A device for generating a circulating frequency-shifted optical frequency comb based on Brillouin amplification

Abstract

The present invention relates to a device for generating a cyclic frequency-shifted optical frequency comb based on Brillouin amplification. The present invention relates to the field of optoelectronic technology, and includes a continuously tunable pump laser, a first coupler, a cyclic frequency-shifting module, a frequency-shifting module, and a Brillouin amplification cyclic frequency-shifting module. The continuously tunable pump laser is optically connected to the first coupler. The first coupler is optically connected to the cyclic frequency-shifting module and the frequency-shifting module respectively. The Brillouin amplification cyclic frequency-shifting module is optically connected to the cyclic frequency-shifting module and the frequency-shifting module respectively. In this application, a multi-channel Brillouin gain region generated in the Brillouin amplification cyclic frequency-shifting module is used to replace the erbium-doped fiber amplifier in the traditional loop to compensate for the loop loss. By using the characteristics of the narrow bandwidth and low noise of the Brillouin gain region, the signal-to-noise ratio of the optical frequency comb is improved, and the output of a cyclic frequency-shifted optical frequency comb with a high signal-to-noise ratio is realized. The structure of this application is simple and the signal-to-noise ratio of the generated optical frequency comb teeth is relatively high, which is of great significance to the development of precision spectroscopy and optical communication.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic technology, and in particular to a circulating frequency-shifted optical frequency comb generation device based on Brillouin amplification. Background Art

[0002] In the fields of modern science and technology, due to the increasing demand for precise frequency measurement and frequency standards, optical frequency combs have become an indispensable tool in many applications. Optical frequency combs have advantages such as large comb tooth bandwidth and fixed frequency interval. It successfully connects optics and microwaves together and has important applications in the fields of optical communication, lidar, and precision spectroscopy.

[0003] With the development of optical frequency combs, various methods have emerged to generate optical frequency combs, mainly including: optical frequency combs generated based on microresonators, optical frequency combs generated based on electro-optic modulation, and optical frequency combs generated based on mode-locked lasers. The optical frequency combs generated based on microresonators have uneven spectra and require complex locking techniques to stabilize the output spectrum; the comb tooth frequency interval of the optical frequency combs generated based on mode-locked lasers is affected by the cavity length and cannot be tuned; while the optical frequency combs generated based on electro-optic modulators have a simple structure and tunable repetition frequency, but the output spectrum comb tooth bandwidth is relatively narrow. If high-bandwidth spectrum output is desired, a high-power pump source or cascaded electro-optic modulators need to be used, which increases the system complexity. Among all the structures for generating optical frequency combs by electro-optic modulation, the optical frequency combs generated based on the circulating frequency-shift loop have advantages such as flat comb teeth and simple structure. However, due to the influence of the amplified spontaneous emission (ASE) noise of the erbium-doped fiber amplifier (EDFA) in the loop, the signal-to-noise ratio of the generated optical frequency comb teeth is not high.

[0004] Currently, although various methods have been proposed to improve the signal-to-noise ratio of the circulating frequency-shifted optical frequency comb teeth, generally speaking, these methods all obtain high-signal-to-noise ratio teeth by reducing the number of internal cavity circulations. However, the effect of improving the signal-to-noise ratio by reducing the number of internal cavity circulations is not good, because reducing the number of internal cavity circulations means reducing the number of generated comb teeth, and these teeth still have a tendency of signal-to-noise ratio degradation due to the ASE noise of the EDFA, and other negative effects will also occur. Summary of the Invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problem of relatively large spontaneous emission noise in the traditional cyclic frequency shift loop in the prior art and the low signal-to-noise ratio of the generated optical frequency comb teeth. To solve the above technical problem, the present invention provides a cyclic frequency shift optical frequency comb generation device based on Brillouin amplification, which uses a multi-channel Brillouin gain region to replace the erbium-doped fiber amplifier in the traditional cyclic frequency shift loop to achieve loss compensation and efficiently improve the signal-to-noise ratio of the optical frequency comb teeth.

[0006] To achieve the above object, the main technical solutions adopted by the present invention include: a continuously tunable pump laser, which is used to generate a continuous pump optical signal; a first coupler, which is optically connected to the continuously tunable pump laser; the first coupler is used to divide the pump optical signal output by the continuously tunable pump laser into a first optical signal and a second optical signal; a cyclic frequency shift module, which is optically connected to the first coupler; the cyclic frequency shift module is used to receive the first optical signal and perform cyclic frequency shift on the first optical signal to generate an initial optical frequency comb; a frequency shift module, which is optically connected to the first coupler; the frequency shift module is used to receive the second optical signal and perform frequency shift on the second optical signal to obtain a frequency-shifted second optical signal; a Brillouin amplification cyclic frequency shift module, which is optically connected to the frequency shift module and the cyclic frequency shift module respectively; the Brillouin amplification cyclic frequency shift module is used to receive the initial optical frequency comb and the frequency-shifted second optical signal, generate a multi-channel Brillouin gain region by using the optical frequency comb, and generate a final optical frequency comb in the Brillouin amplification cyclic frequency shift module according to the frequency-shifted second optical signal and the multi-channel Brillouin gain region.

[0007] In an embodiment of the present invention, the cyclic frequency shift module includes a second coupler, a first polarization controller, a first in-phase-quadrature modulator, a first radio frequency signal source, a first erbium-doped fiber amplifier, and a band-pass optical filter; the second coupler, the first polarization controller, the first in-phase-quadrature modulator, the first erbium-doped fiber amplifier, and the band-pass optical filter are optically connected in sequence to form a first loop structure; the first radio frequency signal source is electrically connected to the first in-phase-quadrature modulator.

[0008] In an embodiment of the present invention, the second coupler is optically connected to the first coupler.

[0009] In an embodiment of the present invention, a second erbium-doped fiber amplifier is provided between the cyclic frequency shift module and the Brillouin amplification cyclic frequency shift module. The input end of the second erbium-doped fiber amplifier is optically connected to the second coupler, and the output end of the second erbium-doped fiber amplifier is optically connected to the Brillouin amplification cyclic frequency shift module.

[0010] In one embodiment of the present invention, the Brillouin amplification cyclic frequency shift module includes a first circulator, a third coupler, a second polarization controller, a second in-phase quadrature modulator, an optical isolator, a Brillouin gain fiber, and a second radio frequency signal source; the first circulator, the third coupler, the second polarization controller, the second in-phase quadrature modulator, the optical isolator, and the Brillouin gain fiber are optically connected in sequence to form a second loop structure; the second radio frequency signal source is electrically connected to the second in-phase quadrature modulator.

[0011] In one embodiment of the present invention, the first circulator includes a first port, a second port, and a third port; the first port is optically connected to the output end of the second erbium-doped fiber amplifier; the first port is used for inputting the initial optical frequency comb; the second port is optically connected to the Brillouin gain fiber, and the second port is used for transmitting the initial optical frequency comb to the Brillouin gain fiber, wherein the Brillouin gain fiber is used for generating a multi-channel Brillouin gain region; the third port is optically connected to the third coupler.

[0012] In one embodiment of the present invention, the frequency shift module includes a third polarization controller, an electro-optic modulator, a third radio frequency signal source, a second circulator, and a distributed feedback laser; the third polarization controller, the electro-optic modulator, the second circulator, and the distributed feedback laser are optically connected in sequence; wherein, the second circulator includes a first port, a second port, and a third port; the first port is optically connected to the electro-optic modulator, and the second port is optically connected to the distributed feedback laser; the third radio frequency signal source and the electro-optic modulator are electrically connected.

[0013] In one embodiment of the present invention, the third polarization controller is optically connected to the first coupler; wherein, the second optical signal is transmitted to the frequency shift module through the third polarization controller.

[0014] In one embodiment of the present invention, the third port of the second circulator is optically connected to the third coupler; wherein, the frequency-shifted second optical signal is transmitted to the Brillouin amplification cyclic frequency shift module through the third coupler and amplified in power through the multi-channel Brillouin gain region.

[0015] In one embodiment of the present invention, the Brillouin amplification cyclic frequency shift module is electrically connected to a spectrometer, and the spectrometer is used for visualizing the final optical frequency comb.

[0016] The above technical solutions of the present invention have the following beneficial effects compared with the prior art:

[0017] The Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device described in the present invention generates multi-channel Brillouin gain regions through a Brillouin gain fiber, and uses the multi-channel Brillouin gain regions to replace the gain regions in the erbium-doped fiber in the traditional cyclic frequency-shift loop to achieve loss compensation. Since the Brillouin gain region has the characteristics of narrow gain bandwidth and large gain, replacing the EDFA in the traditional loop with a multi-channel Brillouin gain region can effectively improve the signal-to-noise ratio of the comb teeth, solving the problem that the overall signal-to-noise ratio of the output optical frequency comb is relatively low due to the influence of the spontaneous emission noise of the erbium-doped fiber amplifier, thereby outputting a cyclic frequency-shifted optical frequency comb with a high signal-to-noise ratio; the structure of this application is simple and easy to implement, can efficiently improve the signal-to-noise ratio of the optical frequency comb, and is conducive to the development of optical communication and precision spectroscopy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the content of the present invention easier to be clearly understood, the following further describes the present invention in detail according to the specific embodiments of the present invention in conjunction with the drawings, where

[0019] Figure 1 is a schematic diagram of the overall structure of the Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device provided by a preferred embodiment of the present invention;

[0020] Figure 2 is Figure 1 the spectrogram of the optical signal output after the first optical signal of the Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device is modulated by the first in-phase-quadrature modulator;

[0021] Figure 3 is Figure 1 the spectrogram of the initial optical frequency comb of the Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device;

[0022] Figure 4 is Figure 1 the spectrogram of the second optical signal after frequency shift of the Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device;

[0023] Figure 5 is Figure 1 the spectrogram of the final optical frequency comb of the Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device.

[0024] Description of the reference numerals in the drawings: 1. Continuously tunable pump laser; 2. First coupler; 3. Second coupler; 4. First polarization controller; 5. First in-phase quadrature modulator; 6. First radio frequency signal source; 7. First erbium-doped fiber amplifier; 8. Band-pass optical filter; 9. Second erbium-doped fiber amplifier; 10. First circulator; 101. First port; 102. Second port; 103. Third port; 11. Brillouin gain fiber; 12. Optical isolator; 13. Frequency shift module; 14. Third coupler; 15. Spectrometer; 16. Second polarization controller; 17. Second in-phase quadrature modulator; 18. Second radio frequency signal source; 19. Second optical signal after frequency shift; 20. First optical signal; 21. Second optical signal. Detailed implementation manners

[0025] The present invention will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments cited shall not be construed as limiting the present invention.

[0026] Referring to Figure 1 As shown, a preferred embodiment of the present invention provides a device for generating a cyclic frequency-shifted optical frequency comb based on Brillouin amplification, including a continuously tunable pump laser 1, a first coupler 2, a cyclic frequency shift module, a frequency shift module 13, and a Brillouin amplification cyclic frequency shift module; wherein, the continuously tunable pump laser 1 is optically connected to the first coupler 2, the first coupler 2 is respectively optically connected to the cyclic frequency shift module and the frequency shift module 13, and the Brillouin amplification cyclic frequency shift module is respectively optically connected to the cyclic frequency shift module and the frequency shift module 13.

[0027] The cyclic frequency shift module includes a second coupler 3, a first polarization controller 4, a first in-phase quadrature modulator 5, a first radio frequency signal source 6, a first erbium-doped fiber amplifier 7, and a band-pass optical filter 8; the second coupler 3, the first polarization controller 4, the first in-phase quadrature modulator 5, the first erbium-doped fiber amplifier 7, and the band-pass optical filter 8 are optically connected in sequence to form a loop structure, which is used as the first loop structure; the first radio frequency signal source 6 is electrically connected to the first in-phase quadrature modulator 5; wherein, the input end of the first in-phase quadrature modulator 5 is optically connected to the first polarization controller 4, the input end of the first erbium-doped fiber amplifier 7 is optically connected to the output end of the first in-phase quadrature modulator 5, and the output end of the first erbium-doped fiber amplifier 7 is optically connected to the band-pass optical filter 8; and the cyclic frequency shift module is optically connected to the first coupler 2 through the second coupler 3 to realize connection with the first coupler 2.

[0028] Specifically, the continuously tunable pump laser 1 generates a continuous pump optical signal, which is split into two optical signals after passing through the first coupler 2, namely the first optical signal 20 and the second optical signal 21. In this application, the cyclic frequency shift module adopts the design of a traditional cyclic frequency shift loop. After the first optical signal 20 enters the cyclic frequency shift module through the second coupler 3 for processing, a cyclic frequency shift optical frequency comb is generated as the initial optical frequency comb. Since the gain bandwidth of the first erbium-doped fiber amplifier 7 in the cyclic frequency shift module is large and it is greatly affected by spontaneous emission noise, the overall signal-to-noise ratio of the initial optical frequency comb is relatively low.

[0029] The Brillouin amplification cyclic frequency shift module includes a first circulator 10, a third coupler 14, a second polarization controller 16, a second in-phase - quadrature modulator 17, an optical isolator 12, a Brillouin gain fiber 11 (Brillouin Gain Fiber, BGF), and a second radio frequency signal source 18. The first circulator 10, the third coupler 14, the second polarization controller 16, the second in-phase - quadrature modulator 17, the optical isolator 12, and the Brillouin gain fiber 11 are optically connected in sequence and form a loop structure as the second loop structure. The second radio frequency signal source 18 is electrically connected to the second in-phase - quadrature modulator 17. Among them, the input end of the second in-phase - quadrature modulator 17 is optically connected to the second polarization controller 16, and the output end of the second in-phase - quadrature modulator 17 is optically connected to the optical isolator 12.

[0030] A second erbium-doped fiber amplifier 9 is arranged between the cyclic frequency shift module and the Brillouin amplification cyclic frequency shift module. The input end of the second erbium-doped fiber amplifier 9 is optically connected to the cyclic frequency shift module, and the output end of the second erbium-doped fiber amplifier 9 is optically connected to the Brillouin amplification cyclic frequency shift module. Specifically, the input end of the second erbium-doped fiber amplifier 9 is optically connected to the second coupler 3, and the output end of the second erbium-doped fiber amplifier 9 is optically connected to the first circulator 10. The first circulator 10 has three ports, namely a first port 101, a second port 102, and a third port 103. The first port 101 is optically connected to the output end of the second erbium-doped fiber amplifier 9. The second port 102 is optically connected to the Brillouin gain fiber 11, and the third port 103 is optically connected to the third coupler 14.

[0031] This application uses a multi-channel Brillouin gain region to replace the erbium-doped fiber amplifier in the traditional cyclic frequency shift loop to achieve loss compensation. Specifically, the initial optical frequency comb serves as a multi-wavelength Brillouin pump source. After being amplified by the second erbium-doped fiber amplifier 9, it is injected into the first port 101 of the first circulator 10 and transmitted to the Brillouin gain fiber 11 through the second port 102. The Brillouin gain fiber 11 is used to generate a multi-channel Brillouin gain region.

[0032] The frequency shift module 13 includes a third polarization controller, an electro-optic modulator, a third radio frequency signal source, a second circulator, and a distributed feedback laser; the third polarization controller, the electro-optic modulator, the second circulator, and the distributed feedback laser are optically connected in sequence. Among them, the second circulator includes a first port, a second port, and a third port; the first port is optically connected to the electro-optic modulator, and the second port is optically connected to the distributed feedback laser; the third radio frequency signal source is electrically connected to the electro-optic modulator; and the third polarization controller in the frequency shift module 13 is optically connected to the first coupler 2, and the third port of the second circulator is optically connected to the third coupler 14 in the Brillouin amplification loop frequency shift module.

[0033] Since the central gain effect of the multi-channel Brillouin gain region is the largest and the spontaneous emission noise is the smallest, it is necessary to perform a frequency shift operation on the second optical signal 21 so that the frequency-shifted second optical signal is aligned with the exact center of the first Brillouin gain channel in the multi-channel Brillouin gain region to achieve the maximum amplification power effect and maximize the signal-to-noise ratio; specifically, the +1 order sideband generated by modulating the second optical signal 21 through the electro-optic modulator is injected into the distributed feedback laser (DFB). Due to the injection locking effect, the DFB signal light output from the second circulator will inherit the characteristics of the injected sideband light, thereby realizing the optical movement of the second optical signal 21 to the first gain maximum of the multi-channel Brillouin gain region. In particular, the final optical frequency comb teeth generated in each cycle in the Brillouin amplification loop frequency shift module are moved to the maximum value of the corresponding Brillouin gain region. At this time, the optical signal in the Brillouin amplification loop frequency shift module changes from counterclockwise transmission to clockwise transmission in the second loop structure, and the optical isolator 12 is used to isolate the counterclockwise incoming optical signal to achieve unidirectional transmission in the second loop structure.

[0034] To better observe the final optical frequency comb, a spectrometer 15 is provided in this application. The spectrometer 15 is connected to the third coupler 14. After the final optical frequency comb generated in each cycle passes through the third coupler 14, it is divided into two paths. One path is visually displayed by the spectrometer 15, and the other path continues for the next cycle; since the continuous tunable pump laser 1 generates continuous pump light, a series of optical frequency comb spectrograms will be displayed on the spectrometer 15.

[0035] In specific operations, the continuously tunable pump laser 1 generates continuous pump light. When the continuous pump light passes through the first coupler 2, it is divided into two paths. The first optical signal 20 enters the cyclic frequency shift module and is sequentially injected into the first in-phase - quadrature modulator 5 through the second coupler 3 and the first polarization controller 4, and is subjected to single-sideband modulation in combination with the first radio frequency signal source 6. The first optical signal 20 after single-sideband modulation is injected into the first erbium-doped fiber amplifier 7 for power amplification to compensate for the loop loss, then passes through the bandpass optical filter 8 to control the output bandwidth of the initial optical frequency comb teeth, and finally the output optical signal returns to the first coupler 2 again. A part of the optical signal that returns to the first coupler 2 continues to circulate in the cavity, and so on, ultimately generating a series of equally spaced optical frequency comb teeth. The initial optical frequency comb, as a multi-wavelength Brillouin pump source, is amplified by the second erbium-doped fiber amplifier 9 and injected into the second port 102 of the first circulator 10 through the first port 101 of the first circulator 10, and is transmitted to the Brillouin gain fiber 11 for generating a multi-channel Brillouin gain region.

[0036] The second optical signal 21 passes through the frequency shift module 13 for frequency shift to ensure that the second optical signal after frequency shift is aligned with the exact center of the first Brillouin gain region of the multi-channel Brillouin gain region, thereby minimizing noise and improving the signal-to-noise ratio to the greatest extent.

[0037] The second optical signal after frequency shift, as the pump light of the Brillouin amplification cyclic frequency shift module, is injected into the loop in the Brillouin amplification cyclic frequency shift module through the third coupler 14 and is aligned with the maximum value of the multi-channel Brillouin gain region. Thereafter, each comb tooth circulating in the loop of the Brillouin amplification cyclic frequency shift module can move to the corresponding Brillouin gain maximum for amplification, thereby achieving the purpose of improving the signal-to-noise ratio of the cyclic frequency shift optical frequency comb, and ultimately generating a high-signal-to-noise cyclic frequency shift optical frequency comb as the final optical frequency comb. The spectral result of the final optical frequency comb is displayed in the spectrometer 15 for easy observation.

[0038] In this embodiment, the operating wavelength of the pump optical signal generated by the continuously tunable pump laser 1 is set to 1551.3 nm, and the linewidth is set to be less than 100 KHz. In this embodiment, an auxiliary optical scanning spectroscopy technique is used to characterize the Brillouin frequency shift corresponding to each comb tooth of the 16 GHz multi-wavelength Brillouin pump source. The Brillouin frequency shift corresponding to the first comb tooth is 10.782 GHz, and the Brillouin frequency shift corresponding to the fifth comb tooth is 10.777 GHz. The length of the Brillouin gain fiber 11 used is 10 km, and the EDFA for pumping the BGF is set to 25 dBm. The radio frequency value of the second radio frequency signal source 18 in the Brillouin amplification cyclic frequency shift module is set to 15.9992 GHz. After setting the device described in this application according to the above parameters, turn on the continuously tunable pump laser 1, set the signal value of the first radio frequency signal source 6 to 16 GHz, and adjust the modulation voltage of the first in-phase-quadrature modulator 5 to achieve single-sideband signal output as Figure 2 shown, with the sideband suppression ratio reaching 25 dB. After turning on the first erbium-doped fiber amplifier 7, a cyclic frequency shift optical frequency comb output is achieved. By adjusting the polarization state of the first polarization controller 4, a flat initial optical frequency comb output is achieved as Figure 3 shown. Figure 3 shows an optical frequency comb with 15 comb teeth and a signal-to-noise ratio of 12 dB.

[0039] Set the frequency shift value of the frequency shift module 13 to 10.782 GHz. The spectrum of the second optical signal after frequency shift is the curve marked 19 in Figure 4 .

[0040] Use the second optical signal after frequency shift as the pump light for the Brillouin amplification cyclic frequency shift module to generate a cyclic frequency shift optical frequency comb with a high signal-to-noise ratio as Figure 5 shown. Figure 5 Displays the spectrum of a cyclic frequency shift optical frequency comb with 12 comb teeth and a signal-to-noise ratio of 30 dB, and the comb flatness is good.

[0041] Finally, display the output spectrum in the spectrometer 15, with a resolution of 0.03 nm.

[0042] In this application, a traditional cyclic frequency shift loop in a cyclic frequency shift module is used to generate a flat and equally spaced initial optical frequency comb. The initial optical frequency comb will serve as a multi-wavelength Brillouin pump source. After being amplified by the second erbium-doped fiber amplifier 9, it is injected into the Brillouin gain fiber 11 optically connected to the second port 102 through the first port 101 of the first circulator 10 (Circulator) to generate a multi-channel Brillouin gain region. The frequency shift module 13 frequency-shifts the pump light generated by the continuously tunable pump laser 1 and uses it as the pump light for the Brillouin amplification cyclic frequency shift module. The multi-channel Brillouin gain region generated by the Brillouin gain fiber 11 is used to replace the erbium-doped fiber amplifier in the traditional cyclic frequency shift loop to compensate for the loss of the cyclic frequency shift loop. Since the Brillouin gain region has the advantages of small bandwidth, low phase noise, and large gain, the optical frequency comb output by the Brillouin amplification cyclic frequency shift module has the characteristic of high signal-to-noise ratio. This application can realize the output of a cyclic frequency shift optical frequency comb with high signal-to-noise ratio by using the Brillouin amplification cyclic frequency shift loop, which is of great significance to the development of precision spectroscopy and optical communication.

[0043] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention should also include these modifications and variations.

[0044] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A cyclic frequency-shifted optical frequency comb generation device based on Brillouin amplification, characterized in that Comprising: A continuously tunable pump laser for generating a continuous pump optical signal; A first coupler optically connected to the continuously tunable pump laser; the first coupler is used to divide the pump optical signal output by the continuously tunable pump laser into a first optical signal and a second optical signal; A cyclic frequency shift module optically connected to the first coupler; the cyclic frequency shift module is used to receive the first optical signal and perform cyclic frequency shift on the first optical signal to generate an initial optical frequency comb; A frequency shift module optically connected to the first coupler; the frequency shift module is used to receive the second optical signal and perform frequency shift on the second optical signal to obtain a frequency-shifted second optical signal; A Brillouin amplification cyclic frequency shift module optically connected to the frequency shift module and the cyclic frequency shift module respectively; the Brillouin amplification cyclic frequency shift module is used to receive the optical frequency comb and the frequency-shifted second optical signal, generate a multi-channel Brillouin gain region by using the initial optical frequency comb, and generate a final optical frequency comb in the Brillouin amplification cyclic frequency shift module according to the frequency-shifted second optical signal and the multi-channel Brillouin gain region; Wherein, the Brillouin amplification cyclic frequency shift module includes a first circulator and a Brillouin gain fiber, and a second erbium-doped fiber amplifier is arranged between the cyclic frequency shift module and the Brillouin amplification cyclic frequency shift module; The initial optical frequency comb serves as a multi-wavelength Brillouin pump source, after being amplified by the second erbium-doped fiber amplifier, it is injected into the first port of the first circulator and transmitted to the Brillouin gain fiber through the second port, and the Brillouin gain fiber is used to generate a multi-channel Brillouin gain region.

2. The device for generating a cyclic frequency shift optical frequency comb based on Brillouin amplification according to claim 1, wherein: The cyclic frequency shift module includes a second coupler, a first polarization controller, a first in-phase-quadrature modulator, a first radio frequency signal source, a first erbium-doped fiber amplifier, and a band-pass optical filter; The second coupler, the first polarization controller, the first in-phase-quadrature modulator, the first erbium-doped fiber amplifier, and the band-pass optical filter are optically connected in sequence and form a first loop structure; The first radio frequency signal source is electrically connected to the first in-phase-quadrature modulator.

3. The device for generating a cyclic frequency shift optical frequency comb based on Brillouin amplification according to claim 2, wherein: The second coupler is optically connected to the first coupler.

4. The device for generating a cyclic frequency shift optical frequency comb based on Brillouin amplification according to claim 2, wherein: The input end of the second erbium-doped fiber amplifier is optically connected to the second coupler, and the output end of the second erbium-doped fiber amplifier is optically connected to the Brillouin amplification cyclic frequency shift module.

5. The device for generating a cyclic frequency shift optical frequency comb based on Brillouin amplification according to claim 4, wherein: The Brillouin amplification cyclic frequency shift module includes a third coupler, a second polarization controller, a second in-phase-quadrature modulator, an optical isolator, and a second radio frequency signal source; The first circulator, the third coupler, the second polarization controller, the second in-phase quadrature modulator, the optical isolator, and the Brillouin gain fiber are optically connected in sequence to form a second loop structure; The second radio frequency signal source is electrically connected to the second in-phase quadrature modulator.

6. The Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device according to claim 5, wherein: The first circulator includes a first port, a second port, and a third port; The first port is optically connected to the output end of the second erbium-doped fiber amplifier; the first port is used for inputting the initial optical frequency comb; The second port is optically connected to the Brillouin gain fiber, and the second port is used for transmitting the initial optical frequency comb to the Brillouin gain fiber, wherein the Brillouin gain fiber is used for generating a multi-channel Brillouin gain region; The third port is optically connected to the third coupler.

7. The Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device according to claim 5, wherein: The frequency-shifting module includes a third polarization controller, an electro-optic modulator, a third radio frequency signal source, a second circulator, and a distributed feedback laser; The third polarization controller, the electro-optic modulator, the second circulator, and the distributed feedback laser are optically connected in sequence; wherein the second circulator includes a one-port, a two-port, and a three-port; the one-port is optically connected to the electro-optic modulator, and the two-port is optically connected to the distributed feedback laser; The third radio frequency signal source and the electro-optic modulator are electrically connected.

8. The Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device according to claim 7, wherein: The third polarization controller is optically connected to the first coupler; wherein the second optical signal is transmitted to the frequency-shifting module through the third polarization controller.

9. The Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device according to claim 7, wherein: The three-port of the second circulator is optically connected to the third coupler; wherein the frequency-shifted second optical signal is transmitted to the Brillouin amplification cyclic frequency-shifting module through the third coupler and the power is amplified by the multi-channel Brillouin gain region.

10. The Brillouin amplification-based cyclic frequency-shifted optical frequency comb generation device according to claim 1, wherein: The Brillouin amplification cyclic frequency-shifting module is electrically connected to a spectrometer, and the spectrometer is used for visualizing the final optical frequency comb.

Images