Tunable high-repetition-frequency high-power multi-wavelength optical pulse generation system

Abstract

The invention relates to a tunable high-repetition-frequency high-power multi-wavelength optical pulse generation system, which belongs to the technical field of optoelectronic equipment and is structurally characterized in that the output end of a seed pulse source (1) is connected with the input end of a repetition-frequency multiplication module (2), and the output end of the repetition-frequency multiplication module (2) is connected with the input end of a shaping optical path module (3); the output end of the shaping light path module (3) is connected with the input end of the power amplification module (4), and the output end of the power amplification module (4) is connected with the input end of the pulse compression module (5); a multi-wavelength pulse seed source is designed by using a plurality of hybrid filters, and tunable multi-wavelength, high-repetition-frequency and high-power narrow pulse output is realized by using technologies such as an MZI-Sagnac hybrid repetition-frequency multiplication structure and the like.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic equipment technology, and specifically relates to a tunable high repetition rate, high power, multi-wavelength optical pulse generation system. Background Technology

[0002] With the rapid development of laser technology, ultrashort pulse lasers have become a core tool in modern photonics research, demonstrating enormous application potential in fields such as precision spectroscopy, optical frequency combs, laser processing, biomedical imaging, and next-generation optical communication systems. Among them, ultrashort pulse sources capable of simultaneously generating multiple wavelengths are widely favored by researchers because they can acquire multidimensional information in a single measurement or process multiple channels in parallel.

[0003] Currently, the main technological approach to achieving multi-wavelength pulse output relies on multi-wavelength fiber lasers. Traditional methods involve introducing frequency-selective elements into the laser resonant cavity, such as Sagnac ring mirrors, Lyot filters, and Mach-Zehnder interferometers (comb filters). These periodic filtering characteristics excite laser oscillations of multiple wavelengths within the bandwidth of the gain medium. However, these lasers based on linear filtering mechanisms are generally limited by strong mode competition and uniform broadening effects within the fiber, resulting in low output power and poor wavelength stability. Stable continuous-wave output is particularly difficult to achieve at room temperature, let alone stable mode-locked pulse output.

[0004] To overcome mode competition, researchers have developed nonlinear effect-assisted multiwavelength laser techniques, such as using nonlinear polarization rotation or nonlinear optical ring mirrors to achieve mode locking. Combined with the properties of gain media like erbium-doped fiber, relatively stable multiwavelength pulse sequences can be obtained at room temperature. However, the pulses generated by these systems typically have the following inherent limitations: First, the repetition frequency is low, mostly in the megahertz range, due to limitations in the physical length of the resonant cavity. High repetition frequency often means a short cavity length, which sacrifices single-pulse energy and increases the difficulty of mode locking. Second, the output power is limited. As a direct output from an oscillator, the pulse energy is usually below nanojoules, making it difficult to meet the needs of many applications requiring high photon flux or strong nonlinear interactions. Third, the wavelength tuning capability is insufficient and coupled with power and repetition frequency parameters. Traditional tuning methods, such as adjusting the polarization state within the filter, often simultaneously affect the mode-locking state and output power, leading to a complex tuning process and unstable output performance.

[0005] To increase the repetition rate, existing technologies typically employ external repetition rate multiplication schemes, such as using a Mach-Zehnder interferometer to perform time-domain replication and interleaving of the pulse sequence. However, simple cascaded MZI introduces significant insertion loss, and the multiplication process may disrupt the relative timing and phase relationships between multi-wavelength pulses, leading to pulse waveform degradation. To increase output power, an optical fiber amplifier needs to be cascaded after the oscillator, but this introduces new challenges: nonlinear effects during amplification can broaden the spectrum, distort the pulse, and potentially exacerbate gain competition between multiple wavelengths, disrupting the original multi-wavelength state, or even causing a degradation from multi-wavelength output to a single-wavelength or wavelength-switching unstable state.

[0006] In summary, there are still many challenges in obtaining high-repetition-rate, high-power, multi-wavelength output fiber laser systems. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention aims to provide a tunable high-repetition-rate, high-power multi-wavelength optical pulse generation system. Its main objective is to solve the technical challenge of simultaneously achieving flexible wavelength tuning, high repetition rate, and high output power in existing technologies. It overcomes the drawbacks of multi-wavelength pulses being prone to instability during amplification, the degradation of pulse quality by traditional repetition-multiplication techniques, and tuning difficulties caused by the coupling of system parameters. The system obtains initial multi-wavelength pulses through a seed pulse source, increases the pulse repetition rate through a repetition-multiplication module, and then obtains a high-power, stable pulse output through a power amplification module and a pulse compression module.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A tunable high-repetition-rate, high-power, multi-wavelength optical pulse generation system is disclosed. Its structure comprises: the output of a seed pulse source 1 connected to the input of a repetition-rate multiplication module 2; the output of the repetition-rate multiplication module 2 connected to the input of a shaping optical path module 3; the output of the shaping optical path module 3 connected to the input of a power amplification module 4; and the output of the power amplification module 4 connected to the input of a pulse compression module 5. The seed pulse source 1 employs a shared laser resonant cavity structure, internally integrating a Sagnac ring and a Lyot-type filter branch in parallel. It utilizes a high-birefringence fiber and a polarization controller to jointly regulate the transmission wavelength, achieving flexible tuning of multi-wavelength output. This is combined with non-... A linear mode-locking mechanism and a multimode saturable absorber achieve self-starting mode-locking through nonlinear phase shift accumulation, effectively suppressing mode competition among multiple wavelengths; providing an ultrashort pulse seed source with independently tunable wavelength and high stability for the repetition rate multiplier module 2; the repetition rate multiplier module 2 adopts a hybrid structure combining a Sagnac ring and an asymmetric MZI. The Sagnac ring, based on the principle of polarization interference, preprocesses each input pulse into a pulse pair with a fixed time delay. The pulse pair is injected into the asymmetric MZI. By precisely controlling the optical path difference between the two arms and utilizing the constructive and destructive effects of interference, the time-domain interleaving and synthesis of multiple pulses are realized, thereby efficiently increasing the repetition rate.

[0010] The seed pulse source 1 has the following structure: a first pump source 101 is connected to the 980nm end of a first wavelength division multiplexer 102; the common end of the first wavelength division multiplexer 102 is connected to the input end of a first coupler 105 via a first erbium-doped fiber 103 and a first polarization-independent optical isolator 104; the 50% output end of the first coupler 105 is connected to a first polarizer 106; the optical pulse passes through the first polarizer 106, the first polarization controller 107, the first polarization-maintaining fiber 108, the second polarization controller 109, and the second polarizer 110, and is then connected to the 50% input end of the second coupler 111; the other 50% output end of the first coupler 105 is connected to the 50% input end of a third coupler 112; the 50% output end of the third coupler 112 is connected to a third polarization controller 113; and the third polarization controller 113 is connected to a first high-birefringence fiber 114. The first high birefringence fiber 114 is connected to the fourth polarization controller 115. The fourth polarization controller 115 is connected to the second high birefringence fiber 116. The second high birefringence fiber 116 is connected to the other 50% input terminal of the third coupler 112. The other 50% output terminal of the third coupler 112 is connected to the first fiber delay line 117. The first fiber delay line 117 is connected to the other 50% input terminal of the second coupler 111. The optical pulse is output from the output terminal of the second coupler 111 through the fifth polarization controller 118 and the squeeze polarization controller 119 containing SMF-GIMF-SMF. The squeeze polarization controller 119 is connected to the input terminal of the fourth coupler 120. The 80% output terminal of the fourth coupler 120 is connected to the other common terminal of the first wavelength division multiplexer 102. The optical pulse is output from the 20% output terminal of the fourth coupler 120.

[0011] The frequency repetition rate multiplier module 2 has the following optical path structure: the optical pulse passes through the second polarization-independent optical isolator 201 and the sixth polarization controller 202. The sixth polarization controller 202 is connected to the input of the fifth coupler 203. The 50% output of the fifth coupler 203 is connected to the first single-mode fiber 204. The first single-mode fiber 204 is connected to the seventh polarization controller 205. The seventh polarization controller 205 is connected to the input of the sixth coupler 206. The output of the sixth coupler 206 is connected to the second fiber delay line 209. The second fiber delay line 209 is connected to the eighth polarization controller 208. The controller 208 is connected to the third high birefringence fiber 207, which is connected to another input of the sixth coupler 206. The other output of the sixth coupler 206 is connected to the input of the seventh coupler 210. The other output of the fifth coupler 203 is connected to the second single-mode fiber 211, which is connected to the third fiber delay line 212. The third fiber delay line 212 is connected to the ninth polarization controller 213, which is connected to another input of the seventh coupler 210. Finally, the optical pulse is output from the output of the seventh coupler 210.

[0012] The shaping optical path module 3 has the following optical path structure: the light pulse is transmitted to the first half-wave plate 301, and after being reflected by the first reflector 302 and the second reflector 303, it enters the first beam expander 304. After passing through the first beam expander 304, the light pulse is reflected by the third reflector 305 to the first spatial light modulator 306. The beam modulated by the first spatial light modulator 306 passes through the first convex lens 307, the second convex lens 308, and the unpolarized beam splitter 309. One beam of light passing through the unpolarized beam splitter 309 is focused by the third convex lens 310 and then incident on the first feedback device 311. The other beam of light passing through the unpolarized beam splitter 309 is focused by the fourth convex lens 312 and then output after passing through the fourth reflector 313.

[0013] The power amplifier module 4 has the following optical path structure: the light pulse is transmitted through a semiconductor saturable absorber mirror 401 (SESAM) to a passive optical fiber 402, a second erbium-doped optical fiber 403, and is connected to the input end of a first fiber Bragg grating 404. The output end of the first fiber Bragg grating 404 is connected to the common end of a second wavelength division multiplexer 405. The 980nm end of the second wavelength division multiplexer 405 is connected to a second pump source 406. The other common end of the second wavelength division multiplexer 405 is connected to the input end of a third isolator 407. The light output from the output end of the third isolator 407 passes through a fifth reflector 408, a sixth reflector 409, a fifth convex lens 410, a sixth convex lens 411, an input mirror 412, and a first Erbium-doped optical fiber 404. The system consists of a YAP crystal 413, an eighth coupler 414, a first bandpass filter 415, a third polarizer 416, a seventh convex lens 417, a dichroic mirror 418, and a third pump source 419 connected to the 980nm end of the third wavelength division multiplexer 420. The optical pulse originates from the common end of the third wavelength division multiplexer 420, passes through the eighth convex lens 421, the ninth convex lens 422, and the dichroic mirror 418, and is output after passing through the dichroic mirror 418 and the second Er: YAP crystal 423 and the second bandpass filter 424.

[0014] The pulse compression module 5 has the following optical path structure: the light pulse is incident on the second polarization beam splitter 502 after passing through the first polarization beam splitter 501. A portion of the light pulse after passing through the second polarization beam splitter 502 is transmitted to the seventh reflector 503. After being reflected by the seventh reflector 503, the light pulse is sequentially reflected by the eighth reflector 504, the ninth reflector 505, and the tenth reflector 506. The light pulse reflected by the tenth reflector 506 is incident on the first grating 512. The first grating 512 reflects the light pulse to the second grating 513. The second grating 513 reflects the light pulse to the eleventh reflector 514. After reaching the eleventh reflector 514, the light pulse follows the input path. The light pulse is reflected back to the first grating 512, which transmits it to the twelfth mirror 515. The light pulse is then reflected by the twelfth mirror 515 to the thirteenth mirror 517, and then incident on the tenth convex lens 535. Another portion of the light pulse output from the second polarizing beam splitter 502 is transmitted to the fourteenth mirror 507. After being reflected by the fourteenth mirror 507, the light pulse passes sequentially through the fifteenth mirror 508, the sixteenth mirror 509, the seventeenth mirror 510, and the eighteenth mirror 511. The light pulse reflected by the eighteenth mirror 511 enters the first grating 512 parallel to the light pulse reflected by the tenth mirror 506. As described above, the incident path of the light pulse from the tenth reflector 506 to the first grating 512 sequentially passes through the first grating 512, the second grating 513, and the eleventh reflector 514, and returns to the first grating 512 along the input path. The light pulse is then transmitted from the first grating 512 to the twelfth reflector 515, reflected by the twelfth reflector 515 to the nineteenth reflector 516, and incident on the tenth convex lens 535. The light pulse is then transmitted from the other output end of the first polarizing beam splitter 501 to the twentieth reflector 518, and then transmitted to the third polarizing beam splitter 519. A portion of the light pulse after passing through the third polarizing beam splitter 519 is transmitted to the twenty-first reflector 520, and reflected by the twenty-first reflector 520. The light pulse is then reflected sequentially by the twenty-second reflector 521, the twenty-third reflector 522, and the twenty-fourth reflector 523. The light pulse reflected by the twenty-fourth reflector 523 is incident on the third grating 529, which reflects it to the fourth grating 530. The fourth grating 530 reflects it to the twenty-fifth reflector 531. After reaching the twenty-fifth reflector 531, the light pulse is reflected back to the third grating 529 along the input path. The third grating 529 transmits the light pulse to the twenty-sixth reflector 532, which reflects it to the twenty-seventh reflector 534. The twenty-seventh reflector 534 reflects it to the tenth convex lens 535. Another portion of the light pulse output from the third polarizing beam splitter 519 is transmitted to the twenty-eighth reflector 524.After being reflected by the twenty-eighth reflector 524, the light pulse passes sequentially through the twenty-ninth reflector 525, the thirtieth reflector 526, the thirty-first reflector 527, and the thirty-second reflector 528. The light pulse reflected by the thirty-second reflector 528 enters the third grating 529 parallel to the light pulse reflected by the twenty-fourth reflector 523. As described above, the incident path of the light pulse from the twenty-fourth reflector 523 to the third grating 529 passes sequentially through the third grating 529, the fourth grating 530, and the twenty-fifth reflector 531, and returns to the third grating 529 along the input path. The light pulse is then transmitted from the third grating 529 to the twenty-sixth reflector 532, and reflected by the twenty-sixth reflector 532 to the thirty-third reflector 533. The light pulses, reflected by the thirty-third mirror 533 to the tenth convex lens 535, and then passing through the nineteenth mirror 516, the thirteenth mirror 517, the twenty-seventh mirror 534, and the thirty-third mirror 533 respectively, enter the tenth convex lens 535 in parallel. After being focused by the tenth convex lens 535, the light pulses are merged. The merged light pulse is then reflected by the thirty-fourth mirror 536 to the thirty-fifth mirror 537. After passing through the thirty-fifth mirror 537, the light pulse is transmitted to the second half-wave plate 538. After passing through the second half-wave plate 538, the light pulse is reflected by the thirty-sixth mirror 539 to the second spatial light modulator 540. The light beam modulated by the second spatial light modulator 540 passes through the eleventh convex lens 541 and the twelfth convex lens 542. The thirteenth convex lens 543 focuses the light pulse onto the second feedback device 544. The light pulse is then transmitted from the second feedback device 544 to the thirty-seventh reflecting mirror 545, the thirty-eighth reflecting mirror 546, and the third half-wave plate 547. After passing through the third half-wave plate 547, the light pulse is incident on the fourth polarizing beam splitter 548. The light pulse output from the output end of the fourth polarizing beam splitter 548, which is parallel to the incident direction, is transmitted to the thirty-ninth reflecting mirror 549. The light pulse is reflected by the thirty-ninth reflecting mirror 549 to the fortieth reflecting mirror 550. The light pulse is reflected by the fortieth reflecting mirror 550 to the first concave mirror 552. After passing through the first concave mirror 552 and the LBO crystal 553, the light pulse is incident on the second concave mirror 554. After passing through the second concave mirror 554, the light pulse is incident on the forty-first reflecting mirror 555. After being reflected by the forty-first reflector 555 to the third concave mirror 556, the light pulse output from the third concave mirror 556 passes through the BBO crystal 557 and is incident on the fourth concave mirror 558. The light pulse is reflected by the fourth concave mirror 558 to the forty-second reflector 551 and then incident on the first concave mirror 552. After passing through the first concave mirror 552, the light pulse again passes through the first concave mirror 552, LBO crystal 553, second concave mirror 554, forty-first reflector 555, third concave mirror 556, BBO crystal 557, and fourth concave mirror 558 according to the above-described path. After multiple reflections, the light pulse returns to the fourth concave mirror 558 and is transmitted through the fourth concave mirror 558 to the fourteenth convex lens 559 for output.

[0015] Beneficial effects:

[0016] 1. This invention utilizes multiple hybrid filters to design a multi-wavelength pulse seed source, thereby achieving tunable multi-wavelength output.

[0017] 2. This invention utilizes a hybrid design of MZI-Sagnac to create a high repetition rate multiplier structure, thereby achieving high repetition rate pulse output.

[0018] 3. This invention utilizes optical lenses, optical modulators, etc., to modulate spatial light and achieve high-power narrow pulse output.

[0019] 4. This invention utilizes a combination of nonlinear crystal barium metaborate and lithium triborate, and employs optical lenses to design multi-stage, multi-path pulse compression, thereby ensuring stable multi-wavelength ultrashort pulse output through pulse compression. Attached Figure Description

[0020] Figure 1 This is a block diagram of the overall structure of the present invention.

[0021] Figure 2 This is the optical path diagram of the seed pulse source used in this invention.

[0022] Figure 3 This is the optical path diagram of the frequency multiplication module used in this invention.

[0023] Figure 4 This is the optical path diagram of the shaping optical path module used in this invention.

[0024] Figure 5 This is the optical path diagram of the power amplifier module used in this invention.

[0025] Figure 6 This is the optical path diagram of the pulse compression module used in this invention.

[0026] Figure 7 This is the spectrum output by the seed pulse source 1 of this invention.

[0027] Figure 8 This is the spectrum diagram of the output of the seed pulse source 1 of this invention.

[0028] Figure 9 This is the spectrum output by the frequency multiplication module 2 of the present invention.

[0029] Figure 10 This is the autocorrelation diagram output by the pulse compression module 5 of this invention. Detailed Implementation

[0030] The working principle of the present invention will be further explained below with reference to the accompanying drawings. It should be understood that the component parameters marked in the embodiments are preferred parameters used in each embodiment, rather than limitations on the scope of protection.

[0031] Example 1: Overall Structure of the Invention

[0032] like Figure 1 As shown, the overall structural block diagram of the present invention is as follows: Figure 1 As shown: the output of seed pulse source 1 is connected to the input of repetition rate multiplier module 2, the output of repetition rate multiplier module 2 is connected to the input of shaping optical path module 3, the output of shaping optical path module 3 is connected to the input of power amplifier module 4, and the output of power amplifier module 4 is connected to the input of pulse compression module 5. Seed pulse source 1 adopts a shared laser resonant cavity structure, internally integrating a Sagnac ring and a Lyot-type filter branch in parallel. It utilizes a high birefringence fiber and a polarization controller to jointly regulate the transmission wavelength, achieving flexible tuning of multi-wavelength output. Combining a nonlinear mode-locking mechanism and a multimode saturable absorber, it achieves self-starting mode-locking through nonlinear phase shift accumulation, effectively suppressing mode competition between multiple wavelengths. It provides an ultrashort pulse seed source with independently tunable wavelength and high stability for repetition rate multiplication module 2. Repetition rate multiplication module 2 adopts a hybrid structure combining a Sagnac ring and an asymmetric MZI. The Sagnac ring, based on the principle of polarization interference, preprocesses each input pulse into a pulse pair with a fixed time delay. The pulse pair is injected into the asymmetric MZI. By precisely controlling the optical path difference between the two arms and utilizing the constructive and destructive effects of interference, the time-domain interleaving and synthesis of multiple pulses are achieved, thereby efficiently increasing the repetition rate.

[0033] Example 2 Seed Pulse Source

[0034] The optical path diagram of the seed pulse source 1 is as follows: Figure 2As shown, its structure is as follows: the first pump source 101 is connected to the 980nm end of the first wavelength division multiplexer 102; the common end of the first wavelength division multiplexer 102 is connected to the input end of the first coupler 105 via the first erbium-doped fiber 103 and the first polarization-independent optical isolator 104; the 50% output end of the first coupler 105 is connected to the first polarizer 106; the optical pulse passes through the first polarizer 106, the first polarization controller 107, the first polarization-maintaining fiber 108, the second polarization controller 109, and the second polarizer 110, and is then connected to the 50% input end of the second coupler 111; the other 50% output end of the first coupler 105 is connected to the 50% input end of the third coupler 112; the 50% output end of the third coupler 112 is connected to the third polarization controller 113; the third polarization controller 113 is connected to the first high birefringence fiber 114; and so on. A high birefringence fiber 114 is connected to a fourth polarization controller 115. The fourth polarization controller 115 is connected to a second high birefringence fiber 116. The second high birefringence fiber 116 is connected to the other 50% input of a third coupler 112. The other 50% output of the third coupler 112 is connected to a first fiber delay line 117. The first fiber delay line 117 is connected to the other 50% input of a second coupler 111. The optical pulse is emitted from the output of the second coupler 111 through a fifth polarization controller 118 and a squeeze polarization controller 119 containing an SMF-GIMF-SMF. The squeeze polarization controller 119 is connected to the input of a fourth coupler 120. The 80% output of the fourth coupler 120 is connected to the other common terminal of a first wavelength division multiplexer 102. The optical pulse is emitted from the 20% output of the fourth coupler 120. Seed pulse source 1 uses parallel independent filtering branches within a shared laser resonant cavity, namely a Sagnac ring filter and a Lyot filter. Its transmission wavelength is determined by the fiber length and birefringence. The output wavelength can be tunable by adjusting the polarization controller. Seed pulse source 1 is mode-locked using a multimode saturable absorber, and nonlinear effects apply to all wavelength components. Simultaneously, the structure of seed pulse source 1 helps suppress mode competition between different wavelengths, and its shared cavity structure ensures inherent temporal synchronization and coherence of pulses of different wavelengths. Furthermore, independent and flexible wavelength tuning can be achieved by adjusting the filtering branches, providing a high-quality, highly stable multi-wavelength ultrashort pulse seed source for the entire system. The output spectrum of this embodiment is shown below. Figure 7 As shown, the center wavelengths of the spectra are 1549.08 nm and 1567.52 nm, with 3dB bandwidths of 4.55 nm and 4.28 nm, respectively. The spectrum output in this embodiment is shown below. Figure 8 As shown, the repetition frequency is 23.4MHz and the output power is around 150mW.

[0035] Example 3: Frequency Multiplication Module

[0036] The optical path structure of the frequency multiplication module 2 is as follows: Figure 3 As shown: The optical pulse passes through the second polarization-independent optical isolator 201 and the sixth polarization controller 202. The sixth polarization controller 202 is connected to the input of the fifth coupler 203. The 50% output of the fifth coupler 203 is connected to the first single-mode fiber 204. The first single-mode fiber 204 is connected to the seventh polarization controller 205. The seventh polarization controller 205 is connected to the input of the sixth coupler 206. The output of the sixth coupler 206 is connected to the second fiber delay line 209. The second fiber delay line 209 is connected to the eighth polarization controller 208. The eighth polarization controller 208 is connected to the... The third high-birefringence fiber 207 is connected to another input of the sixth coupler 206, and the other output of the sixth coupler 206 is connected to the input of the seventh coupler 210. The other output of the fifth coupler 203 is connected to the second single-mode fiber 211, which is connected to the third fiber delay line 212. The third fiber delay line 212 is connected to the ninth polarization controller 213, which is connected to the other input of the seventh coupler 210. Finally, the optical pulse is output from the output of the seventh coupler 210. Through a Sagnac ring with a built-in high-birefringence fiber, each input single pulse is preprocessed in the time domain into a pulse pair with a fixed interval. Then, this pulse pair is injected into an asymmetric MZI. By precisely controlling the optical path difference between its two arms, the sub-pulses from different original pulses are rearranged and interleaved in the time domain, thereby synthesizing a new pulse sequence with a multiplied repetition frequency. This module achieves a higher single-stage multiplication factor with fewer stages through a collaborative design of a hybrid architecture, significantly reducing total insertion loss and timing jitter. The spectrum output by this embodiment is shown below. Figure 9 As shown, the repetition frequency is 70.5MHz, which is a doubling of the repetition frequency compared to the output repetition frequency in Example 2.

[0037] Example 4: Shaping Optical Path Module

[0038] The optical path structure of the shaping optical path module 3 is as follows: Figure 4As shown: The light pulse is transmitted to the first half-wave plate 301, reflected by the first reflector 302 and the second reflector 303, and then enters the first beam expander 304. After passing through the first beam expander 304, the light pulse is reflected by the third reflector 305 to the first spatial light modulator 306. The beam modulated by the first spatial light modulator 306 passes through the first convex lens 307, the second convex lens 308, and the unpolarized beam splitter 309. One beam of light passing through the unpolarized beam splitter 309 is focused by the third convex lens 310 and then enters the first feedback device 311. The other beam of light passing through the unpolarized beam splitter 309 is focused by the fourth convex lens 312 and then output after passing through the fourth reflector 313. By precisely controlling the wavefront of the beam through the spatial light modulator, the amplitude, phase, and polarization state of the light pulse can be actively controlled, improving the system's adaptability to complex applications. The combination of the beam expander and the convex lens effectively suppresses diffraction effects and ensures beam uniformity and collimation. Part of the beam is monitored and controlled in real time through a feedback device to improve output stability and achieve effective conversion from fiber output to spatial optical path, thereby realizing beam expansion, collimation and splitting, and optimizing beam quality.

[0039] Example 5: Power Amplification Module

[0040] The optical path structure of the power amplifier module 4 is as follows: Figure 5As shown: The optical pulse is transmitted through a semiconductor saturable absorber mirror 401 (SESAM) to a passive optical fiber 402, a second erbium-doped optical fiber 403, and is connected to the input end of a first fiber Bragg grating 404. The output end of the first fiber Bragg grating 404 is connected to the common end of a second wavelength division multiplexer 405. The 980nm end of the second wavelength division multiplexer 405 is connected to a second pump source 406. The other common end of the second wavelength division multiplexer 405 is connected to the input end of a third isolator 407. The light output from the third isolator 407 passes through a fifth reflector 408, a sixth reflector 409, a fifth convex lens 410, a sixth convex lens 411, an input mirror 412, and a first Erbium-doped optical fiber 404. The system consists of a YAP crystal 413, an eighth coupler 414, a first bandpass filter 415, a third polarizer 416, a seventh convex lens 417, a dichroic mirror 418, and a third pump source 419 connected to the 980nm end of the third wavelength division multiplexer 420. Optical pulses originate from the common end of the third wavelength division multiplexer 420, pass through the eighth convex lens 421, the ninth convex lens 422, and the dichroic mirror 418, and are then output after passing through the second Er:YAP crystal 423 and the second bandpass filter 424. The power amplifier module 4 combines the advantages of fiber optics and solid-state amplifiers, balancing high gain and high energy output. During amplification, it effectively suppresses gain competition between wavelengths, avoiding multi-wavelength output degradation. Through multi-stage isolators, filters, and polarization control, it ensures stable amplification, high output power, and low fluctuation. The use of multiple pump sources and wavelength division multiplexers improves energy conversion efficiency, resulting in an output power of approximately 1W.

[0041] Example 6: Pulse Compression Module

[0042] The optical path structure of the pulse compression module 5 is as follows: Figure 6As shown: A light pulse is incident on a first polarizing beam splitter 501 and then on a second polarizing beam splitter 502. A portion of the light pulse after passing through the second polarizing beam splitter 502 is transmitted to a seventh reflecting mirror 503. After being reflected by the seventh reflecting mirror 503, the light pulse is sequentially reflected by an eighth reflecting mirror 504, a ninth reflecting mirror 505, and a tenth reflecting mirror 506. The light pulse reflected by the tenth reflecting mirror 506 is incident on a first grating 512. The first grating 512 reflects the light pulse to a second grating 513. The second grating 513 reflects the light pulse to an eleventh reflecting mirror 514. After reaching the eleventh reflecting mirror 514, the light pulse is reflected back to the first grating 512 along the input path. The first grating 512 then transmits the light pulse to a twelfth reflecting mirror. The light pulse is reflected by the twelfth mirror 515 to the thirteenth mirror 517, and then incident on the tenth convex lens 535. Another portion of the light pulse output from the second polarizing beam splitter 502 is transmitted to the fourteenth mirror 507. After being reflected by the fourteenth mirror 507, the light pulse passes sequentially through the fifteenth mirror 508, the sixteenth mirror 509, the seventeenth mirror 510, and the eighteenth mirror 511. The light pulse reflected by the eighteenth mirror 511 enters the first grating 512 parallel to the light pulse reflected by the tenth mirror 506. As described above, the incident path of the light pulse incident from the tenth mirror 506 to the first grating 512 sequentially passes through the first grating 512, the fifteenth mirror 508, the sixteenth mirror 509, the seventeenth mirror 510, and the eighteenth mirror 511. The light pulse passes through the second grating 513 and the eleventh reflector 514, then returns to the first grating 512 along the input path. The light pulse is transmitted from the first grating 512 to the twelfth reflector 515, reflected by the twelfth reflector 515 to the nineteenth reflector 516, and then incident on the tenth convex lens 535. The light pulse is then transmitted from the other output of the first polarization beam splitter 501 to the twentieth reflector 518, and then to the third polarization beam splitter 519. A portion of the light pulse after passing through the third polarization beam splitter 519 is transmitted to the twenty-first reflector 520, and after reflection by the twenty-first reflector 520, it passes sequentially through the twenty-second reflector 521 and the twenty-third reflector 525. 22. The light pulse reflected by the twenty-fourth reflector 523 is incident on the third grating 529. The third grating 529 reflects the light pulse to the fourth grating 530, which in turn reflects it to the twenty-fifth reflector 531. After reaching the twenty-fifth reflector 531, the light pulse is reflected back to the third grating 529 along the input path. The third grating 529 transmits the light pulse to the twenty-sixth reflector 532, which reflects it to the twenty-seventh reflector 534. The twenty-seventh reflector 534 then reflects it to the tenth convex lens 535. Another portion of the light pulse output from the third polarization beam splitter 519 is transmitted to the twenty-eighth reflector 524.After being reflected by the twenty-eighth reflector 524, the light pulse passes sequentially through the twenty-ninth reflector 525, the thirtieth reflector 526, the thirty-first reflector 527, and the thirty-second reflector 528. The light pulse reflected by the thirty-second reflector 528 enters the third grating 529 in parallel with the light pulse reflected by the twenty-fourth reflector 523. As described above, the incident path of the light pulse from the twenty-fourth reflector 523 to the third grating 529 sequentially passes through the third grating 529, the fourth grating 530, and the twenty-fifth reflector 531, and returns to the third grating 529 along the input path. The light pulse is then transmitted from the third grating 529 to the twenty-sixth reflector 532, and reflected by the twenty-sixth reflector 532 to the thirty-third reflector 53. 3. The light pulses reflected by the thirty-third mirror 533 are reflected to the tenth convex lens 535. The four light pulses, which pass through the nineteenth mirror 516, the thirteenth mirror 517, the twenty-seventh mirror 534, and the thirty-third mirror 533 respectively, enter the tenth convex lens 535 in parallel. After being focused by the tenth convex lens 535, the light pulses are merged. The merged light pulse is reflected by the thirty-fourth mirror 536 to the thirty-fifth mirror 537. After passing through the thirty-fifth mirror 537, the light pulse is transmitted to the second half-wave plate 538. After passing through the second half-wave plate 538, the light pulse is reflected by the thirty-sixth mirror 539 to the second spatial light modulator 540. The light beam modulated by the second spatial light modulator 540 passes through the eleventh convex lens 541 and the twelfth convex lens. 542. The thirteenth convex lens 543 focuses the light pulse onto the second feedback device 544. The light pulse is transmitted from the second feedback device 544 to the thirty-seventh reflecting mirror 545, the thirty-eighth reflecting mirror 546, and the third half-wave plate 547. After passing through the third half-wave plate 547, the light pulse is incident on the fourth polarizing beam splitter 548. The light pulse output from the output end of the fourth polarizing beam splitter 548, which is parallel to the incident direction, is transmitted to the thirty-ninth reflecting mirror 549. The light pulse is reflected by the thirty-ninth reflecting mirror 549 to the fortieth reflecting mirror 550. The light pulse is reflected by the fortieth reflecting mirror 550 to the first concave mirror 552. After passing through the first concave mirror 552 and the LBO crystal 553, the light pulse is incident on the second concave mirror 554. After passing through the second concave mirror 554, the light pulse is incident on the forty-first reflecting mirror. The light pulse is reflected by mirror 555 to the third concave mirror 556. The light pulse output from the third concave mirror 556 passes through the BBO crystal 557 and is incident on the fourth concave mirror 558. The light pulse is reflected by the fourth concave mirror 558 to the forty-second mirror 551 and then incident on the first concave mirror 552. After passing through the first concave mirror 552, the light pulse again passes through the first concave mirror 552, LBO crystal 553, second concave mirror 554, forty-first mirror 555, third concave mirror 556, BBO crystal 557, and fourth concave mirror 558, following the route described above. After multiple reflections, the light pulse returns to the fourth concave mirror 558 and is transmitted through the fourth concave mirror 558 to the fourteenth convex lens 559.Optical pulse output. Pulse compression module 5 combines grating pairs and a nonlinear crystal to achieve strong dispersion compensation and pulse width compression. Frequency conversion is achieved through LBO and BBO crystals, supporting wavelength tuning and extension. Feedback control and multi-mirror path design ensure consistent output pulse timing, significantly improving compression efficiency and stability, making the output multi-wavelength pulses more stable. The autocorrelation diagram output in this embodiment is shown below. Figure 10 As shown, the pulse width at this time is 0.26 ps.

[0043] Example 7: Working principle of the present invention

[0044] The working principle of the present invention will be explained in conjunction with the above embodiments and accompanying drawings.

[0045] Seed pulse source 1 uses a shared laser resonant cavity with parallel independent filtering branches, namely a Sagnac ring filter and a Lyot filter. Its transmission wavelength is determined by the fiber length and birefringence. The output wavelength can be tunable by adjusting the polarization controller. Seed pulse source 1 is mode-locked using a multimode saturable absorber, and its nonlinear effect applies to all wavelength components. Simultaneously, the structure of seed pulse source 1 helps suppress mode competition between different wavelengths, and its shared cavity structure ensures inherent temporal synchronization and coherence of pulses of different wavelengths. Furthermore, independent and flexible wavelength tuning can be achieved by adjusting the filtering branches, providing a high-quality, highly stable multi-wavelength ultrashort pulse seed source for the entire system. The frequency multiplication module 2 uses a Sagnac ring with a built-in high birefringence fiber to preprocess each input single pulse into a pulse pair with a fixed interval in the time domain. Then, this pulse pair is injected into an asymmetric MZI. By precisely controlling the optical path difference between its two arms, the sub-pulses from different original pulses are rearranged and interleaved in the time domain, thereby synthesizing a new pulse sequence with a multiplied repetition frequency. This module, through a collaborative design of a hybrid architecture, achieves a higher single-stage multiplication factor with fewer stages, significantly reducing total insertion loss and timing jitter. The shaping optical path module 3 uses a spatial light modulator to precisely control the wavefront of the beam, enabling active control of the amplitude, phase, and polarization state of the optical pulses, improving the system's adaptability to complex applications. A combination of beam expanders and convex lenses effectively suppresses diffraction effects, ensuring beam uniformity and collimation. Part of the beam is monitored in real-time and controlled in a closed-loop manner through a feedback device, improving output stability and achieving effective conversion from fiber output to the spatial optical path, realizing beam expansion, collimation, and splitting, and optimizing beam quality. The power amplifier module 4 combines the advantages of fiber optics and solid-state amplifiers, balancing high gain and high energy output. During amplification, it effectively suppresses gain competition between wavelengths, avoiding multi-wavelength output degradation. Through multi-stage isolators, filters, and polarization control, it ensures stable amplification, high output power, and low fluctuation. Multiple pump sources and wavelength division multiplexers are used to improve energy conversion efficiency. The pulse compression module 5 combines grating pairs and nonlinear crystals to achieve strong dispersion compensation and pulse width compression. Frequency conversion is achieved through LBO and BBO crystals, supporting wavelength tuning and extension. Feedback control and multi-mirror path design ensure consistent output pulse timing, significantly improving compression efficiency and stability, resulting in more stable multi-wavelength pulses.

Claims

1. A tunable high-repetition-rate high-power multi-wavelength optical pulse generation system, which is structured as follows: the output end of a seed pulse source (1) is connected with the input end of a repetition rate multiplication module (2), the output end of the repetition rate multiplication module (2) is connected with the input end of a shaping optical path module (3), the output end of the shaping optical path module (3) is connected with the input end of a power amplification module (4), and the output end of the power amplification module (4) is connected with the input end of a pulse compression module (5); characterized in that, The seed pulse source (1) adopts a shared laser resonant cavity structure, internally parallelly integrates a Sagnac loop and a Lyot type filtering branch, utilizes a high birefringence fiber and a polarization controller to jointly regulate and control a transmission wavelength, realizes flexible tuning of multi-wavelength output, combines a nonlinear mode-locking mechanism and a multimode saturable absorber, and realizes self-starting mode-locking through nonlinear phase shift accumulation to effectively suppress mode competition among multiple wavelengths; the frequency multiplication module (2) is provided with a wavelength independently tunable, high stability ultrashort pulse seed source; the frequency multiplication module (2) adopts a hybrid structure combining a Sagnac loop and an asymmetric MZI, the Sagnac loop pre-processes each input pulse into a pulse pair with a fixed time delay based on the polarization interference principle, the pulse pair is injected into the asymmetric MZI, the optical path difference of two arms is accurately controlled, and the interference constructive and destructive effects are utilized to realize time domain interleaving and synthesis of multiple pulses, so that the repetition frequency is effectively improved.

2. The system of claim 1, wherein, The structure of the seed pulse source (1) is as follows: the first pump source (101) is connected with the 980nm end of the first wavelength division multiplexer (102), the common end of the first wavelength division multiplexer (102) is connected with the input end of the first coupler (105) through the first erbium-doped fiber (103) and the first polarization-independent optical isolator (104), the 50% output end of the first coupler (105) is connected with the first polarizer (106), the optical pulse is connected with the 50% input end of the second coupler (111) after passing through the first polarizer (106), the first polarization controller (107), the first polarization maintaining fiber (108), the second polarization controller (109), and the second polarizer (110); the other 50% output end of the first coupler (105) is connected with the 50% input end of the third coupler (112), the 50% output end of the third coupler (112) is connected with the third polarization controller (113), the third polarization controller (113) is connected with the first high birefringence fiber (114), the first high birefringence fiber (114) is connected with the fourth polarization controller (115), the fourth polarization controller (115) is connected with the second high birefringence fiber (116), the second high birefringence fiber (116) is connected with the other 50% input end of the third coupler (112), the other 50% output end of the third coupler (112) is connected with the first fiber delay line (117), the first fiber delay line (117) is connected with the other 50% input end of the second coupler (111), the optical pulse is output from the output end of the second coupler (111) after passing through the fifth polarization controller (118), the extruded polarization controller (119) containing SMF-GIMF-SMF, the extruded polarization controller (119) is connected with the input end of the fourth coupler (120), the 80% output end of the fourth coupler (120) is connected with the other common end of the first wavelength division multiplexer (102), and the optical pulse is output from the 20% output end of the fourth coupler (120).

3. The tunable high repetition rate, high power, multi-wavelength optical pulse generation system according to claim 1, characterized in that, The heavy frequency multiplication module (2) has the following optical path structure: the light pulse passes through a second polarization-independent optical isolator (201), a sixth polarization controller (202), the sixth polarization controller (202) is connected with the input end of a fifth coupler (203), 50% of the output end of the fifth coupler (203) is connected with a first single-mode optical fiber (204), the first single-mode optical fiber (204) is connected with a seventh polarization controller (205), the seventh polarization controller (205) is connected with the input end of a sixth coupler (206), the output end of the sixth coupler (206) is connected with a second optical fiber delay line (209), the second optical fiber delay line (209) is connected with an eighth polarization controller (208), the eighth polarization controller (208) is connected with a third high-birefringence optical fiber (207), the third high-birefringence optical fiber (207) is connected with the other input end of the sixth coupler (206), the other output end of the sixth coupler (206) is connected with the input end of a seventh coupler (210); the other output end of the fifth coupler (203) is connected with a second single-mode optical fiber (211), the second single-mode optical fiber (211) is connected with a third optical fiber delay line (212), the third optical fiber delay line (212) is connected with a ninth polarization controller (213), the ninth polarization controller (213) is connected with the other input end of the seventh coupler (210), and finally the light pulse is output from the output end of the seventh coupler (210).

4. The system of claim 1, wherein the system is capable of generating high power multi-wavelength optical pulses with a repetition rate of 100 kHz or higher. The shaping optical path module (3) has the following optical path structure: the light pulse is transmitted to a first half-wave plate (301), reflected by a first mirror (302) and a second mirror (303) and then enters a first expansion mirror (304), the light pulse is reflected by a third mirror (305) to a first spatial light modulator (306) after passing through the first expansion mirror (304), and the light beam modulated by the first spatial light modulator (306) passes through a first convex lens (307), a second convex lens (308) and a non-polarization beam splitter (309), wherein one light beam passing through the non-polarization beam splitter (309) is focused by a third convex lens (310) and then incident on a first feedback device (311), and the other light beam passing through the non-polarization beam splitter (309) is focused by a fourth convex lens (312) and then output after passing through a fourth mirror (313).

5. The system of claim 1, wherein the system is capable of generating high power multi-wavelength optical pulses with a repetition rate of 100 kHz or higher. The power amplification module (4) has the following optical path structure: optical pulses are transmitted to a passive optical fiber (402) through a semiconductor saturable absorber mirror (401), a second erbium-doped optical fiber (403) is connected with an input end of a first fiber Bragg grating (404), an output end of the first fiber Bragg grating (404) is connected with a common end of a second wavelength division multiplexer (405), a 980nm end of the second wavelength division multiplexer (405) is connected with a second pump source (406), another common end of the second wavelength division multiplexer (405) is connected with an input end of a third isolator (407), an output end of the third isolator (407) outputs light which passes through a fifth mirror (408), a sixth mirror (409), a fifth convex lens (410), a sixth convex lens (411), an input mirror (412), a first Er: YAP crystal (413), an eighth coupler (414), a first band-pass filter (415), a third polarizer (416), a seventh convex lens (417), a dichroic mirror (418), a third pump source (419) is connected with a 980nm end of a third wavelength division multiplexer (420), optical pulses from the common end of the third wavelength division multiplexer (420) pass through an eighth convex lens (421), a ninth convex lens (422) and the dichroic mirror (418), and after the optical pulses are transmitted out from the dichroic mirror (418), they pass through a second Er: YAP crystal (423) and a second band-pass filter (424) and are then output.

6. The system of claim 1, wherein the system is capable of generating high power multi-wavelength optical pulses with a repetition rate of 100 kHz or higher. The pulse compression module (5) has the following optical path structure: the light pulse is incident to the second polarization beam splitter (502) through the first polarization beam splitter (501), part of the light pulse passing through the second polarization beam splitter (502) is transmitted to the seventh mirror (503), the light pulse is reflected by the seventh mirror (503) and then is reflected by the eighth mirror (504), the ninth mirror (505), and the tenth mirror (506) in sequence, the light pulse reflected by the tenth mirror (506) is incident to the first grating (512), the first grating (512) reflects the light pulse to the second grating (513), the second grating (513) reflects the light pulse to the eleventh mirror (514), the light pulse reaches the eleventh mirror (514) and is reflected back to the first grating (512) along the input route, the first grating (512) transmits the light pulse to the twelfth mirror (515), the light pulse is reflected by the twelfth mirror (515) to the thirteenth mirror (517), and then is incident to the tenth convex lens (535), another part of the light pulse output from the second polarization beam splitter (502) is transmitted to the fourteenth mirror (507), the light pulse is reflected by the fourteenth mirror (507) and then is reflected by the fifteenth mirror (508), the sixteenth mirror (509), the seventeenth mirror (510), and the eighteenth mirror (511) in sequence, the light pulse reflected by the eighteenth mirror (511) and the light pulse reflected by the tenth mirror (506) enter the first grating (512) in parallel, the light pulse incident to the first grating (512) from the tenth mirror (506) is transmitted to the first grating (512), the second grating (513), the eleventh mirror (514) in sequence and returns to the first grating (512) along the input route, the light pulse is transmitted by the first grating (512) to the twelfth mirror (515), the light pulse is reflected by the twelfth mirror (515) to the nineteenth mirror (516), and then is incident to the tenth convex lens (535), the light pulse is transmitted by another output end of the first polarization beam splitter (501) to the twentieth mirror (518), is transmitted to the third polarization beam splitter (519) through the twentieth mirror (518), part of the light pulse passing through the third polarization beam splitter (519) is transmitted to the twenty-first mirror (520), the light pulse is reflected by the twenty-first mirror (520) and then is reflected by the twenty-second mirror (521), the twenty-third mirror (522), and the twenty-fourth mirror (523) in sequence, the light pulse reflected by the twenty-fourth mirror (523) is incident to the third grating (529), the third grating (529) reflects the light pulse to the fourth grating (530), the fourth grating (530) reflects the light pulse to the twenty-fifth mirror (531), the light pulse reaches the twenty-fifth mirror (531) and is reflected back to the third grating (529) along the input route,The third grating (529) transmits the light pulses to the twenty-sixth mirror (532), the light pulses are reflected by the twenty-sixth mirror (532) to the twenty-seventh mirror (534), and are reflected by the twenty-seventh mirror (534) to the tenth convex lens (535). Another part of the light pulses output from the third polarization beam splitter (519) is transmitted to the twenty-eighth mirror (524), and the light pulses are reflected by the twenty-eighth mirror (524) and then pass through the twenty-ninth mirror (525), the thirtieth mirror (526), the thirty-first mirror (527), and the thirty-second mirror (528) in sequence. The light pulses reflected by the thirty-second mirror (528) enter the third grating (529) in parallel with the light pulses reflected by the twenty-fourth mirror (523). The light pulses enter the third grating (529) from the twenty-fourth mirror (523) along the incident path as described above, pass through the third grating (529), the fourth grating (530), and the twenty-fifth mirror (531) in sequence, and return to the third grating (529) along the input path. The light pulses are transmitted by the third grating (529) to the twenty-sixth mirror (532), reflected by the twenty-sixth mirror (532) to the thirty-third mirror (533), reflected by the thirty-third mirror (533) to the tenth convex lens (535), and enter the tenth convex lens (535) in parallel after passing through the nineteenth mirror (516), the thirteenth mirror (517), the twenty-seventh mirror (534), and the thirty-third mirror (533) respectively. The light pulses are focused by the tenth convex lens (535) and then fused. The fused light pulses are reflected by the thirty-fourth mirror (536) to the thirty-fifth mirror (537), transmitted by the thirty-fifth mirror (537) to the second half-wave plate (538), reflected by the thirty-sixth mirror (539) to the second spatial light modulator (540) after passing through the second half-wave plate (538), and then pass through the eleventh convex lens (541), the twelfth convex lens (542), and the thirteenth convex lens (543) to be focused and incident on the second feedback device (544). The light pulses are transmitted by the second feedback device (544) to the thirty-seventh mirror (545), the thirty-eighth mirror (546), and the third half-wave plate (547), incident on the fourth polarization beam splitter (548) after passing through the third half-wave plate (547), output from the output end parallel to the incident direction of the fourth polarization beam splitter (548), transmitted to the thirty-ninth mirror (549), reflected by the thirty-ninth mirror (549) to the fortieth mirror (550), reflected by the fortieth mirror (550) to the first concave mirror (552), incident on the second concave mirror (554) through the LBO crystal (553) after passing through the first concave mirror (552), incident on the forty-first mirror (555) after passing through the second concave mirror (554),After being reflected by the forty-first mirror (555) to the third concave mirror (556), the light pulse output by the third concave mirror (556) passes through the BBO crystal (557) and is incident to the fourth concave mirror (558), and the light pulse is reflected by the fourth concave mirror (558) to the forty-second mirror (551), and then is incident to the first concave mirror (552). The light pulse passes through the first concave mirror (552) again according to the above-mentioned route, and then passes through the first concave mirror (552), the LBO crystal (553), the second concave mirror (554), the forty-first mirror (555), the third concave mirror (556), the BBO crystal (557), and the fourth concave mirror (558). After multiple reflections, the light pulse returns to the fourth concave mirror (558), and the light pulse is transmitted and output by the fourth concave mirror (558) to the fourteenth convex lens (559), and the light pulse is output.

Images