Optical parametric oscillator beam quality optimization method and system based on pump pulse time domain modulation

Abstract

This disclosure provides a method and system for optimizing the beam quality of an OPO (Optimal Optical Parametric Oscillator) based on pump pulse time-domain modulation, relating to the field of laser modulation technology. The method includes: acquiring a semiconductor continuous light seed source; performing pulse modulation pre-compensation on the seed light using a signal generator and an optical modulator; amplifying the pre-compensated seed light through a fiber-solid multi-stage amplification process to obtain a near-diffraction-limited time-domain flat-top light pulse; pumping an optical parametric oscillator (OPO) with the time-domain flat-top light pulse to optimize the intracavity parametric conversion process of the OPO, thereby changing the spatial distribution characteristics of the OPO output light, outputting parametric light, and measuring the beam quality and power of the parametric light to evaluate the conversion efficiency and beam optimization effect, thus completing the beam quality optimization process of the OPO output beam. This disclosure significantly optimizes the beam quality of the parametric light output while maintaining high conversion efficiency.

Description

Technical Field

[0001] This disclosure relates to the field of laser modulation technology, specifically to an OPO beam quality optimization method and system based on pump pulse time-domain modulation. Background Technology

[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.

[0003] Mid- and short-wave infrared lasers (1-3 μm) play an irreplaceable role and have broad development potential in fields such as atmospheric remote sensing, environmental monitoring, and military optoelectronic warfare. Since the gain spectrum of most laser gain media cannot cover the mid- and short-wave infrared laser band, optical parametric oscillators (OPOs) based on nonlinear frequency conversion technology have become a crucial technique for achieving laser output in this band. Benefiting from their wide spectral coverage and wide tuning characteristics, OPOs have consistently been a hot topic in laser source research.

[0004] In the technology related to optical parametric oscillators (OPOs), two important indicators are used to measure the performance of an OPO. The first is the oscillator's conversion efficiency. Higher conversion efficiency means the oscillator can more effectively convert pump light energy into the required parametric light energy, resulting in higher energy utilization. The second indicator is the beam quality of the output parametric light, which determines the spatial distribution characteristics of the output light. Better beam quality means better spatial coherence of the output beam, and the beam will not diverge significantly over long distances. This is extremely important for long-distance applications such as atmospheric remote sensing and military optoelectronic warfare.

[0005] However, in traditional Gaussian pulse pumped optical parametric oscillators (OPOs), although the parametric conversion efficiency of the OPO can be improved with the increase of pump light power, the beam quality of the output parametric light often deteriorates rapidly due to factors such as uneven nonlinear gain distribution, inverse conversion effect, and competition of higher-order modes. This manifests as increased spot distortion, increased divergence angle, and decreased spatial coherence, which severely restricts its practical application in long-distance transmission and high-precision application scenarios.

[0006] Among the existing methods for improving beam quality, various schemes have been proposed to improve the output beam quality of OPO. Among them, the more common methods mainly revolve around the cavity structure of the optical parametric oscillator. For example, by adopting an unstable cavity structure, a non-planar ring cavity structure, or introducing a special mode selection mechanism, the intracavity mode distribution can be controlled, thereby suppressing the oscillation of higher-order transverse modes to a certain extent and improving the spatial optical field distribution of parametric light.

[0007] However, the above-mentioned schemes based on cavity structure optimization still have the following obvious limitations:

[0008] (i) On the one hand, unstable or complex cavity structures place higher demands on system stability, machining accuracy and intracavity adjustment, making system implementation more difficult;

[0009] (ii) On the other hand, such methods often require a trade-off between mode selection and energy extraction, making it difficult to achieve a synergistic improvement in beam quality while maintaining high parametric conversion efficiency. Especially under high pump power conditions, the beam quality improvement effect is limited, making it difficult to meet the application requirements of high efficiency and high beam quality at the same time. Summary of the Invention

[0010] To address the aforementioned issues, this disclosure proposes an OPO beam quality optimization method and system based on pump pulse time-domain modulation. By generating a flat-top pump pulse through pulse modulation technology, and utilizing the flat-top pump OPO to suppress non-uniform gain and inverse conversion effects during the nonlinear conversion process, the beam quality is significantly improved while maintaining high conversion efficiency.

[0011] According to some embodiments, the present disclosure adopts the following technical solutions:

[0012] An OPO beam quality optimization method based on pump pulse time-domain modulation includes:

[0013] Obtain a continuous light seed source for semiconductors;

[0014] The seed light is pre-compensated by pulse modulation using a signal generator and an optical modulator.

[0015] The pre-compensated seed light is amplified through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse.

[0016] By using time-domain flat-top optical pulse pumping of an optical parametric oscillator (OPO), the parametric conversion process within the OPO cavity is optimized, thereby altering the spatial distribution characteristics of the OPO's output light. Parametric light is output, and the beam quality and power of the parametric light are measured to evaluate the conversion efficiency and beam optimization effect, thus completing the process of optimizing the quality of the OPO's output beam.

[0017] According to some embodiments, the present disclosure adopts the following technical solutions:

[0018] An OPO beam quality optimization system based on pump pulse time-domain modulation includes:

[0019] An optical signal generation module is used to acquire a continuous semiconductor light seed source;

[0020] The pre-compensation module is used to perform pulse modulation pre-compensation on the seed light using a signal generator and an optical modulator;

[0021] The pulse generation module is used to amplify the pre-compensated seed light through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse.

[0022] The conversion optimization module is used to pump the optical parametric oscillator with a time-domain flat-top optical pulse, optimize the parametric conversion process within the optical parametric oscillator cavity, thereby changing the spatial distribution characteristics of the output light of the optical parametric oscillator, outputting parametric light, and measuring the beam quality and power of the parametric light, evaluating the conversion efficiency and beam optimization effect, and completing the quality optimization process of the output beam of the optical parametric oscillator.

[0023] According to some embodiments, the present disclosure adopts the following technical solutions:

[0024] A computer program product includes a computer program that, when executed by a processor, implements the OPO beam quality optimization method based on pump pulse time-domain modulation.

[0025] According to some embodiments, the present disclosure adopts the following technical solutions:

[0026] A non-transitory computer-readable storage medium is provided for storing computer instructions, which, when executed by a processor, implement the OPO beam quality optimization method based on pump pulse time-domain modulation.

[0027] According to some embodiments, the present disclosure adopts the following technical solutions:

[0028] An electronic device includes a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to implement the OPO beam quality optimization method based on pump pulse time-domain modulation.

[0029] Compared with the prior art, the beneficial effects of this disclosure are as follows:

[0030] This disclosure presents an OPO beam quality optimization method based on pump pulse time-domain modulation. The seed light undergoes pulse modulation pre-compensation via a signal generator and an acousto-optic or electro-optic modulator, followed by a multi-stage optical amplification system to obtain a near-diffraction-limited flat-top pump pulse (e.g., 70 mJ, 300 Hz @ 1064 nm). This flat-top pulse pump optical parametric oscillator is then used to optimize its intracavity parametric conversion process, significantly improving the beam quality of the output parametric light. This method effectively improves the spatial distribution characteristics of the OPO output light while maintaining high energy conversion efficiency, making it suitable for laser applications with high beam quality requirements.

[0031] The OPO beam quality optimization method based on pump pulse time-domain modulation disclosed herein achieves near-diffraction-limited flat-top light pulse output of nearly 100 millijoules through time-domain waveform pre-compensation modulation technology, optimizing the parametric conversion and parametric light output performance of the OPO, and significantly improving the beam quality of the parametric light output while maintaining high conversion efficiency of parametric light.

[0032] This disclosure presents an OPO beam quality optimization method based on pump pulse time-domain modulation. It generates a flat-top pump pulse using pulse modulation technology and utilizes this pulse to pump the OPO to optimize its output beam quality. Compared to traditional Gaussian pulse-pumped OPOs, the flat-top pulse has a more uniform time-domain distribution, effectively suppressing non-uniform gain and inverse conversion effects during the nonlinear conversion process, thereby significantly improving beam quality while maintaining high conversion efficiency. Attached Figure Description

[0033] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an undue limitation of this disclosure.

[0034] Figure 1 This is a schematic diagram of the time-domain flat-top pulse modulation pre-compensation amplification system and the flat-cavity OPO according to an embodiment of this disclosure;

[0035] Among them, 10 is a semiconductor continuous light seed source; 20 is an optical modulator; 30 is an optical fiber amplifier; 40 is an Nd:YVO4 end-pumped amplifier; 50 is an Nd:YAG side-pumped amplifier; 60 is an arbitrary wave signal generator; 70 is an input coupling mirror; 80 is a KTA nonlinear optical crystal; and 90 is an output coupling mirror.

[0036] Figure 2 This is a schematic diagram of the OPO simulation system interface according to an embodiment of the present disclosure;

[0037] Figure 3 The power-time quality plot of a beam from a conventional Gaussian time-domain pulse-pumped OPO.

[0038] Figure 4 The quality diagram shows the change in the spot radius of a beam from a conventional Gaussian time-domain pulse-pumped OPO as a function of distance.

[0039] Figure 5 This is a quality diagram showing the power variation over time of a beam from a flat-top time-domain pulse-pumped OPO according to an embodiment of this disclosure.

[0040] Figure 6 This is a quality diagram showing the change in the spot radius of a flat-top time-domain pulse-pumped OPO beam as a function of distance, according to an embodiment of this disclosure. Detailed Implementation

[0041] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

[0042] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] Example 1

[0045] One embodiment of this disclosure provides a method for optimizing the beam quality of an OPO beam based on pump pulse time-domain modulation, the method comprising the following steps:

[0046] Step 1: Obtain a semiconductor continuous light seed source;

[0047] Step 2: Use a signal generator and an optical modulator to perform pulse modulation pre-compensation on the seed light;

[0048] Step 3: The pre-compensated seed light is amplified through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse;

[0049] Step 4: Utilize time-domain flat-top optical pulses to pump the optical parametric oscillator (OPO), optimize the parametric conversion process within the OPO cavity, thereby altering the spatial distribution characteristics of the OPO output light. Output parametric light and measure its beam quality and power to evaluate the conversion efficiency and beam optimization effect, thus completing the quality optimization process for the OPO output beam.

[0050] As one embodiment, the OPO beam quality optimization method based on pump pulse time-domain modulation disclosed herein uses a signal generator and an acousto-optic or electro-optic modulator to perform pulse modulation pre-compensation on the seed light, followed by a multi-stage optical amplification system to obtain a near-diffraction-limited flat-top pump pulse (e.g., 70 mJ, 300 Hz @ 1064 nm). This flat-top pulse pump light parametric oscillator is then used to optimize its intracavity parametric conversion process, significantly improving the beam quality of the output parametric light. This invention effectively improves the spatial distribution characteristics of the OPO output light while maintaining high energy conversion efficiency, making it suitable for laser applications with high beam quality requirements. The specific implementation process is as follows:

[0051] Step 1: Obtain a semiconductor continuous light seed source, and use a signal generator and an optical modulator to perform pulse modulation pre-compensation on the seed light; pass the pre-compensated seed light through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse.

[0052] like Figure 1 As shown, the seed light of this disclosure is emitted by a semiconductor continuous light seed source 10, and the optical modulator 20 is an acousto-optic modulator or an electro-optic modulator. Specifically, the steps of using an arbitrary signal generator 60 and the optical modulator 20 to perform pulse modulation pre-compensation on the seed light, and then passing the pre-compensated seed light through an optical amplification system for fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top optical pulse include:

[0053] (1) Measure and analyze the electro-optic response characteristics of the acousto-optic modulator used in the embodiment, and obtain the electro-optic modulation characteristics of the acousto-optic modulator through inverse transformation and curve fitting.

[0054] (2) Analyze the time-domain pulse distortion characteristics during the optical pulse amplification process, and use the optical amplification FN equation to analyze the pre-compensation pulse required for optical pulse distortion.

[0055] (3) Combining the pre-compensation pulse and the electro-optic modulation characteristics of the acousto-optic modulator, the microwave electrical signal required for pulse pre-compensation is analyzed.

[0056] (4) Analyze the response frequency of any signal generator to determine the resolution of the microwave electrical signal. The signal generator provides an analog electrical signal output to drive the acousto-optic modulator or electro-optic modulator, including but not limited to a 100MHz analog signal generator.

[0057] (5) Analyze and determine the time delay of the electrical signals of the two acousto-optic modulators and the electrical signals required by the subsequent optical amplification power supply to ensure the synchronization of the signal modulation and optical amplification system.

[0058] (6) Perform subsequent fiber-solid multi-stage amplification to obtain a time-domain flat-top optical pulse. The energy of the time-domain flat-top pulse includes, but is not limited to, 70 mJ, the repetition frequency includes, but is not limited to, 300 Hz, and the wavelength includes, but is not limited to, 1064 nm.

[0059] Furthermore, the optical amplification system includes one or more of the following: fiber amplifier 30, end-pump module, side-pump module, and disk optical amplifier. Optical amplification is divided into single-pass amplification and dual-pass amplification. The dual-pass amplification structure requires an additional Faraday magnetorotator and polarization cube for use.

[0060] Furthermore, the optical amplification is divided into fiber amplification, Nd:YVO4 end-pumped amplifier 40 amplification, and Nd:YAG side-pumped amplifier 50 amplification. Among them, the Nd:YAG amplification requires two side-pumped modules to be used together, and a 90-degree optical rotator is used for depolarization compensation to optimize the spatial optical field distribution.

[0061] Step 2: Utilize time-domain flat-top optical pulses to pump the optical parametric oscillator (OPO), optimize the parametric conversion process within the OPO cavity, thereby altering the spatial distribution characteristics of the OPO output light. Output parametric light and measure its beam quality and power to evaluate the conversion efficiency and beam optimization effect, thus completing the quality optimization process for the OPO output beam.

[0062] First, the optical parametric oscillator consists of an input coupling mirror 70, an output coupling mirror 90, and a KTA nonlinear optical crystal 80. The input coupling mirror 70 is highly transparent to both pump and idler light, and highly reflective to the signal light. The output coupling mirror 90 is partially transparent and partially reflective to the signal light, highly transparent to the idler light, and highly reflective to the pump light, thereby achieving two-way pumping and improving the conversion efficiency of the parametric light.

[0063] The distance between the input coupling mirror 70 and the output coupling mirror 90 is slightly longer than the length of the KTA nonlinear optical crystal 80 to ensure a reduced oscillation threshold and higher conversion efficiency. The KTA nonlinear optical crystal 80 is placed in the middle of the input coupling mirror 70 and the output coupling mirror 90, and an external helium-neon laser is used to ensure the collimation of the optical parametric resonator and the pump light.

[0064] Furthermore, the nonlinear optical crystal is used to realize the nonlinear frequency transformation of the pulsed laser in the specified band; the input coupling mirror is located at the input end of the nonlinear optical crystal, used to input the pump pulsed laser, and to highly reflect one of the parametric beams; the output coupling mirror is located at the output end of the first nonlinear crystal, and together with the input coupling mirror, they form an optical parametric oscillation resonant cavity, wherein the optical parametric oscillation resonant cavity is a parallel planar cavity, but is not limited to this type of cavity structure.

[0065] Among them, the nonlinear optical crystal is KTiOAsO4 (KTA) crystal, and also includes but is not limited to ZnGeP2, PPLN, CdSe, KTiOPO4 or BaGa4Se4 crystal.

[0066] Furthermore, the specific details of optimizing the intracavity parametric conversion process of the optical parametric oscillator by using a time-domain flat-top optical pulse to pump the optical parametric oscillator, thereby altering the spatial distribution characteristics of the output light of the optical parametric oscillator, include:

[0067] (1) Use a suitable beam-shrinking system to perform beam-shrinking processing on the pump light, and analyze the temporal pulse characteristics of the pump light, such as pulse width, and the spatial optical field characteristics, such as beam quality and divergence angle, using a photoelectric probe and a beam quality analyzer.

[0068] (2) The conversion efficiency and beam quality of parametric light with pump energy were analyzed by pumping the flat short cavity OPO with time-domain Gaussian light pulse and time-domain flat-top light pulse respectively.

[0069] (3) Finally, by combining the results given by the simulation program and the experimental results, the process of performance optimization of time-domain flat-top pulse pump OPO is obtained.

[0070] The theoretical simulation results corresponding to the optimization process include pump light input parameters, OPO cavity structure parameters, parametric conversion efficiency, and parametric beam quality.

[0071] Furthermore, the output parametric light is measured, and its beam quality and power are evaluated to assess the conversion efficiency and beam optimization effect, thus completing the beam quality optimization process of the optical parametric oscillator output beam. The process of outputting parametric light and measuring its beam quality includes:

[0072] (1) The quality of the parametric beam can be directly analyzed using a beam quality analyzer, or the beam quality can be obtained by measuring the beam spot at multiple locations using a knife-edge gauge and guide rail and fitting the results.

[0073] (2) The focusing lens used for parametric light includes, but is not limited to, a focal length of 200 mm;

[0074] (3) An adjustable attenuator is used at the output end of the optical parametric oscillator to adjust the laser power of the parametric light injected into the optical parametric oscillator, including but not limited to an adjustable attenuator or a half-wave plate and a polarization cube.

[0075] Furthermore, the process of measuring the power of the parametric light includes:

[0076] (1) Use a beam splitter to separate the parametric light and the pump light;

[0077] (2) Use a photothermal power meter or energy meter to measure the power or energy of the parametric light after spectral dispersion.

[0078] As one example, conversion efficiency and beam quality assessment require the use of mathematical analysis tools Origin and MATLAB, as well as a packaged OPO simulation program.

[0079] As one embodiment, the specific working process of the OPO beam quality optimization method based on pump pulse time-domain modulation disclosed herein includes:

[0080] 1. The seed light is pre-compensated and modulated using a signal generator and an optical modulator (such as an acousto-optic or electro-optic modulator);

[0081] 2. High-energy time-domain flat-top pulses are obtained after multi-stage optical amplification (such as fiber amplification, end-pumped and side-pumped amplification);

[0082] 3. The OPO is pumped using this flat-top pulse pump, and the output light is evaluated using a beam quality analysis system.

[0083] The OPO beam quality optimization method based on pump pulse time-domain modulation disclosed herein can be applied to infrared remote sensing, environmental monitoring, or optoelectronic countermeasures systems.

[0084] Example 2

[0085] One embodiment of this disclosure provides a conventional method for Gaussian pulse-pumped OPO and beam quality analysis, mainly including:

[0086] 1. Input the experimental parameters into the simulation system, such as... Figure 2 As shown, the feasibility of the experiment was determined and the output characteristics of parametric light were obtained.

[0087] 2. By utilizing the photoelectric modulation characteristics analysis of the acousto-optic modulator and the response frequency of the signal generator, the analog modulation function of the signal generator is used to output a precise pulse pre-compensation electrical signal with a specific resolution. After being driven by the acousto-optic modulator, the signal is transmitted to the acousto-optic modulator to modulate the continuous laser output from the semiconductor seed source using a set Gaussian time-domain waveform.

[0088] 3. The modulated signal passes through the fiber optic amplification stage, and the output power of the fiber optic amplification stage LD is precisely controlled to ensure that the nonlinear effects and spontaneous emission in the fiber do not affect the time-domain pulse modulation. The signal is then coupled out through fiber optic filtering devices and fiber optic collimators.

[0089] 4. End-pumped optical amplification is performed using a high-power 808nm or 878nm LD pump source and an Nd:YVO4 gain crystal. The optical amplification structure is divided into single-pass and dual-pass amplification. For single-pass amplification, the overlap between the pump LD and the signal light must be ensured to improve amplification efficiency. Dual-pass amplification requires additional Faraday magnetorotators and polarization cubic structures, while also ensuring the consistency of the seed light's round-trip travel within the gain crystal.

[0090] 5. Side-pumped light amplification was performed using an Nd:YAG side-pumping module to obtain near-diffraction-limited Gaussian pulsed light output (70mJ, 300Hz@1064nm). Two side-pumping modules were required for matching, and a 90-degree optical rotator was used to perform depolarization compensation on the side-pumping module to reduce the influence of depolarization on the spatial distribution of the output light.

[0091] 6. The Gaussian pump pulse laser is guided to the input coupling mirror, where it is converted into signal light and idler light by the nonlinear crystal pump laser, and then guided to the output coupling mirror; the output coupling mirror is used to output the signal light and idler light. Finally, the conversion efficiency is detected using an optical power meter, and the output beam quality is measured and analyzed using a beam quality analyzer. The results are as follows: Figure 3 , Figure 4 As shown.

[0092] Example 3

[0093] One embodiment of this disclosure provides a method for improving and optimizing the beam quality of an optical parametric oscillator (OPO) by pumping a time-domain flat-top pulse waveform, namely, the OPO beam quality optimization method based on pump pulse time-domain modulation of this disclosure, which mainly includes the following steps:

[0094] 1. Input the experimental parameters into the simulation system, determine the feasibility of the experiment and obtain the output characteristics of parametric light, and compare the simulation results of time-domain Gaussian pulse pumping OPO to analyze the optimization effect.

[0095] 2. By using the photoelectric modulation characteristics analysis of the acousto-optic modulator and the response frequency of the signal generator, the analog modulation function of the signal generator is used to output a precise pulse pre-compensation electrical signal with a specific resolution. After being driven by the acousto-optic modulator, the signal is transmitted to the acousto-optic modulator to perform a set time-domain flat-top waveform pre-compensation modulation on the continuous laser output from the semiconductor seed source.

[0096] 3. The modulated signal passes through the fiber optic amplification stage, and the output power of the fiber optic amplification stage LD is precisely controlled to ensure that the nonlinear effects and spontaneous emission in the fiber do not affect the time-domain pulse modulation. The signal is then coupled out through fiber optic filtering devices and fiber optic collimators.

[0097] 4. End-pumped optical amplification is performed using high-power 808nm and 878nm LD pump sources and an Nd:YVO4 gain crystal. The optical amplification structure is divided into single-pass and dual-pass amplification. The single-pass amplification structure must ensure the overlap between the pump LD and the signal light to improve amplification efficiency. The dual-pass amplification structure requires additional Faraday magnetorotators and polarization cubic structures, while also ensuring the consistency of the seed light's round-trip travel within the gain crystal.

[0098] 5. Side-pumped light amplification was performed using an Nd:YAG side-pumping module to obtain near-diffraction-limited Gaussian pulsed light output (70mJ, 300Hz@1064nm). Two side-pumping modules were required for matching, and a 90-degree optical rotator was used to perform depolarization compensation on the side-pumping module to reduce the influence of depolarization on the spatial distribution of the output light.

[0099] 6. The flat-top pump pulse laser is guided to the input coupling mirror, where it is converted into signal light and idler light by the nonlinear crystal pump laser, and then guided to the output coupling mirror; the output coupling mirror is used to output the signal light and idler light. Finally, the conversion efficiency is detected using an optical power meter, and the output beam quality is measured and analyzed using a beam quality analyzer. The results are as follows: Figure 5 , Figure 6 As shown.

[0100] Compared with the Gaussian pulse pumped OPO scheme in Embodiment 2, this embodiment achieves a near-diffraction-limited flat-top light pulse output of nearly 100 millijoules through time-domain waveform pre-compensation modulation technology, optimizing the parametric conversion and parametric light output performance of the OPO, and significantly improving the beam quality of the parametric light output while maintaining high conversion efficiency of parametric light.

[0101] The time-domain flat-top pulse modulation method proposed in this disclosure is not only applicable to 1064nm pump sources, but can also be extended to other bands; the pulse width of the time-domain flat-top pulse is not limited to a single pulse width, such as 100 ns, and the pulse modulation width can be selected according to actual needs; the nonlinear crystal used is not limited to KTA, and other crystal materials can be selected according to actual wavelength requirements; the OPO cavity structure adopted is not limited to flat short cavity single (double) pass structure.

[0102] Example 4

[0103] One embodiment of this disclosure provides an OPO beam quality optimization system based on pump pulse time-domain modulation, comprising:

[0104] An optical signal generation module is used to acquire a continuous semiconductor light seed source;

[0105] The pre-compensation module is used to perform pulse modulation pre-compensation on the seed light using a signal generator and an optical modulator;

[0106] The pulse generation module is used to amplify the pre-compensated seed light through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse.

[0107] The conversion optimization module is used to pump the optical parametric oscillator with a time-domain flat-top optical pulse, optimize the parametric conversion process within the optical parametric oscillator cavity, thereby changing the spatial distribution characteristics of the output light of the optical parametric oscillator, outputting parametric light, and measuring the beam quality and power of the parametric light, evaluating the conversion efficiency and beam optimization effect, and completing the quality optimization process of the output beam of the optical parametric oscillator.

[0108] Example 5

[0109] One embodiment of this disclosure provides a computer program product, including a computer program that, when executed by a processor, implements the OPO beam quality optimization method based on pump pulse time-domain modulation.

[0110] Example 6

[0111] One embodiment of this disclosure provides a non-transitory computer-readable storage medium for storing computer instructions. When these computer instructions are executed by a processor, they implement the OPO beam quality optimization method based on pump pulse time-domain modulation.

[0112] Example 7

[0113] One embodiment of this disclosure provides an electronic device, including a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to implement the OPO beam quality optimization method based on pump pulse time-domain modulation.

[0114] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0115] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0116] While the specific embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of this disclosure. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of this disclosure are still within the scope of protection of this disclosure.

Claims

1. A method for optimizing the beam quality of an OPO beam based on pump pulse time-domain modulation, characterized in that, include: Obtain a continuous light seed source for semiconductors; The seed light is pre-compensated by pulse modulation using a signal generator and an optical modulator, including: The electro-optic response characteristics of the acousto-optic modulator used were measured and analyzed, and the electro-optic modulation characteristics of the acousto-optic modulator were obtained by inverse transformation and curve fitting. The temporal pulse distortion characteristics during optical pulse amplification are analyzed, and the pre-compensation pulse required for optical pulse distortion is analyzed using the FN equation for optical amplification. By combining the pre-compensation pulse and the electro-optic modulation characteristics of the acousto-optic modulator, the microwave electrical signal required for pulse pre-compensation is analyzed. Analyze the response frequency of any signal generator to determine the resolution of the microwave signal; The pre-compensated seed light is amplified through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse. By using time-domain flat-top optical pulse pumping of an optical parametric oscillator (OPO), the parametric conversion process within the OPO cavity is optimized, thereby altering the spatial distribution characteristics of the OPO's output light. Parametric light is output, and the beam quality and power of the parametric light are measured to evaluate the conversion efficiency and beam optimization effect, thus completing the process of optimizing the quality of the OPO's output beam.

2. The OPO beam quality optimization method based on pump pulse time-domain modulation as described in claim 1, characterized in that, The optical modulator is an acousto-optic modulator or an electro-optic modulator.

3. The OPO beam quality optimization method based on pump pulse time-domain modulation as described in claim 1, characterized in that, The process of amplifying the pre-compensated seed light through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse includes: Analyze and determine the time delay of the electrical signals required by the acousto-optic modulator and the optical amplifier power supply to ensure the synchronization of the signal modulation and optical amplification systems. Subsequent fiber-solid multi-stage amplification was performed to obtain a time-domain flat-top optical pulse; Optical amplification includes single-pass amplification and double-pass amplification.

4. The OPO beam quality optimization method based on pump pulse time-domain modulation as described in claim 1, characterized in that, The optical parametric oscillator consists of an input coupling mirror, an output coupling mirror, and a nonlinear optical crystal. The input coupling mirror is highly transparent to pump light and idler light, and highly reflective to signal light. The output coupling mirror is semi-transparent and semi-reflective to signal light, highly transparent to idler light, and highly reflective to pump light, so as to achieve two-way pumping and improve the conversion efficiency of parametric light.

5. The OPO beam quality optimization method based on pump pulse time-domain modulation as described in claim 1, characterized in that, Measuring the beam quality of parametric light includes: The quality of parametric beams can be directly analyzed using a beam quality analyzer, or the beam quality can be obtained by measuring the beam spot at multiple locations using a knife-edge gauge and guide rail and fitting the results. Focusing lenses used for parametric light include, but are not limited to, lenses with a focal length of 200 mm. An adjustable attenuator is used at the output end of the optical parametric oscillator to adjust the laser power of the parametric light injected into the optical parametric oscillator.

6. An OPO beam quality optimization system based on pump pulse time-domain modulation, characterized in that, include: An optical signal generation module is used to acquire a continuous semiconductor light seed source; The pre-compensation module, used to perform pulse modulation pre-compensation on the seed light using a signal generator and an optical modulator, includes: The electro-optic response characteristics of the acousto-optic modulator used were measured and analyzed, and the electro-optic modulation characteristics of the acousto-optic modulator were obtained by inverse transformation and curve fitting. The temporal pulse distortion characteristics during optical pulse amplification are analyzed, and the pre-compensation pulse required for optical pulse distortion is analyzed using the FN equation for optical amplification. By combining the pre-compensation pulse and the electro-optic modulation characteristics of the acousto-optic modulator, the microwave electrical signal required for pulse pre-compensation is analyzed. Analyze the response frequency of any signal generator to determine the resolution of the microwave signal; The pulse generation module is used to amplify the pre-compensated seed light through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse. The conversion optimization module is used to pump the optical parametric oscillator with a time-domain flat-top optical pulse, optimize the parametric conversion process within the optical parametric oscillator cavity, thereby changing the spatial distribution characteristics of the output light of the optical parametric oscillator, outputting parametric light, and measuring the beam quality and power of the parametric light, evaluating the conversion efficiency and beam optimization effect, and completing the quality optimization process of the output beam of the optical parametric oscillator.

7. The OPO beam quality optimization system based on pump pulse time-domain modulation as described in claim 6, characterized in that, The optical modulator is an acousto-optic modulator or an electro-optic modulator.

8. The OPO beam quality optimization system based on pump pulse time-domain modulation as described in claim 6, characterized in that, The process of amplifying the pre-compensated seed light through fiber-solid multi-stage amplification to obtain a near-diffraction-limited time-domain flat-top light pulse includes: Analyze and determine the time delay of the electrical signals required by the acousto-optic modulator and the optical amplifier power supply to ensure the synchronization of the signal modulation and optical amplification systems. Subsequent fiber-solid multi-stage amplification was performed to obtain a time-domain flat-top optical pulse; Optical amplification includes single-pass amplification and double-pass amplification.

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