Multi-wavelength visible light source that enhances spectral performance using hybrid nonlinear processes

Abstract

To address the limitation of existing tunable visible light sources in achieving customizable visible light output, this invention provides a multi-wavelength visible light source that enhances spectral performance through a hybrid nonlinear process. The use of a chirped polarized periodic lithium niobate waveguide significantly relaxes the quasi-phase matching requirements. Furthermore, by combining the chirped polarized periodic lithium niobate waveguide with an acousto-optic tunable filter, the limited number of filter channels can be overcome using hybrid nonlinear processes (including frequency doubling and sum-frequency generation), greatly expanding the number of output wavelengths. Simultaneously, the output spectrum exhibits adjustable wavelength count, intensity, spacing, and linewidth, achieving multi-wavelength, flexibly tunable visible light output.

Description

Technical Field

[0001] This invention mainly relates to the field of fiber laser technology, and in particular to a multi-wavelength visible light source that utilizes a hybrid nonlinear process to improve spectral performance. Background Technology

[0002] Fiber lasers with flexibly tunable spectra have wide applications in wavelength division multiplexing (WDM) communication, laser biomedicine, hyperspectral imaging, photoacoustic spectroscopy, and laser pumping. In particular, light sources with flexibly tunable visible light spectra have applications in fiber optic sensing, medical imaging, and multispectral lidar.

[0003] The spectrum can be flexibly controlled, including achieving multi-wavelength output, adjustable number of wavelengths, independent tuning of the linewidth and intensity of each wavelength, and tunable wavelength spacing. Researchers utilize nonlinear effects, such as four-wave mixing, cascaded stimulated Brillouin scattering, or filter structures, such as Lyot filters, Sagnac rings, MZ interferometers, and FP interferometers, to achieve multi-wavelength output. However, limited by the gain band of rare-earth ions in the gain fiber, lasers typically operate only in the infrared band. Furthermore, due to limitations in filtering principles, it is difficult to simultaneously achieve multi-dimensional spectral control, thus hindering applications requiring specific spectral shape and light source coherence, such as wavelength division multiplexing communication and partially coherent optical imaging. In contrast, in acousto-optic tunable filters, parameters such as the frequency, intensity, and number of channels of the radio frequency signal can be adjusted to achieve independent control of the number of output wavelengths, wavelength spacing, and intensity.

[0004] One mature technology for achieving visible light output is nonlinear frequency conversion. However, due to the strict requirements for quasi-phase matching bandwidth, the wavelength shift and the increase in linewidth will lead to a decrease in output power, making it difficult to achieve spectrally customizable visible light output. Summary of the Invention

[0005] To address the limitation of existing tunable visible light sources in achieving customizable visible light output, this invention provides a multi-wavelength visible light source that enhances spectral performance through a hybrid nonlinear process. The use of a chirped polarized periodic lithium niobate waveguide significantly relaxes the quasi-phase matching requirements. Furthermore, by combining the chirped polarized periodic lithium niobate waveguide with an acousto-optic tunable filter, the limited number of filter channels can be overcome using hybrid nonlinear processes (including frequency doubling and sum-frequency generation), greatly expanding the number of output wavelengths. Simultaneously, the output spectrum exhibits adjustable wavelength count, intensity, spacing, and linewidth, achieving multi-wavelength, flexibly tunable visible light output.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a multi-wavelength visible light source that improves spectral performance using a hybrid nonlinear process, comprising a spectrally customizable seed source, an optical fiber amplifier, a chirped polarized periodic lithium niobate waveguide, a wavelength division multiplexer, a fundamental frequency output terminal, and a visible light output terminal;

[0008] A spectrally customizable seed source outputs seed light of the desired spectrum; the spectrally customizable seed source connects to the input of an optical fiber amplifier, the output of the optical fiber amplifier connects to the input of a chirped polarized periodic lithium niobate waveguide, the output of the chirped polarized periodic lithium niobate waveguide connects to the input of a wavelength division multiplexer, one output of the wavelength division multiplexer connects to the fundamental frequency output, and the other output of the wavelength division multiplexer connects to the visible light output.

[0009] In this invention: a spectrally customizable seed source outputs seed light of the desired spectrum; the seed light from the spectrally customizable seed source is injected into an optical fiber amplifier to obtain high-power fundamental frequency light output; the fundamental frequency light output from the optical fiber amplifier is injected into a chirped polarized periodic lithium niobate waveguide, undergoing nonlinear frequency conversion to obtain spectrally customizable multi-wavelength visible light output; wherein the wavelength range corresponding to the polarization period of the chirped polarized periodic lithium niobate waveguide needs to cover the range of the desired spectrum. A wavelength division multiplexer separates the fundamental frequency light and visible light, with the fundamental frequency light output from the fundamental frequency light output terminal and the visible light output from the visible light output terminal.

[0010] Preferably, the spectrally customizable seed source includes a superfluorescent fiber optic source and an acousto-optic tunable filter. The superfluorescent fiber optic source is connected to the input of the acousto-optic tunable filter, and the output of the acousto-optic tunable filter is connected to the input of an fiber optic amplifier. The superfluorescent fiber optic source provides initial seed light, and the transmission spectrum of the initial seed light is customized according to the desired spectrum by the acousto-optic tunable filter, thereby achieving customized output of the spectrum of the superfluorescent seed source. The method includes: first determining the desired spectrum of the superfluorescent seed source, and then setting the number of radio frequency channels and the radio frequency intensity of the acousto-optic tunable filter according to the desired spectrum of the superfluorescent seed source; the initial seed light is passed through the acousto-optic tunable filter to achieve customized output of the spectrum of the superfluorescent seed source.

[0011] Preferably, another implementation of the spectrally customizable seed source includes an acousto-optic tunable filter, a semiconductor laser, an (N+1)×1 fiber pump / signal combiner, a ytterbium-doped fiber, a fiber coupler, and a fiber isolator.

[0012] There are N semiconductor lasers, where N is greater than or equal to 1; an optical fiber coupler is an optical fiber coupler that can split an input beam into two output beams according to a certain splitting ratio.

[0013] The output pigtails of N semiconductor lasers are connected to the N pump arms of an (N+1)×1 fiber pump / signal combiner. The combining end of the fiber pump / signal combiner is connected to the input end of a ytterbium-doped fiber. The output end of the ytterbium-doped fiber is connected to the input end of a fiber coupler. The fiber coupler has two output ends. The first output end of the fiber coupler is connected to an acousto-optic tunable filter. The acousto-optic tunable filter is connected to a fiber isolator and then connected to the signal input arm of the (N+1)×1 fiber pump / signal combiner. The second output end of the fiber coupler is connected to the input end of a fiber amplifier.

[0014] An (N+1)×1 fiber pump / signal combiner, ytterbium-doped fiber, fiber coupler, acousto-optic tunable filter, and fiber isolator are connected to form a ring cavity. The acousto-optic tunable filter provides laser gain feedback in the ring cavity, and the fiber isolator is used to block the reverse traveling wave.

[0015] This invention provides a multi-wavelength visible light source that enhances spectral performance through a hybrid nonlinear process. By combining the spectral tuning capability of a filter with the hybrid nonlinear process in a chirped polarized periodic lithium niobate waveguide, it can significantly expand the number of visible light wavelengths output while maintaining good spectral tuning capability. Compared to ordinary tunable visible light sources in the prior art, this invention achieves the following technical effects:

[0016] Compared to multi-wavelength lasers based on other technologies, this invention uses an acousto-optic tunable filter to achieve more flexible spectral customization, such as adjustable wavelength number, intensity, and spacing.

[0017] This invention utilizes the hybrid nonlinear process of chirped lithium niobate waveguides to greatly expand the number of output wavelengths of the light source, thereby compensating for the limitation of acousto-optic tunable filters in terms of the limited number of output wavelengths. Specifically, when the number of input wavelengths of a chirped polarized periodic lithium niobate waveguide is m, the maximum number of output wavelengths of the chirped polarized periodic lithium niobate waveguide is m + 0.5 * m! / (m - 2)!. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a structural diagram of the light source provided in Embodiment 1 of the present invention;

[0020] Figure 2 This is a structural diagram of the light source provided in Embodiment 2 of the present invention;

[0021] Figure 3 This is a schematic diagram illustrating the principle of Embodiment 1 of the present invention;

[0022] Figure 4 This is a schematic diagram of the principle of Embodiment 2 of the present invention.

[0023] Explanation of icon numbers:

[0024] 1. Superfluorescent fiber optic light source; 2. Acousto-optic tunable filter; 3. Fiber optic amplifier; 4. Chirped polarized periodic lithium niobate waveguide; 5. Wavelength division multiplexer; 6. Fundamental frequency output terminal; 7. Visible light output terminal; 8. Semiconductor laser; 9. (N+1)×1 fiber pump / signal combiner; 10. Ytterbium-doped fiber; 11. Fiber optic coupler; 12. Fiber optic isolator.

[0025] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention provides a multi-wavelength visible light source that utilizes a hybrid nonlinear process to enhance spectral performance. It includes a spectrally customizable seed source, an fiber amplifier 3, a chirped polarized periodic lithium niobate waveguide 4, a wavelength division multiplexer 5, a fundamental frequency output terminal 6, and a visible light output terminal 7. The spectrally customizable seed source outputs seed light of the desired spectrum. The spectrally customizable seed source is connected to the input of the fiber amplifier 3. The output of the fiber amplifier 3 is connected to the input of the chirped polarized periodic lithium niobate waveguide 4. The output of the chirped polarized periodic lithium niobate waveguide 4 is connected to the input of the wavelength division multiplexer 5. One output of the wavelength division multiplexer 5 is connected to the fundamental frequency output terminal 6, and the other output of the wavelength division multiplexer 5 is connected to the visible light output terminal 7.

[0028] A spectrally customizable seed source outputs seed light with the desired spectrum;

[0029] The seed light output from the spectrally customizable seed source is injected into the fiber amplifier 3 to obtain high-power spectrally customizable fundamental frequency light output.

[0030] The fundamental frequency light output from the fiber amplifier 3 is injected into the chirped polarized periodic lithium niobate waveguide 4, resulting in nonlinear frequency conversion (including sum frequency and frequency doubling) to obtain multi-wavelength visible light output with customizable spectrum.

[0031] Wavelength division multiplexer 5 separates the fundamental frequency light from the visible light. The fundamental frequency light is output from the fundamental frequency light output terminal 6, and the visible light is output from the visible light output terminal 7.

[0032] Example 1:

[0033] like Figure 1 As shown, a multi-wavelength visible light source with enhanced spectral performance utilizing a hybrid nonlinear process is provided, comprising a superfluorescent fiber optic source 1, an acousto-optic tunable filter 2, a fiber amplifier 3, a chirped polarized periodic lithium niobate waveguide 4, a wavelength division multiplexer 5, a fundamental frequency output terminal 6, and a visible light output terminal 7. The superfluorescent fiber optic source 1 and the acousto-optic tunable filter 2 constitute the spectrally customizable seed source of this embodiment.

[0034] The superfluorescent fiber optic light source 1 is connected to the input of the acousto-optic tunable filter 2. The output of the acousto-optic tunable filter 2 is connected to the input of the fiber optic amplifier 3. The output of the fiber optic amplifier 3 is connected to the input of the chirped polarized periodic lithium niobate waveguide 4. The output of the chirped polarized periodic lithium niobate waveguide 4 is connected to the input of the wavelength division multiplexer 5. One output of the wavelength division multiplexer 5 is connected to the fundamental frequency optical output 6, and the other output of the wavelength division multiplexer 5 is connected to the visible light output 7.

[0035] The working process of this embodiment:

[0036] The superfluorescent fiber optic source 1 provides initial seed light, and the transmission spectrum of the initial seed light is customized through an acousto-optic tunable filter to achieve customized output of the spectrum of the superfluorescent seed source. This includes: first determining the required spectrum of the superfluorescent seed source, and then setting the number of radio frequency channels and radio frequency intensity of the acousto-optic tunable filter according to the required spectrum of the superfluorescent seed source; the initial seed light achieves customized output of the spectrum of the superfluorescent seed source through the acousto-optic tunable filter.

[0037] Furthermore, the number of radio frequency channels and the radio frequency intensity of the acousto-optic tunable filter are set according to the spectrum of the desired superfluorescent seed source. The method includes:

[0038] Assume the acousto-optic tunable filter has n available radio frequency channels;

[0039] Based on the wavelength m of the spectrum of the required superfluorescent seed source, set the number of radio frequency channels m of the acousto-optic tunable filter, where m is less than or equal to n;

[0040] Based on the m wavelengths in the spectrum of the required superfluorescent seed source and the correspondence between the RF frequency and the output wavelength of the acousto-optic tunable filter, determine the RF frequencies of the m RF channels that are enabled by the acousto-optic tunable filter.

[0041] The output wavelength and RF intensity of each RF channel are determined by using the RF frequency and RF intensity of each RF channel enabled by the acousto-optic tunable filter.

[0042] If a wideband output is required, multiple RF channels with similar RF frequencies are set up so that multiple wavelengths partially overlap, thereby obtaining a linewidth tunable output.

[0043] The seed light output from the acousto-optic tunable filter 2 is injected into the fiber amplifier 3 to obtain a high-power, spectrally customizable fundamental frequency light output.

[0044] The fundamental frequency light output from fiber amplifier 3 is injected into chirped polarized periodic lithium niobate waveguide 4, undergoing nonlinear frequency conversion to obtain multi-wavelength visible light output with customizable spectrum. The principle is as follows: Figure 3 As shown, the mixing and frequency doubling process will result in a frequency of f. i and f j The fundamental frequency light simultaneously generates a frequency of 2f i and 2f j The frequency-doubled light and the frequency f i +f j This allows for the expansion of the number of wavelengths by using sum-frequency light.

[0045] Wavelength division multiplexer 5 separates the fundamental frequency light from the visible light. The fundamental frequency light is output from the fundamental frequency light output terminal 6, and the visible light is output from the visible light output terminal 7.

[0046] Example 2:

[0047] like Figure 2 As shown, a fully fiber-optic customizable multi-wavelength visible laser is provided, comprising an acousto-optic tunable filter 2, a fiber amplifier 3, a chirped polarized periodic lithium niobate waveguide 4, a wavelength division multiplexer 5, a fundamental frequency output terminal 6, a visible light output terminal 7, a semiconductor laser 8, an (N+1)×1 fiber pump / signal combiner 9, a ytterbium-doped fiber 10, a fiber coupler 11, and a fiber isolator 12. There are N semiconductor lasers 8, where N is greater than or equal to 1. The fiber coupler 11 is capable of splitting the input beam into two output beams according to a certain splitting ratio. In practical applications, fiber couplers with different splitting ratios are used according to requirements.

[0048] The output pigtails of N semiconductor lasers 8 are connected to the N pump arms of an (N+1)×1 fiber pump / signal combiner 9. The combining end of the fiber pump / signal combiner 9 is connected to the input end of a ytterbium-doped fiber 10. The output end of the ytterbium-doped fiber 10 is connected to the input end of a fiber coupler 11. The fiber coupler 11 has two output ends. The first output end of the fiber coupler 11 is connected to an acousto-optic tunable filter 2. The acousto-optic tunable filter 2 is connected to a fiber isolator 12 and then connected to the signal input arm of the (N+1)×1 fiber pump / signal combiner 9. The (N+1)×1 fiber pump / signal combiner 9, the ytterbium-doped fiber 10, the fiber coupler 11, the acousto-optic tunable filter 2, and the fiber isolator 12 are connected to form a ring cavity. The acousto-optic tunable filter 2 provides laser gain feedback in the ring cavity. The fiber isolator 12 is used to block the reverse traveling wave.

[0049] The acousto-optic tunable filter 2, semiconductor laser 8, (N+1)×1 fiber pump / signal combiner 9, ytterbium-doped fiber 10, fiber coupler 11 and fiber isolator 12 together constitute a spectrally customizable seed source.

[0050] The lasers output from N semiconductor lasers 8 are coupled into a ytterbium-doped fiber 10 via an (N+1)×1 fiber pump / signal combiner 9, exciting a broadband ASE (amplified spontaneous emission) light. This light is then split by a fiber coupler 11 within the ytterbium-doped fiber 10, with a small portion of the laser beam entering an acousto-optic tunable filter 2 from the first output of the fiber coupler 11. The number of RF channels and the RF intensity of the acousto-optic tunable filter 2 are set according to the desired spectrum, enabling a customizable output of the seed laser spectrum from the seed source. The acousto-optic tunable filter 2 outputs laser light with the desired spectral shape, which then passes through a fiber isolator 12 and is coupled back into the ytterbium-doped fiber 10 via the fiber pump / signal combiner 9. This provides laser gain feedback, further amplifying the laser with the desired spectrum and creating laser oscillation, which is then output from the second output of the fiber coupler 11.

[0051] The second output terminal of the fiber optic coupler 11 is connected to the input terminal of the fiber optic amplifier 3. The output terminal of the fiber optic amplifier 3 is connected to the input terminal of the chirped polarized periodic lithium niobate waveguide 4. The output terminal of the chirped polarized periodic lithium niobate waveguide 4 is connected to the input terminal of the wavelength division multiplexer 5. One output terminal of the wavelength division multiplexer 5 is connected to the fundamental frequency optical output terminal 6, and the other output terminal of the wavelength division multiplexer 5 is connected to the visible light output terminal 7.

[0052] The number of RF channels and RF intensity of the acousto-optic tunable filter 2 are set according to the required spectrum to achieve customizable output of the seed laser spectrum from the seed source. The method includes:

[0053] Assume the acousto-optic tunable filter has n available radio frequency channels;

[0054] Based on the required number of wavelengths m in the spectrum, set the number of radio frequency channels m of the acousto-optic tunable filter, where m is less than or equal to n;

[0055] Based on the required m wavelengths in the spectrum and the correspondence between the RF frequency and the output wavelength of the acousto-optic tunable filter, determine the RF frequencies of the m RF channels that the acousto-optic tunable filter will be enabled.

[0056] The output wavelength and RF intensity of each RF channel are determined by using the RF frequency and RF intensity of each RF channel enabled by the acousto-optic tunable filter.

[0057] The seed light output from the second output end of the fiber coupler 11 is injected into the fiber amplifier 3 to obtain a high-power, spectrally customizable fundamental frequency light output.

[0058] The fundamental frequency light output from fiber amplifier 3 is injected into chirped polarized periodic lithium niobate waveguide 4, undergoing nonlinear frequency conversion to obtain multi-wavelength visible laser output with customizable spectrum. The principle is as follows: Figure 4 As shown, the mixing and frequency doubling process will result in a frequency of f. i and f j The fundamental frequency light simultaneously generates a frequency of 2f i and 2f j The frequency-doubled light and the frequency f i +f j This allows for the expansion of the number of wavelengths by using sum-frequency light.

[0059] Wavelength division multiplexer 5 separates the fundamental frequency light from the visible light. The fundamental frequency light is output from the fundamental frequency light output terminal 6, and the visible light is output from the visible light output terminal 7.

[0060] Matters not covered in this invention are common knowledge.

[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-wavelength visible light source that utilizes a hybrid nonlinear process to enhance spectral performance, characterized in that, This includes a spectrally customizable seed source, fiber amplifier, chirped polarized periodic lithium niobate waveguide, wavelength division multiplexer, fundamental frequency output terminal, and visible light output terminal; The spectrally customizable seed source includes a super-fluorescent fiber optic source and an acousto-optic tunable filter. The super-fluorescent fiber optic source is connected to the input of the acousto-optic tunable filter, and the output of the acousto-optic tunable filter is connected to the input of the fiber optic amplifier. Alternatively, the spectrally customizable seed source may include an acousto-optic tunable filter, a semiconductor laser, an (N+1)×1 fiber pump / signal combiner, ytterbium-doped fiber, fiber coupler, and fiber isolator. There are N semiconductor lasers, where N is greater than or equal to 1. The fiber coupler is a fiber coupler that can split the input beam into two output beams according to a certain splitting ratio. The output pigtails of the N semiconductor lasers are connected to the N pump arms of a (N+1)×1 fiber pump / signal combiner. The combining end of the fiber pump / signal combiner is connected to the input end of a ytterbium-doped fiber. The output end of the ytterbium-doped fiber is connected to the input end of the fiber coupler. The fiber coupler has two output ends. The first output end of the fiber coupler is connected to an acousto-optic tunable filter. The acousto-optic tunable filter is connected to an fiber isolator and then connected to the signal input arm of the (N+1)×1 fiber pump / signal combiner. The second output end of the fiber coupler is connected to the input end of a fiber amplifier. The (N+1)×1 fiber pump / signal combiner, ytterbium-doped fiber, fiber coupler, acousto-optic tunable filter, and fiber isolator are connected to form a ring cavity. The acousto-optic tunable filter provides laser gain feedback in the ring cavity, and the fiber isolator is used to block the reverse traveling wave. A customizable seed source outputs seed light of the desired spectrum; the customizable seed source is connected to the input of an optical fiber amplifier, the output of which is connected to the input of a chirped polarized periodic lithium niobate waveguide; the fundamental frequency light output from the optical fiber amplifier is injected into the chirped polarized periodic lithium niobate waveguide, resulting in mixing and frequency doubling; the output of the chirped polarized periodic lithium niobate waveguide is connected to the input of a wavelength division multiplexer; one output of the wavelength division multiplexer is connected to the fundamental frequency output, and the other output is connected to the visible light output.

2. The multi-wavelength visible light source with enhanced spectral performance utilizing a hybrid nonlinear process as described in claim 1, characterized in that, A spectrally customizable seed source outputs seed light of the desired spectrum; the seed light output from the spectrally customizable seed source is injected into an optical fiber amplifier to obtain high-power fundamental frequency light output; the fundamental frequency light output from the optical fiber amplifier is injected into a chirped polarized periodic lithium niobate waveguide, resulting in nonlinear frequency conversion to obtain spectrally customizable multi-wavelength visible light output; a wavelength division multiplexer separates the fundamental frequency light from the visible light, with the fundamental frequency light output from the fundamental frequency light output end and the visible light output from the visible light output end.

3. The multi-wavelength visible light source with enhanced spectral performance utilizing a hybrid nonlinear process as described in claim 2, characterized in that, The wavelength range corresponding to the polarization period of a chirped polarized periodic lithium niobate waveguide needs to cover the required spectral range.

4. The multi-wavelength visible light source with enhanced spectral performance utilizing a hybrid nonlinear process according to claim 1, 2, or 3, characterized in that, The superfluorescent fiber optic source provides initial seed light, and the transmission spectrum of the initial seed light is customized through an acousto-optic tunable filter to achieve customized output of the spectrum of the superfluorescent seed source. This includes: first determining the required spectrum of the superfluorescent seed source, and then setting the number of RF channels and RF intensity of the acousto-optic tunable filter according to the required spectrum of the superfluorescent seed source; the initial seed light achieves customized output of the spectrum of the superfluorescent seed source through the acousto-optic tunable filter.

5. The multi-wavelength visible light source with enhanced spectral performance utilizing a hybrid nonlinear process according to claim 4, characterized in that, The number of RF channels and RF intensity of the acousto-optic tunable filter are set according to the spectrum of the desired superfluorescent seed source. The method includes: Assume the acousto-optic tunable filter has n available radio frequency channels; Based on the wavelength m of the spectrum of the required superfluorescent seed source, set the number of radio frequency channels m of the acousto-optic tunable filter, where m is less than or equal to n; Based on the m wavelengths in the spectrum of the required superfluorescent seed source and the correspondence between the RF frequency and the output wavelength of the acousto-optic tunable filter, determine the RF frequencies of the m RF channels that are enabled by the acousto-optic tunable filter. The output wavelength and RF intensity of each RF channel are determined by using the RF frequency and RF intensity of each RF channel enabled by the acousto-optic tunable filter.

6. The multi-wavelength visible light source with enhanced spectral performance utilizing a hybrid nonlinear process according to claim 1, 2, or 3, characterized in that, The lasers output from N semiconductor lasers are coupled into a ytterbium-doped fiber via an (N+1)×1 fiber pump / signal combiner, exciting a broadband ASE light. This light is then split by a fiber coupler within the ytterbium-doped fiber, with a small portion of the laser beam entering an acousto-optic tunable filter from the first output of the fiber coupler. The number of RF channels and the RF intensity of the acousto-optic tunable filter are set according to the desired spectrum, enabling customizable output of the seed laser spectrum from the seed source. The laser with the desired spectral shape is output from the acousto-optic tunable filter, then passes through a fiber isolator, and is coupled back into the ytterbium-doped fiber via the fiber pump / signal combiner. This provides laser gain feedback, further enhancing the laser with the desired spectrum and creating laser oscillation, which is then output from the second output of the fiber coupler.

Images