module 2, the corresponding modules can be replaced or improved relatively easily.

[0048] Figure 2 This is the second schematic diagram of the optical path of the high-energy optical parametric oscillator provided by the present invention, as shown below. Figure 2 As shown, this high-energy optical parametric oscillator includes: a pump light emitting module 1, a frequency conversion module 2, a spectral beam combining module 3, and an output coupling mirror 4, arranged sequentially along the optical path. The functions of these optical components are the same as described above. Figure 1 The functions of optical components are the same, so they will not be elaborated here.

[0049] In this embodiment, the optical parametric frequency conversion module 21 includes an optical parametric high reflectivity mirror 211 and an optical parametric frequency conversion crystal 212 arranged sequentially along the optical path. It should be noted that the frequency conversion module 2 (including multiple optical parametric frequency conversion modules 21), the spectral beam combining module 3, and the output coupling mirror 4 together constitute an optical parametric oscillation cavity.

[0050] The optical parametric high reflectivity mirror 211 is a mirror with very high optical reflectivity, such as a plane mirror, within a specific wavelength or wavelength range. The optical parametric frequency conversion crystal 212 is where the pump light is converted into signal and idler frequencies. By adjusting the crystal's angle or using different types of crystals, the signal and idler frequencies can be controlled within a specific wavelength range. Here, the optical parametric high reflectivity mirror 211 has extremely high reflectivity for the specific wavelengths of the signal and idler frequencies generated by the optical parametric frequency conversion module 21, while allowing the pump light wavelength to pass through. This ensures that the signal and idler frequencies propagate back and forth within the optical parametric frequency conversion crystal 212, accumulating energy through the parametric amplification process until a sufficient threshold is reached to achieve self-excited oscillation.

[0051] In one possible implementation, the optical parametric high reflectance mirror 211 of the optical parametric frequency conversion module 21 is coated with a first antireflection film and a high reflectance film, wherein the first antireflection film has a transmittance of more than 95% for pump light (fundamental frequency pump light), and the wavelength of the high reflectance film covers the wavelength of the parametric light.

[0052] Understandably, the wavelength of the high-reflectivity film on the optical parametric high-reflectivity mirror 211 covers the wavelength of the parametric light, meaning that the wavelength of the high-reflectivity film is comparable to the wavelengths of the signal light and idler light output by the optical parametric high-reflectivity mirror 211, and the reflectivity of the high-reflectivity film is greater than 99.8%.

[0053] In one possible implementation, the optical parametric high reflectivity mirror 211 can be a plane mirror. The optical parametric frequency conversion crystal 212 includes, but is not limited to, lithium borate (LBO) crystals, potassium titanium oxyphosphate (KTP) crystals, periodically polarized lithium niobate (PPLN) crystals, and zinc germanium phosphate (ZGP) crystals.

[0054] For example, such as Figure 2 As shown, the high-energy optical parametric oscillator's frequency conversion module 2 can be configured with two optical parametric frequency conversion modules 21. This high-energy optical parametric oscillator includes: a pump light emitting module 1 that emits two fundamental frequency pump lights with a repetition frequency of 10 kHz, a pulse width of 52 ns, and a wavelength of 2.09 µm. The optical parametric high-reflectivity mirrors 211 of the two optical parametric frequency conversion modules 21 are both plane mirrors. The surfaces of these two plane mirrors are coated with a 2.09 µm first antireflection film and a high-reflectivity film. The two parametric beams output from the two optical parametric frequency conversion modules 21 have different wavelengths, but both fall within the range of 6.45 µm-6.47 µm. Correspondingly, the wavelengths of the high-reflectivity films coated on the surfaces of the two plane mirrors are different, and the wavelengths of the high-reflectivity films coated on the surfaces of the two plane mirrors are consistent with the wavelengths of the idler light output from the optical parametric frequency conversion modules 21. Two parametric beams are combined into one beam by the subsequent spectral combining module 3 and then transmitted to the output coupling mirror 4. The output coupling mirror 4 returns part of the combined beam to the optical parametric frequency conversion module 21. In this way, the two optical parametric high reflectivity mirrors 211 cooperate with the output coupling mirror 4 to complete the oscillation of parametric beams.

[0055] Figure 3 This is the third schematic diagram of the optical path of the high-energy optical parametric oscillator provided by the present invention, as shown below. Figure 3 As shown, this high-energy optical parametric oscillator includes: a pump light emitting module 1, a frequency conversion module 2, a spectral beam combining module 3, and an output coupling mirror 4, arranged sequentially along the optical path. The functions of these optical components are the same as described above. Figure 1The functions of optical components are the same, so they will not be elaborated here.

[0056] In this embodiment, the spectral beam combining module 3 includes an optical conversion element 31 and a diffractive optical element 32 arranged sequentially along the optical path. The optical conversion element 31 is used to transmit multiple beams of parametric light to the same position of the diffractive optical element 32. The diffractive optical element 32 is used to perform spectral beam combining on the multiple beams of parametric light and transmit the resulting combined light to the output coupling mirror 4.

[0057] For example, the optical transformation element 31 is a lens, the diffractive optical element 32 is a grating, and the diffractive optical element 32 is located at the focal plane of the optical transformation element 31.

[0058] Understandably, the optical conversion element 31 can be a spherical lens or a group of spherical lenses, etc., used for light convergence. The diffractive optical element 32 is a grating that can effectively combine multiple wavelengths of light into a high-quality beam, such as a multilayer dielectric grating or a volume Bragg grating with a line density higher than 1000 lines / mm. The lens can focus multiple beams of parametric light, causing these beams to converge at the same location on the diffractive optical element 32. This helps to concentrate the dispersed beams into a smaller area, facilitating the spectral beam combining of these beams by the diffractive optical element 32. The lens can also adjust the shape of the beam to a certain extent, so that the beam entering the diffractive optical element 32 has a suitable spot size and shape to meet the requirements of the diffractive optical element 32 for spectral beam combining. The grating can recombine different wavelengths of light from multiple parametric beams based on the principle that different wavelengths of light have different diffraction angles, so that they are spatially combined into a single beam. The grating can effectively separate and recombine different wavelengths of light, thereby achieving the function of spectral beam combining, and finally combining multiple beams of parametric light into a single beam that is emitted onto the surface of the output mirror. Parametric light incident at different angles converges to the focal plane after being focused by the lens. Placing the diffractive optical element 32 at the focal plane allows for precise processing of these beams, accurately combining them in space and spectrum. This helps improve the efficiency and accuracy of beam combining, and reduces beam divergence and energy loss.

[0059] In one possible implementation, the parametric light includes a signal light and an idler light, and the output coupling mirror is coated with a second antireflection film. The second antireflection film has a transmittance of more than 95% for one of the signal light and the idler light, and a transmittance of 10% to 80% for the other.

[0060] Understandably, the second antireflective coating on the output coupling mirror partially transmits either the signal light or the idler light; that is, the portion of parametric light that does not transmit is returned to the optical parametric conversion module 21. The second antireflective coating allows as much of the selected signal light or idler light as possible to pass through, and the return ratio of the returned parametric light is set by adjusting the transmittance of the second antireflective coating.

[0061] In one possible implementation, parametric light is incident on the diffractive optical element 32 at a preset incident angle according to a preset incident angle formula, wherein the preset incident angle calculation formula is as follows:

[0062]

[0063] In the formula, The wavelength of the parametric light band, The groove spacing of the diffractive optical element 32. Angle of incidence It is the diffraction angle.

[0064] It is understandable that λ represents the wavelength of the parametric light band, which here refers to the wavelength of the signal light or idler light returning to the optical parametric conversion module 21. Within the maximum separation angle range that the grating guarantees diffraction power, the incident angle and diffraction angle of the corresponding parametric light and the grating can be determined, thereby determining the tilt angle of the diffractive optical element 32. The tilt angle is the angle between the diffraction surface of the diffractive optical element 32 and the parametric light incident on its surface. A correct tilt angle ensures that the propagation direction and energy distribution of the light meet the expected requirements, thus ensuring that within the maximum separation angle range that the grating guarantees diffraction power, the grating can most effectively separate light with different parameters (such as different wavelengths) and ensure that the diffracted light has sufficient power.

[0065] For example, such as Figure 3As shown, the high-energy optical parametric oscillator can be configured with three optical parametric conversion modules 21. This high-energy optical parametric oscillator includes: a pump light emitting module 1 that emits three fundamental frequency pump lights with a repetition frequency of 1 kHz, a pulse width of 15 ns, and a wavelength of 532 nm. The optical parametric high-reflectivity mirrors 211 in the three optical parametric conversion modules 21 are all coated with a 532 nm first antireflection film and a high-reflectivity film. The three signal lights (idle light) output by the three optical parametric conversion modules 21 have different wavelengths, but are within the range of 991 nm to 1010 nm. The wavelength of the high-reflectivity film of each optical parametric conversion module 21 is consistent with the wavelength of the signal light output by each optical parametric conversion module 21. The optical parametric conversion crystals 212 in the three optical parametric conversion modules 21 are all LBO crystals, with dimensions of 5 mm × 5 mm × 60 mm and two light-transmitting ports of 5 mm × 5 mm. All LBO crystals satisfy Type I phase matching with a matching angle θ = 90° and φ = 0°. The LBO crystals are equipped with a crystal temperature control device with an accuracy of 0.1 °C for temperature regulation. By adjusting the crystal temperature through the temperature control device, the output wavelength of the three generated signal beams λs is 991nm-1010nm, but with different wavelengths. The combined parametric light is transmitted to the output coupling mirror 4, where a portion of the combined parametric light is reflected back to the optical parametric conversion module 21 along the original path, and the remainder is output from the output coupling mirror 4. The output coupling mirror 4 is coated with a film with a predetermined reflectivity for the 991-1010nm output signal light.

[0066] Figure 4 This is the fourth schematic diagram of the optical path of the high-energy optical parametric oscillator provided by the present invention, as shown below. Figure 4 As shown, the high-energy optical parametric oscillator includes: a pump light emitting module 1, a frequency conversion module 2, a spectral beam combining module 3, and an output coupling mirror 4 arranged sequentially along the optical path.

[0067] The functions of the above optical devices are the same as those described above. Figure 1 The functions of optical components are the same, so they will not be elaborated here.

[0068] In this embodiment, the frequency conversion module 2 includes n (three or more) optical parametric frequency conversion modules 21, which are arranged in a straight line at equal intervals. Each optical parametric frequency conversion module 21 includes an optical parametric high-reflectivity mirror 211 and an optical parametric frequency conversion crystal 212 arranged sequentially along the optical path. The spectral beam combining module 3 includes an optical conversion element 31 and a diffractive optical element 32 arranged sequentially along the optical path. The functions of these optical devices are the same as described above. Figure 2 and 3 The functions of optical components are the same, so they will not be elaborated here.

[0069] Among them, multiple optical parametric frequency conversion modules 21 are arranged in parallel according to wavelength, and the multiple optical parametric frequency conversion modules 21 together generate equally spaced parallel lasers to generate parametric light with different wavelengths but located in the same band.

[0070] Understandably, a linear arrangement allows for high integration within a limited space, facilitating the construction of miniaturized optical parametric oscillators. Equally spaced arrangement helps optimize the spatial overlap of pump light and signal light in the nonlinear medium, improving conversion efficiency.

[0071] In one possible implementation, the pump light emission module 1 includes a plurality of pump laser emitters 11 corresponding one-to-one with the optical parametric frequency conversion module 21.

[0072] Understandably, the multiple optical parametric frequency conversion modules 21 and their corresponding pump laser emitters 11 provide redundancy. If one of the optical parametric frequency conversion modules 21 or the pump laser emitter 11 fails, the other components can still continue to operate, preventing a complete system failure. Furthermore, pump energy can be flexibly distributed among the different optical parametric frequency conversion modules 21 according to actual needs. In some application scenarios, certain frequency conversion modules may need to output more energy; by adjusting the power and other parameters of the corresponding pump laser emitter 11, energy can be rationally distributed among the different modules, improving energy utilization efficiency.

[0073] The mid-to-far infrared optical parametric oscillator provided in this embodiment includes the above-mentioned Figures 1 to 4 The high-energy optical parametric oscillator is similar in principle and technical effect, and will not be described in detail here.

[0074] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-energy optical parametric oscillator, characterized in that, include: The pump light emitting module, frequency conversion module, spectral beam combining module, and output coupling mirror are arranged sequentially along the optical path; among them... The pump light emitting module is used to emit multiple pump lights of preset wavelengths to the frequency conversion module; wherein, the multiple pump lights have the same wavelength. The frequency conversion module includes multiple optical parametric frequency conversion modules, which are used to convert the received pump light into parametric light. The multiple pump lights emitted by the pump light emitting module are input one-to-one to the multiple optical parametric frequency conversion modules. The wavelengths of the parametric light output by different optical parametric frequency conversion modules are different. The parametric light includes signal light and idler light. The output coupling mirror is coated with a second anti-reflection film. The second anti-reflection film has a transmittance greater than 95% for one of the signal light and the idler light, and a transmittance of 10% to 80% for the other. The spectral beam combining module is used to combine the multiple parametric beams generated by the frequency conversion module to form a combined beam, and transmit the combined beam to the output coupling mirror. The output coupling mirror is used to reflect a portion of the combined light back to each of the optical parametric frequency conversion modules to form feedback oscillation, and output the other portion of the combined light. The optical parametric frequency conversion module includes an optical parametric high reflectivity mirror and an optical parametric frequency conversion crystal arranged sequentially along the optical path. The frequency conversion module, the spectral beam combining module, and the output coupling mirror together constitute an optical parametric oscillation cavity. The spectral beam combining module includes an optical conversion element and a diffractive optical element arranged sequentially along the optical path. The optical conversion element is used to transmit multiple parametric beams to the same position of the diffractive optical element. The diffractive optical element is used to perform spectral beam combining on the multiple parametric beams and transmit the resulting combined beam to the output coupling mirror.

2. The high-energy optical parametric oscillator according to claim 1, characterized in that, The optical parametric high reflectivity mirror is coated with a first antireflection film and a high reflectivity film, wherein the first antireflection film has a transmittance of more than 95% for pump light, and the wavelength of the high reflectivity film covers the wavelength of the parametric light.

3. The high-energy optical parametric oscillator according to claim 1, characterized in that, The optical transformation element is a lens, the diffractive optical element is a grating, and the diffractive optical element is located at the focal plane of the optical transformation element.

4. The high-energy optical parametric oscillator according to claim 1, characterized in that, According to a preset incident angle formula, the parametric light is incident on the diffractive optical element at a preset incident angle, wherein the preset incident angle calculation formula is as follows: In the formula, Where is the wavelength in the parametric light band, and d is the groove spacing of the diffractive optical element. Angle of incidence It is the diffraction angle.

5. The high-energy optical parametric oscillator according to any one of claims 1 to 4, characterized in that, The pump light emission module includes multiple pump laser emitters that correspond one-to-one with the optical parametric frequency conversion module.

6. The high-energy optical parametric oscillator according to any one of claims 1 to 4, characterized in that, The optical parametric frequency conversion module has multiple optical parametric oscillation cavities arranged in a straight line with equal spacing.

7. A mid-to-far-infrared optical parametric oscillator, characterized in that, Includes the high-energy optical parametric oscillator as described in any one of claims 1 to 6.

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