A laser cavity soliton microcomb system and a tuning method thereof

Abstract

This invention discloses a laser cavity soliton microcomb system and its tuning method, relating to the field of integrated photonic chips. A reconfigurable spectral filtering module combining a diffraction grating and an fiber collimator replaces the traditional fixed-parameter filter. Tuning of the center wavelength is achieved by adjusting the angle of the diffraction grating, and tuning of the spectral bandwidth is achieved by adjusting the relative position between the fiber collimator and the diffraction grating. Simultaneously, the synergistic effect of the diffraction grating and the fiber collimator enables highly efficient filtering, greatly improving the system's adaptability to different application scenarios. Multi-wavelength continuously tunable filtering is achieved through the diffraction grating and fiber collimator, eliminating the need to replace multiple fixed filters and significantly reducing the number of components and debugging and maintenance costs. In the laser cavity soliton microcomb system, the reconfigurable spectral filtering module has a compact structure and flexible adjustment, achieving dynamic tuning of both wavelength and bandwidth in two dimensions without introducing significant insertion loss, thus realizing high-performance spectral management.

Description

Technical Field

[0001] This invention relates to the field of integrated photonic chips, and in particular to a laser cavity soliton microcomb system and its tuning method. Background Technology

[0002] High repetition rate lasers play an irreplaceable core role in cutting-edge technologies such as high-speed optical communication, optical computing, and microwave photonics. However, achieving a balance between high stability and high power output still faces technical bottlenecks. Traditional fiber-locked lasers require ultrashort cavity designs to increase repetition rate, resulting in limited gain medium length and significantly reduced output energy and average power, making it difficult to stably achieve high repetition rates above tens of GHz. Harmonic mode-locking schemes can improve repetition rate to some extent, but these schemes generally suffer from insufficient long-term stability and limited repetition rate control precision. Kerr frequency combs based on high-quality factor microcavities provide an important technical path to achieve high repetition rates. Their repetition rate is determined by the free spectral range of the microcavity itself, effectively breaking through the cavity length limitations of traditional lasers and possessing significant advantages such as compact structure and ease of integration.

[0003] Laser cavity soliton microcomb systems typically include core functional components such as gain media, microresonant cavities, fiber optic resonant cavities, and spectral filters. Among these, the spectral filter plays a crucial role; a properly wide spectral filter can effectively suppress spontaneous emission noise, assist in pulse shaping, and lock the operating wavelength. However, most existing systems use spectral filters with fixed center wavelengths and bandwidths, lacking dynamic tuning capabilities. This severely restricts the system's adaptability and flexibility in different application scenarios. For example, in applications such as spectral analysis, it is impossible to extend the detection range through wavelength scanning; and in optical communication systems, it is difficult to dynamically adjust the operating wavelength according to channel allocation requirements.

[0004] Therefore, how to solve the problem of insufficient system tuning capability caused by fixed parameter filters in the existing technology is a technical problem that urgently needs to be solved by those in the field. Summary of the Invention

[0005] The purpose of this invention is to provide a laser cavity soliton microcomb system and its tuning method to solve the technical problem of insufficient system tuning capability caused by fixed parameter filters in the prior art.

[0006] To address the aforementioned technical problems, this invention provides a laser cavity soliton microcomb system, comprising:

[0007] A fiber laser resonator is used to provide optical amplification and establish laser oscillation.

[0008] The micro-resonant cavity nested within the fiber laser resonant cavity is used to provide periodic filtering and achieve pulse shaping through Kerr nonlinearity.

[0009] A reconfigurable spectral filtering module is located between the output end of the microresonator and the input end of the fiber laser resonator. It is used to perform tunable filtering on the beam emitted from the microresonator and return the tunable filtered beam to the fiber laser resonator.

[0010] The reconfigurable spectral filtering module includes a diffraction grating and a first fiber collimator placed sequentially along the beam transmission direction; wherein, the center wavelength is tuned by adjusting the angle of the diffraction grating, and the spectral bandwidth is tuned by adjusting the relative position between the first fiber collimator and the diffraction grating.

[0011] The laser cavity soliton microcomb system provided by this invention replaces the traditional fixed-parameter filter with a structure combining a diffraction grating and a first fiber collimator. The center wavelength is tuned by adjusting the angle of the diffraction grating, and the spectral bandwidth is tuned by adjusting the relative position between the first fiber collimator and the diffraction grating. Simultaneously, the synergistic effect of the diffraction grating and the first fiber collimator enables efficient filtering. Compared to existing laser cavity soliton microcomb systems using fixed-parameter filters, the laser cavity soliton microcomb system provided by this invention achieves adjustable center wavelength and bandwidth, greatly improving the system's adaptability to different application scenarios. Multi-wavelength continuously adjustable filtering is achieved through the diffraction grating and fiber collimator, eliminating the need to replace multiple fixed filters and significantly reducing the number of components and debugging and maintenance costs. In the laser cavity soliton microcomb system, the reconfigurable spectral filtering module has a compact structure and flexible adjustment, enabling dynamic tuning of both wavelength and bandwidth in two dimensions without introducing significant insertion loss, achieving high-performance spectral management.

[0012] For example, the laser cavity soliton microcomb system also includes a displacement stage; the displacement stage is connected to a first fiber collimator and is used to adjust the relative position between the first fiber collimator and the diffraction grating. The spectral width is adjusted by controlling the distance between the displacement stage and the diffraction grating; and adjusting the distance between the first fiber collimator and the diffraction grating via the displacement stage enables high-precision and stable position adjustment, avoiding problems such as jitter and deviation caused by manual adjustment, effectively improving the stability and controllability of the adjustment process.

[0013] For example, the laser cavity soliton microcomb system further includes a rotating mechanism; the rotating mechanism is connected to a diffraction grating for adjusting the angle of the diffraction grating; or, it further includes a temperature control component, which contacts the diffraction grating for adjusting the angle of the diffraction grating. Thus, the angle of the diffraction grating can be adjusted in different ways, improving the flexibility of diffraction grating angle adjustment, and the center frequency can be continuously tunable by adjusting the angle of the diffraction grating through the rotating mechanism.

[0014] For example, the laser cavity soliton microcomb system further includes a first half-wave plate; the first half-wave plate is located between the diffraction grating and the first fiber collimator, and is used to regulate the polarization state of the light incident on the diffraction grating and transmit the regulated beam to the first fiber collimator. The first half-wave plate is disposed between the diffraction grating and the first fiber collimator to finely regulate the polarization state of the light emitted from the diffraction grating, so that the polarization characteristics of the light match the receiving conditions of the first fiber collimator, thereby improving the system coupling efficiency and operational stability.

[0015] For example, the laser cavity soliton microcomb system also includes a cavity length matching and feedback control unit; the cavity length matching and feedback control unit is located between the output end of the reconfigurable spectral filtering module and the input end of the fiber laser resonator, and is used to adjust the total length of the fiber laser resonator. By adjusting the total length of the fiber laser resonator through the cavity length matching and feedback control unit, it is possible to precisely match the target longitudinal mode frequency of the microresonator and control the detuning of the optical field within the microcavity resonant line shape, so as to achieve the self-starting and stable operation of the soliton.

[0016] For example, the cavity length matching and feedback control unit includes an optical delay line; the input end of the optical delay line is connected to the output end of the first fiber collimator, and the output end of the optical delay line is connected to the input end of the fiber laser resonator, used to adjust the total length of the fiber laser resonator. Through the optical delay line, the total length of the fiber laser cavity can be precisely adjusted to accurately match the target longitudinal mode frequency of the micro-resonator, and the detuning of the optical field within the micro-cavity resonant line shape can be controlled to achieve soliton self-starting and stable operation.

[0017] For example, the diffraction grating can be a transmission-type blazed grating or a reflection-type blazed grating. By concentrating most of the light energy onto a single order of diffraction spectrum using a blazed grating, the diffraction efficiency of the target order can be significantly improved, far exceeding that of ordinary gratings. When the first-order diffraction efficiency at the blaze wavelength is maximized, the first-order diffracted light spatially disperses the frequency of the incident light. Combined with an optical fiber collimator with a fixed-size receiving end face, a spectral filtering effect can be achieved. Furthermore, when the sampled diffraction grating is a reflection-type blazed grating, the size of the reconfigurable spectral filtering module can be reduced through optical path folding, thereby reducing the size of the laser cavity soliton microcomb system.

[0018] For example, the fiber laser resonant cavity includes a fiber amplifier, a fiber isolator, a second fiber collimator, a second half-wave plate, a first collimating element, a second collimating element, a third half-wave plate, and a polarization beam splitter, arranged sequentially along the beam propagation direction. A micro-resonant cavity is disposed between the first and second collimating elements. The first output end of the polarization beam splitter is connected to the input end of a reconfigurable spectral filtering module. The second output end of the polarization beam splitter is used to output a soliton microcomb. In this fiber laser resonant cavity, the output end of the fiber amplifier is connected to the input end of the fiber isolator, ensuring unidirectional operation of the optical field within the laser cavity. The output end of the fiber isolator is connected to the diverging spatial light input second fiber collimator, which collimates the beam propagating in the fiber and converts it into parallel spatial light. The collimated beam passes sequentially through the second half-wave plate, which is used to adjust and select the polarization state and optical power of the incoming beam. Subsequently, the beam is focused by the first collimating element and coupled into the micro-resonant cavity, which serves as the core nonlinear element. The output light from the micro-resonator is re-collimated by the second collimating element and then passes through the third half-wave plate and polarization beam splitter in sequence to optimize the optical path state before entering the reconfigurable spectral filtering module.

[0019] For example, the microresonator is a Fabry-Perot microcavity, or an on-chip microcavity with a quality factor greater than a preset value. Using a Fabry-Perot microcavity or an on-chip microcavity with a quality factor higher than the preset value as the microresonator achieves both narrow linewidth and high frequency selection accuracy resonant filtering effects. Furthermore, leveraging the small size, high integration, and good stability of on-chip microcavities improves system integration and operational reliability, resulting in a simpler overall structure and more stable performance.

[0020] On the other hand, the present invention also provides a tuning method for a laser cavity soliton microcomb system, applied to the aforementioned laser cavity soliton microcomb system, the method comprising:

[0021] Adjusting the angle of the diffraction grating controls the center wavelength of the laser cavity soliton microcomb system;

[0022] The relative position between the first fiber collimator and the diffraction grating is adjusted to control the spectral bandwidth of the laser cavity soliton microcomb system.

[0023] The tuning method for the laser cavity soliton microcomb system provided in this embodiment, when applied to the aforementioned laser cavity soliton microcomb system, has the same or corresponding technical features as the aforementioned laser cavity soliton microcomb system, and achieves the same effect. Attached Figure Description

[0024] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of a laser cavity soliton microcomb system provided in an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of a specific laser cavity soliton microcomb system provided in an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of a reconfigurable spectral filtering module provided in an embodiment of the present invention;

[0028] Figure 4 A schematic diagram illustrating the positional relationship between a first fiber collimator and a displacement stage, provided for an embodiment of the present invention;

[0029] Figure 5 A flowchart illustrating a tuning method for a laser cavity soliton microcomb system provided in an embodiment of the present invention.

[0030] The attached figures are labeled as follows:

[0031] 10-Fiber laser resonant cavity; 101-Micro resonant cavity; 102-Fiber amplifier; 103-Fiber isolator; 104-Second fiber collimator; 105-Second half-wave plate; 106-First collimating element; 107-Second collimating element; 108-Third half-wave plate; 109-Polarization beam splitter;

[0032] 20-Reconfigurable spectral filtering module; 201-Diffraction grating; 202-First fiber collimator; 203-Displacement stage; 204-First half-wave plate;

[0033] 30 - Cavity length matching and feedback control unit. Detailed Implementation

[0034] 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 of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0035] The core of this invention is to provide a laser cavity soliton microcomb system and its tuning method to solve the technical problem of insufficient system tuning capability caused by fixed parameter filters in the prior art.

[0036] In this laser cavity soliton microcomb system, a reconfigurable spectral filter module combining a diffraction grating and an fiber collimator is integrated and applied to the system. This module not only achieves efficient spectral filtering but also enables dynamic tunability of the system's center wavelength and spectral width through precise adjustment of the diffraction grating angle and fiber collimator position. This design fundamentally solves the technical limitations of traditional fixed filters in laser cavity soliton microcomb systems, providing a more flexible and precise means of spectral management without increasing system complexity. By introducing this reconfigurable spectral filter module, the system can quickly adjust its operating parameters according to different application requirements, significantly improving overall performance and adaptability. This solution provides a complete technical path for high-repetition-rate, high-efficiency optical frequency comb systems, offering a compact, precisely controlled, and highly adaptable reconfigurable spectral filter module. It lays a solid technical foundation for their widespread application in precision optical measurement, high-speed optical communication, multi-band spectral analysis, and optical communication, demonstrating significant industrial application value and market prospects.

[0037] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Figure 1 This is a schematic diagram of a laser cavity soliton microcomb system provided in an embodiment of the present invention, as shown below. Figure 1 As shown, it includes:

[0038] The fiber laser resonator 10 is used to provide optical amplification and establish laser oscillation.

[0039] The micro-resonant cavity 101, nested within the fiber laser resonant cavity 10, is used to provide periodic filtering and achieve pulse shaping through the Kerr nonlinear effect;

[0040] The reconfigurable spectral filtering module 20 is located between the output end of the micro resonant cavity 101 and the input end of the fiber laser resonant cavity 10. It is used to perform tunable filtering on the beam emitted from the micro resonant cavity 101 and return the tunable filtered beam to the fiber laser resonant cavity 10.

[0041] The reconfigurable spectral filtering module 20 includes a diffraction grating 201 and a first fiber collimator 202 placed sequentially along the beam transmission direction; wherein, the center wavelength is tuned by adjusting the angle of the diffraction grating 201, and the spectral bandwidth is tuned by adjusting the relative position between the first fiber collimator 202 and the diffraction grating 201.

[0042] The fiber laser resonator 10, serving as the main framework of the system, includes a gain medium, an optical isolator, a wavelength division multiplexer, etc., used to provide optical amplification and establish laser oscillation. In one possible implementation, the fiber laser resonator 10 includes, sequentially arranged along the beam propagation direction, an fiber amplifier 102, a fiber isolator 103, a second fiber collimator 104, a second half-wave plate 105, a first collimating element 106, a second collimating element 107, a third half-wave plate 108, and a polarization beam splitter 109, such as... Figure 2 As shown, Figure 2 This is a schematic diagram of a specific laser cavity soliton microcomb system provided in an embodiment of the present invention.

[0043] A micro-resonant cavity 101 is provided between the first collimating element 106 and the second collimating element 107;

[0044] The first output terminal of the polarization beam splitter 109 is connected to the input terminal of the reconfigurable spectral filter module 20;

[0045] The second output terminal of the polarization beam splitter 109 is used to output soliton microcomb.

[0046] In laser cavity soliton microcomb systems, in addition to the communication band, the system can be extended to the generation and application of optical frequency combs in other spectral regions such as near-infrared and mid-infrared by selecting fiber gain media, microcavities and grating elements of the corresponding band.

[0047] Both the first collimating element 106 and the second collimating element 107 can be lenses. In this fiber laser resonator 10, the output end of the fiber amplifier 102 is connected to the input end of the fiber isolator 103, ensuring unidirectional operation of the optical field within the laser cavity; the output end of the fiber isolator 103 is connected to the diverging spatial light input second fiber collimator 104, which collimates the beam transmitted in the fiber and converts it into parallel spatial light. The collimated beam passes sequentially through the second half-wave plate 105, which is used to adjust and select the polarization state and optical power of the incoming beam. Subsequently, the beam is focused by the first collimating element 106 and coupled into the microresonator 101, which serves as the core nonlinear element. The output light from the microresonator 101 is re-collimated by the second collimating element 107 and then sequentially passes through the third half-wave plate 108 and the polarization beam splitter 109 to optimize the optical path state before entering the reconfigurable spectral filtering module 20.

[0048] A high-quality factor micro-resonator 101 is nested within the aforementioned fiber laser resonator 10. The micro-resonator 101, serving as the core for nonlinearity and filtering, is nested within the fiber laser resonator 10 to provide fine periodic filtering and pulse shaping via the Kerr nonlinear effect.

[0049] The microresonator 101 used is not limited. In one possible implementation, the microresonator 101 is a Fabry-Perot microcavity, or the microresonator 101 is an on-chip microcavity with a quality factor greater than a preset value, such as a preset value of or Highly nonlinear optical fibers can be used as microcavities, leveraging their low optical loss and high nonlinear coefficient characteristics to realize high-quality factor Fabry-Perot (FP) microcavities. In high-quality microcavity structures, microring resonators can also be used instead of FP cavities. On-chip microcavities can be based on on-chip high-quality factor microcavity structures such as silicon dioxide or silicon nitride.

[0050] In this embodiment, a Fabry-Perot microcavity or an on-chip microcavity with a quality factor higher than a preset value is used as the micro-resonant cavity 101. This can achieve a resonant filtering effect with narrow linewidth and high frequency selection accuracy. It can also improve the system integration level and operational reliability by taking advantage of the small size, high integration and good stability of the on-chip microcavity. The overall structure is simpler and the performance is more stable.

[0051] To achieve dynamic tunability of the system's center wavelength and spectral width, a reconfigurable spectral filtering module 20 is employed in this invention. The reconfigurable spectral filtering module 20 is located between the output of the microresonator 101 and the input of the fiber laser resonator 10, and is used to perform tunable filtering on the beam emitted from the microresonator 101 and return the tunably filtered beam to the fiber laser resonator 10.

[0052] Figure 3 This is a schematic diagram of a reconfigurable spectral filtering module provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the reconfigurable spectral filtering module 20 includes a diffraction grating 201 and a first fiber collimator 202 placed sequentially along the beam transmission direction. The diffraction grating 201 is responsible for spatially separating the incident light according to wavelength. Furthermore, the center wavelength is tuned by adjusting the angle of the diffraction grating 201, and the spectral bandwidth is tuned by adjusting the relative position between the first fiber collimator 202 and the diffraction grating 201. In one possible implementation, the diffraction grating 201 is a transmission-type blazed grating or a reflection-type blazed grating. Figure 3 The diffraction grating 201 used in this system is a reflective blazed grating. By concentrating most of the light energy onto a single order of diffraction spectrum using a blazed grating, the diffraction efficiency of the target order can be significantly improved, far exceeding that of ordinary gratings. When the first-order diffraction efficiency at the blaze wavelength is maximized, the first-order diffracted light disperses the frequency of the incident light in space. Combined with an optical fiber collimator with a fixed-size receiving end face, a spectral filtering effect can be achieved. Furthermore, when the sampling diffraction grating 201 is a reflective blazed grating, the volume of the reconfigurable spectral filtering module 20 can be reduced through optical path folding, thereby reducing the volume of the laser cavity soliton microcomb system.

[0053] To adjust the relative position (specifically, the distance) between the first fiber collimator 202 and the diffraction grating 201 to achieve dynamic bandwidth tuning, their relative position can be adjusted manually. However, direct manual adjustment is affected by human factors, resulting in fluctuations and poor accuracy during the adjustment process. Therefore, in some possible implementations, the laser cavity soliton microcomb system also includes a displacement stage 203. Figure 4 This is a schematic diagram illustrating the positional relationship between a first fiber collimator and a displacement stage, provided in an embodiment of the present invention. The displacement stage 203 is connected to the first fiber collimator 202 and is used to adjust the relative position between the first fiber collimator 202 and the diffraction grating 201 while keeping the position of the diffraction grating 201 fixed.

[0054] In this laser cavity soliton microcomb system, the distance between the fiber collimator and the diffraction grating 201 can be achieved by mechanical translation (i.e., displacement stage 203). While keeping the position of the diffraction grating 201 fixed, the active control of the received spectral width can be achieved, thereby realizing different types of soliton output by adjusting the width of the spectral filter. Furthermore, by adjusting the distance between the first fiber collimator 202 and the diffraction grating 201 through the displacement stage 203, high-precision and stable position adjustment can be achieved, avoiding problems such as jitter and deviation caused by manual adjustment, and effectively improving the stability and controllability of the adjustment process.

[0055] In the above embodiments, the distance between the first fiber collimator 202 and the displacement stage 203 is adjusted by the displacement stage 203, achieving bandwidth tunability. To achieve wavelength tunability, the angle of the diffraction grating 201 needs to be adjusted. In practice, the rotation angle of the diffraction grating 201 can be adjusted manually or electrically. In one possible implementation, the laser cavity soliton microcomb system further includes a rotation mechanism. The rotation mechanism is connected to the diffraction grating 201 and is used to adjust the angle of the diffraction grating 201; or, it further includes a temperature control component, which is in contact with the diffraction grating 201 and is used to adjust the angle of the diffraction grating 201.

[0056] Based on the tuning method of the diffraction grating 201 using precision mechanical rotation, other tuning mechanisms such as piezoelectric ceramic-driven angle fine-tuning of the diffraction grating 201 and temperature-controlled grating constant can also be used to control the diffraction grating 201. This allows for adjustment of the diffraction grating 201 angle through different methods, improving the flexibility of angle adjustment. Furthermore, by precisely adjusting the grating angle through the rotation mechanism, lasers with different center frequencies can be acquired at the receiving end of the first fiber collimator 202, thereby achieving continuous tunability of the center frequency.

[0057] In the above embodiments, the reconfigurable spectral filtering module 20 includes a first fiber collimator 202, a displacement stage 203, and a diffraction grating 201. To achieve transmit / receive matching, in one possible implementation, the reconfigurable spectral filtering module 20 further includes a first half-wave plate 204. For example... Figure 3 As shown. The first half-wave plate 204 is located between the diffraction grating 201 and the first fiber collimator 202, and is used to control the polarization state of the light incident on the diffraction grating 201 and transmit the controlled beam to the first fiber collimator 202.

[0058] In the reconfigurable spectral filtering module 20, the first half-wave plate 204 is disposed between the diffraction grating 201 and the first fiber collimator 202, and is used to finely control the polarization state of the light emitted from the diffraction grating 201 so that the polarization characteristics of the light match the receiving conditions of the first fiber collimator 202, thereby improving the system coupling efficiency and working stability.

[0059] Based on the laser cavity soliton microcomb system provided above, in order to achieve self-starting and stable operation of solitons, in one possible implementation, the laser cavity soliton microcomb system further includes a cavity length matching and feedback control unit 30; the cavity length matching and feedback control unit 30 is located between the output end of the reconfigurable spectral filtering module 20 and the input end of the fiber laser resonant cavity 10, and is used to adjust the total length of the fiber laser resonant cavity 10.

[0060] Specifically, the cavity length matching and feedback control unit 30 includes an optical delay line. For example... Figure 2 As shown, the input end of the optical delay line is connected to the output end of the first fiber collimator 202, and the output end of the optical delay line is connected to the input end of the fiber laser resonator 10 (specifically, to the input end of the fiber amplifier 102 in the fiber laser resonator 10), used to adjust the total length of the fiber laser resonator 10. In this laser cavity soliton microcomb system, the total length of the fiber laser cavity can be precisely adjusted through the optical delay line to accurately match its target longitudinal mode frequency with that of the microresonator 101, and the detuning of the optical field within the microcavity resonant line shape can be controlled to achieve soliton self-starting and stable operation.

[0061] To enable those skilled in the art to better understand the laser cavity soliton microcomb system provided by this invention, the following will continue to combine... Figure 2 and Figure 3The laser cavity soliton microcomb system provided by this invention will be described. Taking an erbium-doped fiber amplifier 102 as an example; a first collimating element 106 as a first convex lens; a second collimating element 107 as a second convex lens; and a microresonant cavity 101 as an FP cavity, the system will be described. It includes: an erbium-doped fiber amplifier 102, an fiber isolator 103, a second fiber collimator 104, a second half-wave plate 105, a first convex lens, an FP cavity, a second convex lens, a third half-wave plate 108, a polarization beam splitter 109, a reconfigurable spectral filter module 20, and an optical delay line. The components are connected in the following optical path sequence: the output of the erbium-doped fiber amplifier 102 is connected to the input of the fiber isolator 103 to ensure unidirectional operation of the optical field within the laser cavity. The output of the fiber isolator 103 is connected to the diverging spatial light input of the second fiber collimator 104, collimating the beam transmitted in the fiber and converting it into parallel spatial light. The collimated beam passes sequentially through the second half-wave plate 105 to adjust and select the polarization state and optical power of the incoming beam. Subsequently, the beam is focused by the first convex lens and coupled into the FP cavity, which serves as the core nonlinear element. The output light from the FP cavity is re-collimated by the second convex lens and sequentially passes through the third half-wave plate 108 and the polarization beam splitter 109 to optimize the optical path state before entering the reconfigurable spectral filtering module 20. The beam is then incident on the reconfigurable spectral filtering module 20. The tunable light is finally coupled back into the fiber optic loop, connected to the input of the optical delay line, and the output is connected back to the erbium-doped fiber amplifier 102, thus forming a complete tunable filtering and laser oscillation circuit. When the beam meets the output requirements, it is reflected by the beam-splitting surface of the polarization beam splitter 109 and then output.

[0062] Figure 3 In the reconfigurable spectral filtering module 20, the diffraction grating 201 is a reflective blazed grating. It mainly consists of a reflective blazed grating, a first half-wave plate 204, and a first fiber collimator 202. It may also include corresponding support and adjustment structures. The displacement stage 203 of the first fiber collimator 202 is used to support and precisely adjust the spatial position of the first fiber collimator 202. The reflective blazed grating is responsible for spatially separating the incident light according to wavelength; the center wavelength can be selected by rotation adjustment. The first half-wave plate 204 is used to finely control the polarization state of the light emitted from the diffraction grating 201, matching the polarization characteristics of the light with the receiving conditions of the first fiber collimator 202, improving the system coupling efficiency and operational stability. The first fiber collimator 202 is used to recouple the spatial light back into the fiber, and by adjusting its relative position with the reflective blazed grating, it can further achieve active control of the received spectral width. This module is compact and flexible in its adjustment, enabling dynamic tuning of both wavelength and bandwidth without introducing significant insertion loss. It is a key component of this system for achieving high-performance spectral management.

[0063] The laser cavity soliton microcomb system based on a reconfigurable spectral filtering module 20 provided by this invention solves the technical problems of insufficient system tuning capability and high cost caused by fixed-parameter filters in the prior art. The core solution is to replace the traditional fixed-parameter filter with a structure combining a diffraction grating 201 and an optical fiber collimator. Dynamic control of the center wavelength and spectral bandwidth is achieved by precisely adjusting the incident angle of the diffraction grating 201 and the position of the optical fiber collimator. At the same time, the synergistic effect of the diffraction grating 201 and the optical fiber collimator is used to achieve efficient filtering function.

[0064] Compared with existing technologies, this invention has the following significant advantages: it achieves adjustable center wavelength and bandwidth, greatly improving the system's adaptability to different application scenarios; by combining the diffraction grating 201 with the fiber collimator to replace the fixed filter, it significantly reduces the system's construction and maintenance costs; the compact modular design improves system integration and stability, providing an effective solution for system performance optimization; it greatly enriches the performance of the laser cavity soliton microcomb without increasing system complexity, and while retaining the low-loss and high-stability characteristics of the fiber system, the system gains a wide range and center wavelength tunable capability that traditional solutions do not possess, thereby significantly improving the flexibility of spectral management and adaptability to different application requirements, ultimately achieving high-efficiency, reconfigurable soliton microcomb output; it fundamentally breaks through the technical limitations of traditional fixed filters, providing a more advanced and flexible spectral management method for the laser cavity soliton microcomb system, significantly enhancing the system's practical value and market competitiveness.

[0065] The above describes a laser cavity soliton microcomb system. This embodiment also provides a tuning method for the laser cavity soliton microcomb system. Figure 5 A flowchart illustrating a tuning method for a laser cavity soliton microcomb system provided in an embodiment of the present invention is shown below. Figure 5 As shown, the method includes:

[0066] S10: Adjust the angle of the diffraction grating to control the center wavelength of the laser cavity soliton microcomb system;

[0067] S11: Adjust the relative position between the first fiber collimator and the diffraction grating to control the spectral bandwidth of the laser cavity soliton microcomb system.

[0068] The tuning method for the laser cavity soliton microcomb system provided in this embodiment is applied to the laser cavity soliton microcomb system. The embodiments of the laser cavity soliton microcomb system have been described in detail above, and the embodiments of the tuning method for the laser cavity soliton microcomb system will not be repeated here, and the effect is the same as above.

[0069] The foregoing has provided a detailed description of a laser cavity soliton microcomb system and its tuning method provided by the present invention. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Regarding the methods disclosed in the embodiments, since they correspond to the apparatus disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the apparatus section description. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the present invention.

[0070] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A laser cavity soliton microcomb system, characterized in that, include: A fiber laser resonator is used to provide optical amplification and establish laser oscillation. The micro-resonant cavity nested within the fiber laser resonant cavity is used to provide periodic filtering and achieve pulse shaping through Kerr nonlinearity. A reconfigurable spectral filtering module is located between the output end of the microresonator and the input end of the fiber laser resonator. It is used to perform tunable filtering on the beam emitted from the microresonator and return the tunable filtered beam to the fiber laser resonator. The reconfigurable spectral filtering module includes a diffraction grating and a first fiber collimator placed sequentially along the beam transmission direction; wherein, the center wavelength is tuned by adjusting the angle of the diffraction grating, and the spectral bandwidth is tuned by adjusting the relative position between the first fiber collimator and the diffraction grating.

2. The laser cavity soliton microcomb system according to claim 1, characterized in that, It also includes a displacement stage; the displacement stage is connected to the first fiber collimator and is used to adjust the relative position between the first fiber collimator and the diffraction grating.

3. The laser cavity soliton microcomb system according to claim 2, characterized in that, It also includes a rotating mechanism; the rotating mechanism is connected to the diffraction grating and is used to adjust the angle of the diffraction grating; Alternatively, it may also include a temperature control component, which is in contact with the diffraction grating and is used to adjust the angle of the diffraction grating.

4. The laser cavity soliton microcomb system according to claim 3, characterized in that, It also includes a first half-wave plate; the first half-wave plate is located between the diffraction grating and the first fiber collimator, and is used to control the polarization state of the light incident on the diffraction grating and transmit the controlled beam to the first fiber collimator.

5. The laser cavity soliton microcomb system according to any one of claims 1 to 4, characterized in that, It also includes a cavity length matching and feedback control unit; the cavity length matching and feedback control unit is located between the output end of the reconfigurable spectral filtering module and the input end of the fiber laser resonator, and is used to adjust the total length of the fiber laser resonator.

6. The laser cavity soliton microcomb system according to claim 5, characterized in that, The cavity length matching and feedback control unit includes an optical delay line; The input end of the optical delay line is connected to the output end of the first fiber collimator, and the output end of the optical delay line is connected to the input end of the fiber laser resonator, which is used to adjust the total length of the fiber laser resonator.

7. The laser cavity soliton microcomb system according to claim 1, characterized in that, The diffraction grating is a transmission blazed grating or a reflection blazed grating.

8. The laser cavity soliton microcomb system according to claim 5, characterized in that, The fiber laser resonant cavity includes a fiber amplifier, a fiber isolator, a second fiber collimator, a second half-wave plate, a first collimating element, a second collimating element, a third half-wave plate, and a polarization beam splitter, which are arranged sequentially along the beam transmission direction. The micro-resonant cavity is provided between the first collimating element and the second collimating element; The first output terminal of the polarization beam splitter is connected to the input terminal of the reconfigurable spectral filtering module; The second output terminal of the polarization beam splitter is used to output soliton microcomb.

9. The laser cavity soliton microcomb system according to claim 5, characterized in that, The microresonator is a Fabry-Perot microcavity, or the microresonator is an on-chip microcavity, and the quality factor of the on-chip microcavity is greater than a preset value.

10. A tuning method for a laser cavity soliton microcomb system, characterized in that, The method, applied to the laser cavity soliton microcomb system according to any one of claims 1 to 9, comprises: Adjusting the angle of the diffraction grating controls the center wavelength of the laser cavity soliton microcomb system; Adjust the relative position between the first fiber collimator and the diffraction grating to control the spectral bandwidth of the laser cavity soliton microcomb system.

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