Optical frequency self-stabilization high repetition frequency optical frequency comb generation device

Abstract

The invention discloses an optical frequency self-stabilization high repetition frequency optical frequency comb generation device, which comprises a passive mode-locking fiber laser and a Fabry-Perot ultra-stable cavity which are nested and coupled through a shared partial spatial light path. According to the invention, the problem that a traditional mode-locked laser is limited by the physical size of a resonant cavity and the repetition frequency is difficult to improve is broken through, and multiplication of the repetition frequencies of output optical frequency combs of different types of mode-locked lasers is realized.

Description

Technical Field

[0001] This invention relates to the field of fiber laser technology, specifically to a high repetition rate optical frequency comb generating device with self-stabilized optical frequency. Background Technology

[0002] Optical frequency combs based on ultrafast passive fiber mode-locked lasers have become the mainstream solution for commercial optical comb applications, playing an important role in precision spectral measurement, time-frequency transfer, and other fields. Compared with optical frequency combs based on electro-optic modulation or nonlinear Kerr microcavity schemes, passively mode-locked fiber lasers have lower noise and higher output power, showing significant advantages. However, the repetition frequency of such optical frequency combs is limited by the configuration of the laser resonator, usually within the gigahertz range. This characteristic severely restricts their application potential in more scenarios (see: Yang R, Zhao M, Jin X, et al. Attosecond timing jitter from high repetition rate femtosecond "solid-state fiber lasers". Optica, 2022, 9(8): 4.).

[0003] One study proposed nesting a Fabry-Perot cavity composed of fiber couplers within the main resonant cavity of a conventional mode-locked laser. By precisely controlling the lengths of the inner and outer cavities to ensure that their free spectral ranges are integer multiples, the repetition frequency of the optical frequency comb in the outer cavity can be multiplied. This scheme successfully achieved a low-noise, high-repetition-frequency "figure-9 cavity" mode-locked laser with a repetition frequency approaching the gigahertz range, providing a high-quality light source for applications such as astronomical spectral calibration and high-precision rapid ranging (see: Cao X, Zhou J, Cheng Z, et al. GHz Figure‐9 Er‐Doped Optical Frequency CombBased on Nested Fiber Ring Resonators. Laser & Photonics Reviews, 2023, 17(11)). However, due to the minimum physical length of the fiber fusion splicing process, further increasing the repetition frequency of this structure faces challenges. To achieve frequency stability of a passively mode-locked fiber laser, it is usually necessary to detect and lock its repetition frequency and carrier envelope offset frequency, or to perform optical beat frequency stabilization with an ultra-narrow linewidth single-frequency laser. The laser mentioned above operates freely in both its inner and outer cavities, and the comb frequency exhibits random drift. It is anticipated that a complex frequency locking system must be introduced before it can be used as a high-precision "optical frequency ruler" and become an optical frequency standard.

[0004] As the core device for achieving the highest level of laser frequency stability, the ultra-stable cavity is essentially a Fabry-Perot optical resonator with extremely high mechanical and thermal stability. It can be regarded as a high-precision "optical frequency ruler" used to calibrate the laser frequency. Currently, combining Pound-Drever-Hall (PDH) frequency stabilization technology with an ultra-stable cavity reference is the mainstream method for compressing the linewidth of single-frequency lasers and achieving frequency stability. If the stability of the ultra-stable cavity is transferred to the optical frequency comb, the traditional approach usually involves first locking the single-frequency laser to the ultra-stable cavity, and then locking the optical frequency comb to that single-frequency laser. However, this system has a complex structure and many components, which severely limits the flexibility and applicability of the optical frequency comb in complex applications. Summary of the Invention

[0005] The purpose of this invention is to provide a high repetition rate optical frequency comb generating device with self-stabilized optical frequency, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high repetition rate optical frequency comb generating device with self-stabilized optical frequency includes a passively mode-locked fiber laser and a Fabry-Perot ultra-stable cavity, which are nested and coupled together through a shared portion of the spatial optical path.

[0007] Furthermore, the free spectral range FSR1 of the passive mode-locked fiber laser and the free spectral range FSR2 of the Fabry-Perot ultrastable cavity satisfy the following relationship: FSR2 = n × FSR1, where n is a positive integer representing the frequency multiplication factor.

[0008] Furthermore, the pulse width of the ultrafast laser generated by the high repetition rate optical frequency comb generating device is in the range of hundreds of femtoseconds to hundreds of picoseconds, and the comb tooth spacing is in the range of hundreds of MHz to hundreds of GHz.

[0009] Furthermore, the Fabry-Perot superstable cavity includes a partial reflector, a total reflection mirror, and a mechanically packaged temperature control. The partial reflector is used to design the precision of the Fabry-Perot superstable cavity, the distance between the total reflection mirror and the partial reflector is used to control the free spectral range of the Fabry-Perot superstable cavity, and the mechanically packaged temperature control is used to isolate environmental interference and maintain temperature stability.

[0010] Furthermore, the cavity structure of the passively mode-locked fiber laser is a ring traveling wave cavity. The passively mode-locked fiber laser includes an output coupler, a pump wavelength division multiplexer, a pump laser, a gain fiber, a cavity length tuner, and a non-reciprocal phase shifter. The pump laser is connected to the reflecting end of the pump wavelength division multiplexer. The common end of the pump wavelength division multiplexer is connected to the gain fiber. The signal end of the pump wavelength division multiplexer is connected to the output coupler. The gain fiber, the cavity length tuner, the non-reciprocal phase shifter, and the output coupler are connected in sequence. The pump wavelength division multiplexer, the gain fiber, the cavity length tuner, the non-reciprocal phase shifter, and the output coupler form a ring circuit. The output coupler is coupled to the Fabry-Perot ultrastable cavity through a fiber collimator.

[0011] Furthermore, the pump wavelength division multiplexer is a 976 / 1550nm polarization-maintaining wavelength division multiplexer; the non-reciprocal phase shifter consists of two Faraday rotators and a quarter-wave plate, providing a linear phase bias of -π / 2; the pump laser source is a butterfly-packaged single-mode semiconductor pump laser tube; and the gain fiber is a 0.25m single-clad Er-doped fiber. 3+ The ion fiber has a mode field diameter of 6.5 μm, a cladding diameter of 125 μm, a pump absorption of 70 dB / m at 974 nm, and a dispersion parameter of -20 ps / (nm×km). The cavity length tuner is implemented by tuning the fiber bonded to the piezoelectric ceramic. The maximum tuning bandwidth of the cavity length tuner is 10 kHz, the operating voltage of the piezoelectric ceramic is 0-150 V, and the maximum stretch is 10 μm.

[0012] Furthermore, the output coupler is used to output pulsed laser light from a stable optical soliton inside the resonant cavity to an external cavity.

[0013] Furthermore, the cavity structure of the passively mode-locked fiber laser is a linear standing wave cavity. The passively mode-locked fiber laser includes a chirped fiber grating, a pump wavelength division multiplexer, a pump laser, a gain fiber, a cavity length tuner, and a single-walled carbon nanotube. The chirped fiber grating, cavity length tuner, pump wavelength division multiplexer, gain fiber, and single-walled carbon nanotube are connected in sequence. The pump laser is connected to the reflecting end of the pump wavelength division multiplexer. The common end of the pump wavelength division multiplexer is connected to the gain fiber. The signal end of the pump wavelength division multiplexer is connected to the cavity length tuner. The single-walled carbon nanotube is coupled to the Fabry-Perot ultrastable cavity through a passive fiber and a collimator.

[0014] Furthermore, the chirped fiber grating is a fiber grating etched onto a PM980 fiber using a phase mask, with a center wavelength of 1030 nm, a reflection bandwidth of 20 nm, a reflectivity of 12%, and a dispersion parameter of 0.2 ps / nm; the pump wavelength division multiplexer is a 976 / 1030 nm polarization-maintaining wavelength division multiplexer; the pump laser source is a butterfly-packaged single-mode semiconductor pump laser tube; and the gain fiber is a 0.25 m single-clad Yb-doped fiber.3+ The ion-optical fiber has a mode field diameter of 7.5 μm, a cladding diameter of 125 μm, a pump absorption of 250 dB / m at 975 nm, and a dispersion parameter of -4.5 ps / (nm×km). The cavity length tuner consists of a pair of fiber collimators. The single-walled carbon nanotube has an unsaturated absorption coefficient of 25% at 1030 nm, a modulation depth of 14.5%, and a saturable absorption energy of 0.2 MW / cm². 2 .

[0015] Furthermore, the pump wavelength division multiplexer is used to couple the pump laser from the pump laser into the resonant cavity, the gain fiber is used to provide amplified optical pulses by stimulated emission, the cavity length tuner is used to precisely fine-tune the resonant cavity length of the passive mode-locked fiber laser to ensure precise matching between the FSR and the Fabry-Perot ultrastable cavity, and the single-walled carbon nanotube, as a saturable absorber, is used for pulse narrowing and shaping to generate and maintain ultrashort pulse sequences.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1) It breaks through the predicament of traditional mode-locked lasers being limited by the physical size of the resonant cavity, making it difficult to increase the repetition frequency, and achieves a doubling of the repetition frequency of the output optical frequency comb of different types of mode-locked lasers.

[0017] 2) Compared to the complex frequency-locking stabilization link that requires dual-path optical frequency stabilization or repetition frequency loading wave envelope offset frequency of traditional precision optical frequency combs, the method provided by this invention can directly and conveniently achieve absolutely stable optical frequency laser output from an optical frequency matched ultra-stable cavity at low cost. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a high repetition rate optical frequency comb generating device with self-stabilized optical frequency according to Embodiment 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the Fabry-Perot ultrastable cavity structure in Embodiment 1 of the present invention.

[0020] Figure 3 This is a schematic diagram of a high repetition rate optical frequency comb generating device with self-stabilized optical frequency according to Embodiment 2 of the present invention.

[0021] Figure 4 This is a schematic diagram of the Fabry-Perot ultrastable cavity structure in Embodiment 2 of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: Please refer to Figure 1 A high-repetition-rate optical frequency comb generating device with self-stabilized optical frequency is disclosed, comprising a passively mode-locked fiber laser based on nonlinear amplifying ring mirror mode-locking and a Fabry-Perot ultrastable cavity 1. These components are nested and coupled through a shared spatial optical path. The ultrafast laser generated by the high-repetition-rate optical frequency comb generating device has a pulse width in the range of hundreds of femtoseconds to hundreds of picoseconds, and a comb spacing in the range of hundreds of MHz to hundreds of GHz. The spectral and temporal characteristics of the output laser depend on the configuration of the passively mode-locked laser, while the output optical frequency position and spacing are determined by the ultrastable cavity. The Fabry-Perot ultrastable cavity 1 includes a partial reflector 101, a total reflection mirror 102, and a mechanically encapsulated temperature control 103. The cavity structure of the passively mode-locked fiber laser is a ring traveling wave cavity, which includes an output coupler 2, a pump wavelength division multiplexer 3, a pump laser 4, a gain fiber 5, a cavity length tuner 6, and a non-reciprocal phase shifter 7. The pump laser 4 is connected to the reflection end of the pump wavelength division multiplexer 3, the common end of the pump wavelength division multiplexer 3 is connected to the gain fiber 5, and the signal end of the pump wavelength division multiplexer 3 is connected to the output coupler 2. The gain fiber 5, the cavity length tuner 6, the non-reciprocal phase shifter 7, and the output coupler 2 are connected in sequence. The pump wavelength division multiplexer 3, the gain fiber 5, the cavity length tuner 6, the non-reciprocal phase shifter 7, and the output coupler 2 form a ring loop. The output coupler 2 is coupled to the Fabry-Perot ultrastable cavity 1 through a fiber collimator. Pump wavelength division multiplexer 3 is used to couple the pump laser from pump laser 4 into the resonant cavity. Gain fiber 5 is used to provide amplified optical pulses through stimulated emission. Cavity length tuner 6 is used to precisely fine-tune the resonant cavity length of the passively mode-locked fiber laser to ensure accurate matching between the FSR and the Fabry-Perot ultrastable cavity 1. Output coupler 2 provides spatial light output or output via optical fiber. Output coupler 2 is used to output pulsed laser light from the stable optical soliton inside the resonant cavity to the outside of the cavity.

[0024] The Fabry-Perot ultrastable cavity 1 is a cylindrical ultrastable cavity made of ultra-low expansion glass, with a length of 100 mm and an FSR of 1.5 GHz. By matching the length of the fiber inside the cavity of the passively mode-locked laser and the cavity length tuner 6, the free spectral range (FSR) of the ultrastable cavity is made to be an integer multiple of its FSR. That is, the free spectral range FSR1 of the passively mode-locked fiber laser and the free spectral range FSR2 of the Fabry-Perot ultrastable cavity satisfy the relationship: FSR2 = n × FSR1, where n is a positive integer representing the frequency multiplication factor.

[0025] As shown in Figure 2, the Fabry-Perot ultrastable cavity 1 includes a partial reflector 101, a total reflector 102, and a mechanically packaged temperature controller 103. The partial reflector 101 and the total reflector 102 are dielectric films vapor-deposited onto the parallel ends of a cylinder made of ultra-low expansion glass. They are held in place by a mechanical package made of 6061 aluminum alloy. The mechanically packaged temperature controller 103 includes a polyimide heating element and aluminum foil insulation attached to the mechanical package. The partial reflector 101 is used to design the precision of the ultrastable cavity. The distance between the total reflector 102 and the partial reflector 101 is used to control the free spectral range of the ultrastable cavity. The mechanically packaged temperature controller 103 is used to isolate environmental interference and maintain temperature stability, thereby ensuring the long-term stable operation of the ultrastable cavity.

[0026] The passively mode-locked fiber laser with nonlinear amplifying ring mirror mode-locking consists of a ring arm and a linear arm. The ring arm includes a 976 / 1550nm polarization-maintaining wavelength division multiplexer (pump wavelength division multiplexer 3) that couples the output laser from pump laser 4 into Er-doped fiber laser as the gain medium. 3+ Ion fiber (gain fiber 5). A 0.42m polarization-maintaining dispersion-compensating fiber is used to balance the cavity dispersion, making the net dispersion within the cavity close to zero. To induce a nonlinear phase shift difference between clockwise and counterclockwise propagation to optimize self-starting, gain fiber 5 is positioned close to the high-ratio end of the ring arm of output coupler 2. The non-reciprocal phase shifter 7 consists of two Faraday rotators and a quarter-wave plate, providing a linear phase bias of -π / 2.

[0027] Pump laser 4 is a single-mode 976nm laser diode, which is a 14-pin butterfly-packaged single-mode pump laser diode with model number LC96Z600-76.

[0028] Gain fiber 5 is a 0.25m single-clad Er-doped fiber. 3+ The ion fiber has a mode field diameter of 6.5 μm, a cladding diameter of 125 μm, a pump absorption of 70 dB / m at 974 nm, and a dispersion parameter of -20 ps / (nm×km).

[0029] The cavity length tuner 6 is implemented by tuning an optical fiber bonded to a piezoelectric ceramic (PZT), with a maximum tuning bandwidth of 10 kHz, a PZT operating voltage of 0-150 V, and a maximum stretch of 10 μm. The cavity length tuner 6 is used to achieve precise matching within a free spectral range, specifically by tuning the stretched optical fiber or tuning a spatially coupled optical delay line.

[0030] The Fabrypero ultra-stable cavity 1 is encapsulated with temperature control and insulation, and achieves constant temperature control of 25°C through an external temperature control link.

[0031] The cavity of a passively mode-locked laser is entirely composed of polarization-maintaining fibers and fiber optic assemblies, which is used to improve the long-term stability of the output pulse.

[0032] In this embodiment, the passively mode-locked laser has a repetition rate of 100MHz, a center wavelength of 1550nm, and a spectral 3dB bandwidth of 80nm when independently mode-locked. Through nested coupling with an ultrastable cavity, a 1.5GHz mode-locked pulse output matching the repetition rate of the ultrastable cavity is achieved.

[0033] Example 2: Please refer to Figure 3 A high-repetition-rate optical frequency comb generating device with self-stabilizing optical frequency is proposed, consisting of a passively mode-locked fiber laser based on a material-like saturable absorber, carbon nanotube (CNT), and a Fabry-Perot ultrastable cavity 1. These components are nested and coupled through a shared spatial optical path. The ultrafast laser generated by the high-repetition-rate optical frequency comb generating device has a pulse width in the range of hundreds of femtoseconds to hundreds of picoseconds, and a comb tooth spacing in the range of hundreds of MHz to hundreds of GHz. The spectral and temporal characteristics of the output laser depend on the configuration of the passively mode-locked laser, while the output optical frequency position and spacing are determined by the ultrastable cavity. The cavity structure of the passively mode-locked fiber laser is a linear standing wave cavity, comprising a chirped fiber grating 8, a cavity length tuner 6, a pump wavelength division multiplexer 3, a pump laser 4, a gain fiber 5, and a single-walled carbon nanotube 9, which are connected via a polarization-maintaining PM980 fiber. A chirped fiber grating 8, a cavity length tuner 6, a pump wavelength division multiplexer 3, a gain fiber 5, and a single-walled carbon nanotube 9 are connected in sequence. The pump laser 4 is connected to the reflecting end of the pump wavelength division multiplexer 3. The common end of the pump wavelength division multiplexer 3 is connected to the gain fiber 5. The signal end of the pump wavelength division multiplexer 3 is connected to the cavity length tuner 6. The single-walled carbon nanotube 9 is connected to the Fabry-Perot ultrastable cavity 1. The pump wavelength division multiplexer 3 is used to couple the pump laser from the pump laser 4 into the resonant cavity. The gain fiber 5 is used to provide amplified optical pulses through stimulated emission. The cavity length tuner 6 is used to precisely fine-tune the resonant cavity length of the passively mode-locked fiber laser to ensure precise matching between the FSR and the Fabry-Perot ultrastable cavity 1. The single-walled carbon nanotube 9, as a saturable absorber, is used for pulse narrowing and shaping to generate and maintain ultrashort pulse sequences.

[0034] The Fabry-Perot ultrastable cavity 1 is a pyramidal ultrastable cavity made of ultra-low expansion glass, with a length of 25 mm and an FSR of 6 GHz. By matching the length of the fiber inside the cavity of the passively mode-locked laser and the cavity length tuner 6, the free spectral range (FSR) of the ultrastable cavity is made to be an integer multiple of its FSR. That is, the free spectral range FSR1 of the passively mode-locked fiber laser and the free spectral range FSR2 of the Fabry-Perot ultrastable cavity satisfy the relationship: FSR2 = n × FSR1, where n is a positive integer representing the frequency multiplication factor.

[0035] like Figure 4As shown, the Fabry-Perot ultrastable cavity 1 includes a partial reflector 101, a total reflector 102, and a mechanically packaged temperature controller 103. The partial reflector 101 and the total reflector 102 are dielectric films vapor-deposited onto the parallel ends of a pyramid made of ultra-low expansion glass, and are held in place by a mechanical package made of 6061 aluminum alloy. The mechanically packaged temperature controller 103 includes a polyimide heating element and aluminum foil insulation attached to the mechanical package. The partial reflector 101 is used to design the precision of the ultrastable cavity, the distance between the total reflector 102 and the partial reflector 101 is used to control the free spectral range of the ultrastable cavity, and the mechanically packaged temperature controller 103 is used to isolate environmental interference and maintain temperature stability, thereby ensuring the long-term stable operation of the ultrastable cavity.

[0036] The chirped fiber grating 8 is a fiber grating etched onto a PM980 fiber using a phase mask. It has a center wavelength of 1030nm, a reflection bandwidth of 20nm, a reflectivity of 12%, and a dispersion parameter of 0.2ps / nm.

[0037] The 976 / 1030nm polarization-maintaining wavelength division multiplexer (pump wavelength division multiplexer 3) couples the output laser from pump laser 4 into the Yb-doped medium used as the gain medium. 3+ Ion fiber (gain fiber 5).

[0038] Pump laser 4 is a single-mode 976nm laser diode, which is a 14-pin butterfly-packaged single-mode pump laser diode with model number LC96Z600-76.

[0039] Gain fiber 5 is a 0.25m single-clad Yb-doped fiber. 3+ The ion fiber has a mode field diameter of 7.5 μm, a cladding diameter of 125 μm, a pump absorption of 250 dB / m at 975 nm, and a dispersion parameter of -4.5 ps / (nm×km).

[0040] The cavity length tuner 6 consists of a pair of fiber collimators mounted on a stepping stage. By applying voltage to the stepping stage through a driver, stepping tuning with a precision of 10nm can be achieved. The cavity length tuner 6 is used to achieve precise matching within a free spectral range, specifically by tuning a stretched fiber or tuning a spatially coupled optical delay line.

[0041] Single-walled carbon nanotube 9 exhibits an unsaturated absorption coefficient of 25% and a modulation depth of 14.5% at a wavelength of 1030 nm, with a saturable absorption energy of 0.2 MW / cm². 2 The single-walled carbon nanotube 9 is held in the fiber optic flange by two FC / UPC jumpers, which are coupled into the fiber optic resonant cavity.

[0042] In this embodiment, the passively mode-locked laser has a repetition rate of 40 MHz, a center wavelength of 1030 nm, and a spectral 3dB bandwidth of 15 nm when independently mode-locked. Through nested coupling with an ultrastable cavity, a 6 GHz mode-locked pulse output matching the repetition rate of the ultrastable cavity is achieved.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high repetition rate optical frequency comb generating device with self-stabilized optical frequency, characterized in that, It includes a passively mode-locked fiber laser and a Fabry-Perot ultrastable cavity (1), which are nested and coupled together by sharing a portion of the spatial optical path.

2. The optical frequency comb generating device with self-stabilized optical frequency according to claim 1, characterized in that, The free spectral range FSR1 of the passive mode-locked fiber laser and the free spectral range FSR2 of the Fabry-Perot ultrastable cavity satisfy the following relationship: FSR2 = n × FSR1, where n is a positive integer representing the frequency multiplication factor.

3. The optical frequency comb generating device with self-stabilized optical frequency according to claim 1, characterized in that, The ultrafast laser generated by the high repetition rate optical frequency comb generating device has a pulse width in the range of hundreds of femtoseconds to hundreds of picoseconds and a comb tooth spacing in the range of hundreds of MHz to hundreds of GHz.

4. The optical frequency self-stabilizing high repetition rate optical frequency comb generating device according to claim 1, characterized in that, The Fabry-Perot superstable cavity (1) includes a partial reflector (101), a total reflection mirror (102), and a mechanically packaged temperature controller (103). The partial reflector (101) is used to design the precision of the Fabry-Perot superstable cavity (1). The distance between the total reflection mirror (102) and the partial reflector (101) is used to control the free spectral range of the Fabry-Perot superstable cavity (1). The mechanically packaged temperature controller (103) is used to isolate environmental interference and maintain temperature stability.

5. The optical frequency comb generating device with self-stabilized optical frequency according to claim 1, characterized in that, The cavity structure of the passive mode-locked fiber laser is a ring traveling wave cavity. The passive mode-locked fiber laser includes an output coupler (2), a pump wavelength division multiplexer (3), a pump laser (4), a gain fiber (5), a cavity length tuner (6), and a non-reciprocal phase shifter (7). The pump laser (4) is connected to the reflection end of the pump wavelength division multiplexer (3). The common end of the pump wavelength division multiplexer (3) is connected to the gain fiber (5). The signal end of the pump wavelength division multiplexer (3) is connected to the output coupler (2). The gain fiber (5), the cavity length tuner (6), the non-reciprocal phase shifter (7), and the output coupler (2) are connected in sequence. The pump wavelength division multiplexer (3), the gain fiber (5), the cavity length tuner (6), the non-reciprocal phase shifter (7), and the output coupler (2) form a ring circuit. The output coupler (2) is coupled to the Fabry-Perot ultrastable cavity (1) through a fiber collimator.

6. The optical frequency self-stabilizing high repetition rate optical frequency comb generating device according to claim 5, characterized in that, The pump wavelength division multiplexer (3) is a 976 / 1550nm polarization-maintaining wavelength division multiplexer; the non-reciprocal phase shifter (7) consists of two Faraday rotators and a quarter-wave plate, providing a linear phase bias of -π / 2; the pump laser (4) is a butterfly-packaged single-mode semiconductor pump laser tube. The gain fiber (5) is a 0.25m single-clad Er-doped fiber. 3+ The ion fiber has a mode field diameter of 6.5 μm, a cladding diameter of 125 μm, a pump absorption of 70 dB / m at 974 nm, and a dispersion parameter of -20 ps / (nm×km). The cavity length tuner (6) is implemented by tuning the fiber bonded to the piezoelectric ceramic. The maximum tuning bandwidth of the cavity length tuner (6) is 10 kHz, the working voltage of the piezoelectric ceramic is 0-150 V, and the maximum stretch is 10 μm.

7. The optical frequency comb generating device with self-stabilized optical frequency according to claim 5, characterized in that, The output coupler (2) is used to output pulsed laser light from the stable optical soliton inside the resonant cavity to the outside of the cavity.

8. The optical frequency self-stabilizing high repetition rate optical frequency comb generating device according to claim 1, characterized in that, The cavity structure of the passive mode-locked fiber laser is a linear standing wave cavity. The passive mode-locked fiber laser includes a chirped fiber grating (8), a pump wavelength division multiplexer (3), a pump laser (4), a gain fiber (5), a cavity length tuner (6), and a single-walled carbon nanotube (9). The chirped fiber grating (8), the cavity length tuner (6), the pump wavelength division multiplexer (3), the gain fiber (5), and the single-walled carbon nanotube (9) are connected in sequence. The pump laser (4) is connected to the reflecting end of the pump wavelength division multiplexer (3). The common end of the pump wavelength division multiplexer (3) is connected to the gain fiber (5). The signal end of the pump wavelength division multiplexer (3) is connected to the cavity length tuner (6). The single-walled carbon nanotube (9) is coupled to the Fabry-Perot ultrastable cavity (1) through a passive fiber and a collimator.

9. The optical frequency self-stabilizing high repetition rate optical frequency comb generating device according to claim 8, characterized in that, The chirped fiber grating (8) is a fiber grating etched onto a PM980 fiber using a phase mask, with a center wavelength of 1030 nm, a reflection bandwidth of 20 nm, a reflectivity of 12%, and a dispersion parameter of 0.2 ps / nm; the pump wavelength division multiplexer (3) is a 976 / 1030 nm polarization-maintaining wavelength division multiplexer; the pump laser (4) is a butterfly-packaged single-mode semiconductor pump laser tube; and the gain fiber (5) is a 0.25 m single-clad Yb-doped fiber. 3+ The ion-optical fiber has a mode field diameter of 7.5 μm, a cladding diameter of 125 μm, a pump absorption of 250 dB / m at 975 nm, and a dispersion parameter of -4.5 ps / (nm×km). The cavity length tuner (6) consists of a pair of fiber collimators. The single-walled carbon nanotube (9) has an unsaturated absorption coefficient of 25% at a wavelength of 1030 nm, a modulation depth of 14.5%, and a saturable absorption energy of 0.2 MW / cm. 2 .

10. A high repetition rate optical frequency comb generating device with self-stabilized optical frequency according to any one of claims 5-9, characterized in that, The pump wavelength division multiplexer (3) is used to couple the pump laser of the pump laser (4) into the resonant cavity. The gain fiber (5) is used to provide amplified optical pulses by stimulated emission. The cavity length tuner (6) is used to precisely fine-tune the resonant cavity length of the passive mode-locked fiber laser so that the FSR is precisely matched with the Fabry-Perot ultrastable cavity (1). The single-walled carbon nanotube (9) is used as a saturable absorber for pulse narrowing and shaping to generate and maintain an ultrashort pulse sequence.

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