High-repetition-rate laser resonator with piezoelectric actuation and pulse locking

Abstract

The application discloses a high-repetition-frequency laser resonant cavity with a piezoelectric driving function and a pulse locking device. In the resonant cavity, a stacked piezoelectric actuator is subjected to a first adhesion process with a first gasket and a second gasket at both ends, a first organic glass and a second organic glass are subjected to a second adhesion process with the other sides of the first gasket and the second gasket, and a combination based on the stacked piezoelectric actuator is formed; a dielectric film is arranged on the end face of a third plug; a gain optical fiber is inserted and passes through a first plug, the combination based on the stacked piezoelectric actuator and a second plug connected in sequence; the end face of the first plug is butted against a semiconductor saturable absorber mirror, and the end face of the second plug is butted against the dielectric film. The application overcomes the problem of repetition frequency drift in a centimeter-level resonant cavity.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, specifically relating to a high-repetition-rate laser resonator with piezoelectric actuation function and a pulse locking device. Background Technology

[0002] Optical frequency combs (hereinafter referred to as "optical combs") possess advantages such as narrow pulse width, high precision, and high stability, playing a crucial role in optical frequency measurement, frequency synthesis, and high-precision optical clocks, especially showing broad application prospects in astronomical observation and precision spectroscopy. Early optical combs were primarily built using bulky and complex Ti:sapphire femtosecond lasers and all-solid-state lasers, making them unsuitable for applications requiring considerations of heat dissipation, cost, and miniaturization. In recent years, the rapidly developing mode-locked fiber lasers, with their compact structure, low cost, and portability, have gradually become an important component in optical comb construction, significantly reducing the spatial volume of optical comb systems and improving their overall flexibility. The pulse repetition frequency of an optical comb determines its "comb tooth" spacing, and increasing the repetition frequency results in a larger longitudinal mode spacing, significantly improving the acquisition rate of detection instruments. The high repetition frequency characteristics of mode-locked fiber lasers make them a powerful tool for researching high-precision lidar and precision laser spectroscopy, and have gradually become an important development direction for optical combs.

[0003] High repetition rate (HRPR) mode-locked fiber lasers are susceptible to external factors such as ambient temperature and humidity during free operation. This is especially true in the resonant cavity of the laser seed source, which is highly sensitive to dust, noise, and mechanical disturbances, leading to unstable drift in the repetition frequency. Therefore, locking the repetition frequency is crucial for high-performance HPR mode-locked fiber lasers. The repetition frequency of a laser is primarily related to the refractive index of the medium within the resonant cavity and the cavity length. In practical applications, compared to methods such as using electro-optic modulators to change the refractive index, adjusting the cavity length by controlling the extension and retraction of a piezoelectric actuator is a common method for achieving repetition frequency locking. Attaching the fiber within the laser resonant cavity to the surface of a block-shaped piezoelectric actuator can achieve repetition frequency locking, as illustrated in CN113835241A, which uses piezoelectric ceramics with different resonant frequencies to control the repetition frequency. However, the repetition frequency achieved by this experimental setup is only in the MHz range, limiting the laser output repetition frequency and making it unsuitable for generating ultrashort fiber resonant cavities (cavity length <10cm) with GHz repetition frequencies. Furthermore, constructing a resonant cavity using other types of piezoelectric actuators typically requires a matching external structural component to ensure the proper functioning of the piezoelectric actuator, which significantly impacts the overall performance of the resonant cavity. Summary of the Invention

[0004] The purpose of this invention is to provide a high repetition rate laser resonator and pulse locking device with piezoelectric actuation function. By designing a high repetition rate laser resonator structure with piezoelectric actuation function, the length of the optical fiber in the resonator is controlled by the expansion and contraction of stacked piezoelectric actuators, thereby achieving repetition frequency locking of the GHz mode-locked fiber laser and improving its frequency stability and reliability.

[0005] The objective of this invention is achieved by at least one of the following technical solutions.

[0006] A high-repetition-rate laser resonant cavity with piezoelectric actuation function includes a first ferrule, a second ferrule, a first plexiglass, a second plexiglass, a first spacer, a second spacer, a gain fiber, a semiconductor saturable absorber mirror, a dielectric film, a third ferrule, and a stacked piezoelectric actuator.

[0007] In this process, the stacked piezoelectric actuator undergoes a first bonding process with the first and second gaskets at both ends, and then the first and second acrylic glass are bonded to the other sides of the first and second gaskets, respectively, to form a composite body based on the stacked piezoelectric actuator. A dielectric film is disposed on the end face of the third ferrule. The gain fiber is inserted into and passes through the first ferrule, the composite body based on the stacked piezoelectric actuator, and the second ferrule, which are connected in sequence. The end face of the first ferrule is aligned with the semiconductor saturable absorber mirror, and the end face of the second ferrule is aligned with the dielectric film.

[0008] Furthermore, the end faces of the first, second, and third ferrules all need to be polished first.

[0009] Furthermore, the gain fiber has a high gain coefficient greater than 1 dB / cm to achieve mode-locked pulse output at a GHz repetition frequency.

[0010] The semiconductor saturable absorber mirror serves as a mode-locking element in the resonant cavity structure. It not only has saturable absorption characteristics but also laser reflection characteristics, which greatly simplifies the structure of the resonant cavity.

[0011] Furthermore, the gain fiber includes thulium-doped silica fiber, ytterbium-doped silica fiber, or erbium-ytterbium co-doped phosphate fiber.

[0012] Furthermore, the dielectric film has a reflectivity of greater than 80% for signal light and a transmittance of greater than 80% for pump light.

[0013] Furthermore, the first and second gaskets are made of insulating material, and their surface dimensions are matched to those of the piezoelectric actuator.

[0014] Furthermore, the stacked piezoelectric actuator is composed of one or more single-layer annular piezoelectric ceramics stacked together, with positive and negative terminals led out on both sides, and has a nominal stroke range of more than 5 μm.

[0015] The high-repetition-rate laser resonator structure with piezoelectric actuation function is a Fabry-Perot cavity.

[0016] A high-repetition-rate laser pulse locking device includes a pump source, a wavelength division multiplexer, an isolator, a coupler, a photodetector, a phase-locked loop feedback circuit, and a high-repetition-rate laser resonant cavity with piezoelectric actuation function as described in any one of claims 1-5.

[0017] In this system, the emission wavelength of the pump source is matched with the pump absorption wavelength of the gain fiber in the high-repetition-rate laser resonant cavity; the wavelength division multiplexer is connected to the pigtail of the third ferrule in the high-repetition-rate laser resonant cavity; the pump end of the wavelength division multiplexer is connected to the pump source, and the signal end is connected to the isolator; the isolator is connected to the coupler; one end of the coupler directly outputs the high-repetition-rate mode-locked pulse, and the other end is input to the photodetector; the photodetector inputs the detected and converted signal to the phase-locked loop feedback circuit, and then promptly feeds back the error signal to the stacked piezoelectric actuator in the high-repetition-rate laser resonant cavity. By adjusting the length of the high-repetition-rate laser resonant cavity, the repetition frequency is locked.

[0018] Furthermore, the phase-locked loop feedback circuit is connected to the positive and negative terminals of the stacked piezoelectric actuator in the high-repetition-rate laser resonant cavity, and generates an error signal based on the converted electrical signal detected by the photodetector, which is then fed back to the stacked piezoelectric actuator in the high-repetition-rate laser resonant cavity.

[0019] Furthermore, the stacked piezoelectric actuators in the high-repetition-rate laser resonant cavity generate error signal responses to the phase-locked loop feedback circuit and extend and retract in a direction parallel to the surface of the stacked piezoelectric actuators, thereby stretching the gain fiber in the high-repetition-rate laser resonant cavity, so that the repetition frequency of the high-repetition-rate laser resonant cavity is consistent with the reference frequency, thus achieving the locking of the high-repetition-rate laser pulse repetition frequency.

[0020] Compared with existing technologies, the advantages of this invention are:

[0021] This invention provides a high-repetition-rate laser resonator with piezoelectric actuation function and a pulse locking device. Targeting GHz mode-locked fiber lasers, this invention designs a high-repetition-rate laser resonator structure with piezoelectric actuation function, which combines integration and unification. It not only plays an important role in protecting the resonator but also overcomes the problem of repetition frequency drift within the centimeter-scale resonator, achieving stable mode-locked pulse output at GHz repetition frequency. Attached Figure Description

[0022] Figure 1A schematic diagram of a high-repetition-rate laser resonator structure with piezoelectric actuation function is provided for an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of a high-repetition-rate laser pulse locking device provided in an embodiment of the present invention;

[0024] Figure 3 The static response curve of the stacked piezoelectric actuator provided in the embodiment of the present invention;

[0025] Figure 4 The dynamic response curve of the stacked piezoelectric actuator provided in the embodiment of the present invention;

[0026] Figure 5 The diagram shows the phase noise curves before and after repetition frequency locking of a high repetition rate laser pulse locking device provided in an embodiment of the present invention.

[0027] Figure 6 The graph shows the time jitter curves before and after the repetition frequency is locked in a high-repetition-rate laser pulse locking device provided in an embodiment of the present invention. Detailed Implementation

[0028] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Example 1:

[0030] A high-repetition-rate laser resonant cavity with piezoelectric actuation function includes a first ferrule 1, a second ferrule 2, a first plexiglass 3, a second plexiglass 4, a first spacer 5, a second spacer 6, a gain fiber 7, a semiconductor saturable absorber mirror 8, a dielectric film 9, a third ferrule 10, and a stacked piezoelectric actuator 11.

[0031] In this process, the stacked piezoelectric actuator 11 undergoes a first bonding process with the first gasket 5 and the second gasket 6 at both ends, and then the first plexiglass 3 and the second plexiglass 4 undergo a second bonding process with the other side of the first gasket 5 and the second gasket 6, respectively, to form a composite body based on the stacked piezoelectric actuator; the dielectric film 9 is disposed on the end face of the third ferrule 10; the gain fiber 7 is inserted into and passes through the first ferrule 1, the composite body based on the stacked piezoelectric actuator, and the second ferrule 2 connected in sequence; the end face of the first ferrule 1 is connected to the semiconductor saturable absorber mirror 8, and the end face of the second ferrule 2 is connected to the dielectric film 9.

[0032] Furthermore, the end faces of the first insert 1, the second insert 2, and the third insert 10 all need to be polished first.

[0033] Furthermore, the gain fiber 7 has a high gain coefficient greater than 1 dB / cm to achieve mode-locked pulse output at a GHz repetition frequency.

[0034] The semiconductor saturable absorber mirror 8 serves as a mode-locking element in the resonant cavity structure. It not only has saturable absorption characteristics but also laser reflection characteristics, which greatly simplifies the structure of the resonant cavity.

[0035] Furthermore, the gain fiber 7 includes thulium-doped silica fiber, ytterbium-doped silica fiber, or erbium-ytterbium co-doped phosphate fiber.

[0036] Furthermore, the dielectric film 9 has a reflectivity of more than 80% for signal light and a transmittance of more than 80% for pump light.

[0037] Furthermore, the first gasket 5 and the second gasket 6 are made of insulating material, and their surface dimensions are matched to those of the piezoelectric actuator.

[0038] Furthermore, the stacked piezoelectric actuator 11 is composed of one or more single-layer annular piezoelectric ceramics stacked together, with positive and negative terminals led out on both sides, and has a nominal stroke range of more than 5 μm.

[0039] The high-repetition-rate laser resonator structure with piezoelectric actuation function is a Fabry-Perot cavity.

[0040] To achieve mode-locked pulse output with a repetition rate greater than 1 GHz, the length of the high-repetition-rate laser resonator is typically required to be less than 10 cm, and the length of the gain fiber 7 must be minimized as much as possible. Therefore, the gain fiber 7 needs to have a high gain coefficient to achieve mode-locked pulse output with a GHz repetition rate. The two ends of the gain fiber 7 are tightly bonded to the first ferrule 1 and the second ferrule 2, which have matching aperture sizes, using fiber adhesive. After assembly, the end faces of the first ferrule 1 and the second ferrule 2 need to be polished.

[0041] Compared to other types of piezoelectric actuators, such as those used in block-type resonant cavity construction, the high-repetition-rate laser resonant cavity structure with piezoelectric actuation provided by this invention offers advantages in fiber end-face polishing, thus improving the cavity's lifespan. Furthermore, constructing a resonant cavity using other types of piezoelectric actuators typically requires a matching structural component to ensure the actuator's proper operation, which significantly impacts the overall performance of the resonant cavity. The aforementioned high-repetition-rate laser resonant cavity with piezoelectric actuation offers advantages in integration and unification, making it highly suitable for application in high-repetition-rate mode-locked fiber lasers.

[0042] Figure 1 This is a structural diagram of a high-repetition-rate laser resonator with piezoelectric actuation function in this embodiment. The gain fiber is made of thulium-doped silica fiber, with a core diameter of 5.5 μm and a cladding diameter of 125 μm. The thickness of the first spacer 5 and the second spacer 6 is 1 mm; the length of the first acrylic glass 3 and the second acrylic glass 4 is 0.5 cm. The stacked piezoelectric actuator 11 is composed of six single-layer circular piezoelectric ceramics stacked together, with positive and negative terminals led out from both sides and connected to the phase-locked loop feedback circuit; the outer diameter of the stacked piezoelectric actuator 11 is 8 mm, the inner diameter is 4.5 mm, and the total length is 16 mm. The dielectric film 9 has a reflection range of 1850 nm to 2050 nm, with a reflectivity of greater than 90% for signal light; and a transmission range of 1450 nm to 1650 nm, with a transmittance of greater than 95% for pump light. The semiconductor saturable absorber mirror 8 has an area of ​​1×1 mm, a thickness of 450 μm, a recovery time of 10 ps, ​​a modulation depth of 12%, and a saturation energy of 65 μJ / cm². 2 This technology was used to construct a high-repetition-rate laser resonant cavity based on a stacked piezoelectric actuator. The cavity length was 3.8 cm, and the corresponding pulse fundamental repetition frequency was 2.7 GHz.

[0043] The high repetition rate laser resonator of this embodiment is applied to a laser pulse locking device. The pump source 12 is a 1570nm continuous light laser, which can generate a 1950nm high repetition rate mode-locked pulse output with repetition frequency locked.

[0044] A high-repetition-rate laser pulse locking device, such as Figure 2 As shown, it includes a pump source 12, a wavelength division multiplexer 13, an isolator 14, a coupler 15, a photodetector 16, a phase-locked loop feedback circuit 17, and a high-repetition-rate laser resonator with piezoelectric actuation function as described in any one of claims 1-5.

[0045] In this system, the emission wavelength of the pump source 12 is matched with the pump absorption wavelength of the gain fiber 7 in the high repetition rate laser resonant cavity; the wavelength division multiplexer 13 is connected to the pigtail of the third ferrule 10 in the high repetition rate laser resonant cavity; the pump end of the wavelength division multiplexer 13 is connected to the pump source 12, and the signal end is connected to the isolator 14; the isolator 14 is connected to the coupler 15; one end of the coupler 15 directly outputs the high repetition rate mode-locked pulse, and the other end is input to the photodetector 16; the photodetector 16 inputs the detected and converted signal to the phase-locked loop feedback circuit 17, and then promptly feeds back the error signal to the stacked piezoelectric actuator 11 in the high repetition rate laser resonant cavity, thereby achieving frequency locking by adjusting the length of the high repetition rate laser resonant cavity.

[0046] Furthermore, the phase-locked loop feedback circuit 17 is connected to the positive and negative terminals of the stacked piezoelectric actuator 11 in the high-repetition-rate laser resonant cavity, and generates an error signal based on the converted electrical signal detected by the photodetector 16, which is then fed back to the stacked piezoelectric actuator 11 in the high-repetition-rate laser resonant cavity.

[0047] Furthermore, the stacked piezoelectric actuator 11 in the high-repetition-rate laser resonant cavity generates an error signal response to the phase-locked loop feedback circuit 17 and extends and retracts in a direction parallel to the surface of the stacked piezoelectric actuator 11, thereby causing the gain fiber 7 in the high-repetition-rate laser resonant cavity to stretch, so that the repetition frequency of the high-repetition-rate laser resonant cavity is consistent with the reference frequency, thus achieving the locking of the high-repetition-rate laser pulse repetition frequency.

[0048] The static response curve of the stacked piezoelectric actuator is as follows: Figure 3 As shown. Measurement results show that the frequency shift is linearly related to the voltage within the range of 0–5V, thus the static frequency tuning coefficient of the stacked piezoelectric actuator in this embodiment is 1.02kHz / V. The dynamic response curve of the stacked piezoelectric actuator is shown below. Figure 4 As shown. Measurement results show that when the applied modulation frequency is below 1kHz, the intensity response of the stacked piezoelectric actuator does not change significantly; however, when the modulation frequency is above 1kHz, the relative intensity response of the stacked piezoelectric actuator gradually decreases, indicating that the dynamic response bandwidth of the stacked piezoelectric actuator is approximately 1kHz.

[0049] When the laser resonator cavity operates freely, the repetition frequency of the output pulse exhibits a significant frequency shift. The resonator cavity is even more sensitive to external factors such as ambient temperature; slight disturbances can cause substantial mode-locking jitter, thus introducing significant phase noise. The phase noise and time jitter curves of the high-repetition-rate laser pulse locking device in this embodiment before and after repetition frequency locking are shown below. Figure 5 , Figure 6 As shown in the figure, the measurement results show that when the pulse repetition frequency is locked, the phase noise decreases from -19dBc / Hz to -60dBc / Hz at an offset frequency of 10Hz; and the cumulative pulse time jitter decreases from 16.14ps to 0.67ps in the range of 10Hz to 1MHz.

[0050] Example 2:

[0051] The high-repetition-rate laser resonator with piezoelectric actuation function provided in this embodiment has the same structure as the resonator in Embodiment 1, both being typical Fabry-Perot cavities. However, the material parameters, such as the intracavity gain fiber, are different. The gain fiber is made of ytterbium-doped silica fiber; the structural parameters of the ferrule match those of the gain fiber. The thickness of the first spacer 5 and the second spacer 6 is 1 mm; the length of the first acrylic glass 3 and the second acrylic glass 4 is 3.6 cm. The stacked piezoelectric actuator 11 is composed of six single-layer circular piezoelectric ceramics stacked together, with positive and negative terminals led out from both sides and connected to the phase-locked loop feedback circuit; the outer diameter of the stacked piezoelectric actuator 11 is 8 mm, the inner diameter is 4.5 mm, and the total length is 16 mm. The dielectric film 9 has a reflectivity of 97% for signal light and a transmittance of 96% for pump light. The semiconductor saturable absorber mirror 8 has an area of ​​1 × 1 mm, a thickness of 450 μm, a recovery time of 1 ps, a modulation depth of 5%, and a saturation energy of 40 μJ / cm². 2 This technology is used to construct a high-repetition-rate laser resonant cavity based on a stacked piezoelectric actuator. The cavity is 10 cm long and corresponds to a pulse fundamental repetition frequency of 1.06 GHz. Applying this high-repetition-rate laser resonant cavity to a laser pulse locking device, with a 976 nm laser diode as the pump source 12, a 1064 nm high-repetition-rate mode-locked pulse output with repetition frequency locked can be generated.

[0052] Example 3:

[0053] The high-repetition-rate laser resonator with piezoelectric actuation function provided in this embodiment differs from the previous embodiments in that the gain fiber is an erbium-ytterbium co-doped phosphate fiber; the structural parameters of the ferrule match the structural parameters of the gain fiber. The thickness of the first spacer 5 and the second spacer 6 is 1 mm; the length of the first acrylic glass 3 and the second acrylic glass 4 is 3 mm. The stacked piezoelectric actuator 11 is composed of a single-layer circular piezoelectric ceramic stack, with positive and negative terminals led out from both sides and connected to the phase-locked loop feedback circuit; the outer diameter of the stacked piezoelectric actuator 11 is 8 mm, the inner diameter is 4.5 mm, and the total length is 3 mm. The dielectric film 9 has a reflectivity greater than 99% for signal light and a transmittance greater than 99% for pump light. The semiconductor saturable absorber mirror 8 has an area of ​​1 × 1 mm, a thickness of 450 μm, a recovery time of 5 ps, a modulation depth of 4%, and a saturation energy of 15 μJ / cm². 2 This technology is used to construct a high-repetition-rate laser resonant cavity based on a stacked piezoelectric actuator. The cavity length is 2.1 cm, and the corresponding pulse fundamental repetition frequency is 4.6 GHz. Applying this high-repetition-rate laser resonant cavity to a laser pulse locking device, with the pump source 12 being a 974 nm laser diode, it can generate a 1565 nm high-repetition-rate mode-locked pulse output with repetition frequency locked.

[0054] This invention utilizes the piezoelectric actuation function of stacked piezoelectric actuators to construct a high repetition rate (PRR) resonant cavity on the centimeter scale. In the overall structure of the resonant cavity, the lengths of the stacked piezoelectric actuators, the first acrylic glass, and the second acrylic glass are determined by the desired pulse repetition frequency, thus allowing for flexible mode-locked pulse output with repetition frequencies >1 GHz. Furthermore, depending on the structural parameters of the gain fiber within the cavity, high PPR mode-locked pulses with center wavelengths of 1064 nm, 1565 nm, and 1950 nm can be output. Applying this high PPR laser resonant cavity with piezoelectric actuation function to a laser pulse locking device enables the locking of the high PPR laser pulse repetition frequency.

[0055] This invention targets GHz repetition rate mode-locked fiber lasers. By designing a high repetition rate laser resonant cavity structure with piezoelectric actuation function, which combines integration and unification, it overcomes the problem of repetition rate drift in centimeter-scale resonant cavities, realizes the locking of the repetition rate of the mode-locked laser, and improves its frequency stability and reliability.

[0056] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A high-repetition-rate laser resonator with piezoelectric actuation function, characterized in that, The assembly includes a first ferrule (1), a second ferrule (2), a first acrylic glass (3), a second acrylic glass (4), a first gasket (5), a second gasket (6), a gain fiber (7), a semiconductor saturable absorber mirror (8), a dielectric film (9), a third ferrule (10), and a stacked piezoelectric actuator (11). The stacked piezoelectric actuator (11) is first bonded to the first gasket (5) and the second gasket (6) at both ends, and then the first acrylic glass (3) and the second acrylic glass (4) are bonded to the other side of the first gasket (5) and the second gasket (6) a second time. The stacked piezoelectric actuator (11) is formed by stacking multiple single-layer circular piezoelectric ceramics and has a nominal stroke range greater than 5 μm. The gain fiber (7) is arranged in a combination based on a stacked piezoelectric actuator. The dielectric film (9) is disposed on the end face of the third ferrule (10). The gain fiber (7) is inserted into and passes through the first ferrule (1), the combination based on the stacked piezoelectric actuator, and the second ferrule (2) are connected in sequence. The end face of the first ferrule (1) is connected to the semiconductor saturable absorber mirror (8), and the end face of the second ferrule (2) is connected to the dielectric film (9). The stacked piezoelectric actuator (11) is composed of multiple single-layer circular piezoelectric ceramics stacked together. The gain coefficient of the gain fiber (7) is greater than 1 dB / cm.

2. The high-repetition-rate laser resonator with piezoelectric actuation function according to claim 1, characterized in that, The end faces of the first ferrule (1), the second ferrule (2) and the third ferrule (10) must be polished first.

3. The high-repetition-rate laser resonator with piezoelectric actuation function according to claim 1, characterized in that, The gain fiber (7) includes thulium-doped silica fiber, ytterbium-doped silica fiber, or erbium-ytterbium co-doped phosphate fiber.

4. The high-repetition-rate laser resonator with piezoelectric actuation function according to claim 1, characterized in that, The dielectric film (9) has a reflectivity of more than 80% for signal light and a transmittance of more than 80% for pump light.

5. The high-repetition-rate laser resonator with piezoelectric actuation function according to claim 1, characterized in that, The first gasket (5) and the second gasket (6) are made of insulating material and their surface dimensions are matched to those of the piezoelectric actuator.

6. A high-repetition-rate laser pulse locking device, characterized in that, It includes a pump source (12), a wavelength division multiplexer (13), an isolator (14), a coupler (15), a photodetector (16), a phase-locked loop feedback circuit (17), and a high-repetition-rate laser resonator with piezoelectric actuation function as described in any one of claims 1-5; Among them, the emission wavelength of the pump source (12) is matched with the pump absorption wavelength of the gain fiber (7) in the high repetition rate laser resonant cavity; the wavelength division multiplexer (13) is connected to the pigtail of the third ferrule (10) in the high repetition rate laser resonant cavity; the pump end of the wavelength division multiplexer (13) is connected to the pump source (12), and the signal end is connected to the isolator (14); the isolator (14) is connected to the coupler (15); one end of the coupler (15) directly outputs the high repetition rate mode-locked pulse, and the other end is input to the photodetector (16); the photodetector (16) inputs the detected and converted signal to the phase-locked loop feedback circuit (17), and then promptly feeds back the error signal to the stacked piezoelectric actuator (11) in the high repetition rate laser resonant cavity. By adjusting the length of the high repetition rate laser resonant cavity, the repetition frequency is locked.

7. A high-repetition-rate laser pulse locking device according to claim 6, characterized in that, The phase-locked loop feedback circuit (17) is connected to the positive and negative terminals of the stacked piezoelectric actuator (11) in the high-repetition-rate laser resonant cavity, and generates an error signal based on the converted electrical signal detected by the photodetector (16), which is then fed back to the stacked piezoelectric actuator (11) in the high-repetition-rate laser resonant cavity.

8. A high-repetition-rate laser pulse locking device according to claim 7, characterized in that, The stacked piezoelectric actuator (11) in the high repetition rate laser resonant cavity generates an error signal response to the phase-locked loop feedback circuit (17) and extends and retracts in the direction parallel to the surface of the stacked piezoelectric actuator (11), thereby driving the gain fiber (7) in the high repetition rate laser resonant cavity to stretch, so that the repetition frequency of the high repetition rate laser resonant cavity is consistent with the reference frequency, and the high repetition rate laser pulse repetition frequency is locked.

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