Super-continuum spectrum light source device

Abstract

The utility model discloses a super-continuum spectrum light source device which comprises an LD pumping source, an optical fiber beam combiner, a high-reflection grating, a first ytterbium-doped optical fiber, a low-reflection grating, a second ytterbium-doped optical fiber, an output optical fiber and an output end cap. The number of the LD pumping sources is multiple, all the LD pumping sources are connected with the input end of the optical fiber beam combiner, the output end of the optical fiber beam combiner is connected with the output end cap through the high-reflection grating, the first ytterbium-doped optical fiber, the low-reflection grating, the second ytterbium-doped optical fiber and the output optical fiber in sequence, and the high-reflection grating, the first ytterbium-doped optical fiber and the low-reflection grating form a resonant cavity. The length of the first ytterbium-doped optical fiber is 0.2-10m, and the length of the second ytterbium-doped optical fiber is 5-100m. The super-continuum spectrum light source device has the advantages of being simple in structure, low in manufacturing cost, good in output stability, high in light-to-light conversion efficiency and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical fiber lasers, and particularly relates to a supercontinuum light source device. Background Art

[0002] A supercontinuum light source is a pulsed laser light source with a wider spectral range than a tunable laser. It is widely used in the fields of optical fiber parameter or optical frequency measurement, optical pulse compression, ultra-high-speed communication, biomedicine and passive device detection.

[0003] At present, there are two main ways to generate supercontinuum light sources: one is to use nonlinear fiber amplifiers, but the threshold for generating supercontinuum is relatively large and the spectral flatness is relatively poor; the other is to use pulsed or continuous fiber lasers to pump photonic crystal fibers, but the system structure required for this method is relatively complex, and high-peak power or high-average power fiber lasers are expensive, and the length of the photonic crystal fiber used is also relatively long, resulting in a high cost for generating supercontinuum light sources. Utility Model Content

[0004] In view of the above problems, the utility model discloses a supercontinuum light source device to overcome the above problems or at least partially solve the above problems.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a supercontinuum light source device, comprising an LD pump source, an optical fiber combiner, a high-reflection grating, a first ytterbium-doped optical fiber, a low-reflection grating, a second ytterbium-doped optical fiber, an output optical fiber and an output end cap;

[0007] The number of the LD pump sources is multiple, each of the LD pump sources is connected to the input end of the fiber combiner, the output end of the fiber combiner is sequentially connected through the high-reflection grating, the first ytterbium-doped fiber, the low-reflection grating, the second ytterbium-doped fiber, the output fiber and the output end cap, and the high-reflection grating, the first ytterbium-doped fiber and the low-reflection grating constitute a resonant cavity;

[0008] The length of the first ytterbium-doped optical fiber is 0.2 m to 10 m, and the length of the second ytterbium-doped optical fiber is 5 m to 100 m.

[0009] Further, a third ytterbium-doped optical fiber is included;

[0010] The third ytterbium-doped optical fiber is disposed between the second ytterbium-doped optical fiber and the output optical fiber.

[0011] Furthermore, the reflectivity of the high-reflection grating is 50% to 99.9%.

[0012] Furthermore, the reflectivity of the low-reflection grating is 5% to 50%.

[0013] Furthermore, the total power of each of the LD pump sources is 10W to 600W.

[0014] Furthermore, the core diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 5 μm to 35 μm, and the cladding diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 100 μm to 500 μm.

[0015] Further, it also includes a red laser;

[0016] The red light laser is connected to the input end of the optical fiber combiner.

[0017] Further, a cladding light filter is included;

[0018] The cladding light filter is arranged between the second ytterbium-doped optical fiber and the output optical fiber.

[0019] Furthermore, the fiber combiner, the high-reflection grating, the first ytterbium-doped fiber and the low-reflection grating are fused in sequence, and the second ytterbium-doped fiber and the cladding light filter are fused.

[0020] The advantages and beneficial effects of the utility model are:

[0021] In the supercontinuum light source device of the utility model, the pump light generated by the LD pump source is input into the first shorter ytterbium-doped optical fiber to generate a pulsed laser, and then the power is amplified and the spectrum is broadened through the second ytterbium-doped optical fiber to achieve the output of the supercontinuum light source. The supercontinuum light source device has the advantages of simple structure, low manufacturing cost, good output stability and high light-to-light conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limiting of the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0023] Figure 1 This is a schematic structural diagram of a supercontinuum light source device in one embodiment of the utility model;

[0024] Figure 2 This is a schematic structural diagram of a supercontinuum light source device in another embodiment of the present invention;

[0025] Figure 3This is a spectrum diagram output by a supercontinuum light source device in an embodiment of the utility model at an output power of 70W;

[0026] Figure 4 This is a diagram showing the relationship between laser pump power and laser output power in one embodiment of the present utility model.

[0027] In the figure: 1. LD pump source; 2. Fiber combiner; 3. High reflection grating; 4. First ytterbium-doped fiber; 5. Low reflection grating; 6. Second ytterbium-doped fiber; 7. Output fiber; 8. Red light laser; 9. Cladding light filter; 10. Output end cap; 11. Third ytterbium-doped fiber. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in combination with the specific embodiments of the utility model and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0030] In one embodiment of the present invention, a supercontinuum light source device is provided, such as Figure 1 As shown, the supercontinuum light source device includes an LD pump source 1, a fiber combiner 2, a high-reflection grating 3, a first ytterbium-doped fiber 4, a low-reflection grating 5, a second ytterbium-doped fiber 6 and an output fiber 7.

[0031] Specifically, there are multiple LD pump sources 1, and the number of LD pump sources 1 is determined according to the required pump power. Each LD pump source 1 is connected to the input end of the fiber combiner 2, and the pump light is combined through the fiber combiner 2. The output end of the fiber combiner 2 is connected in sequence through the high-reflection grating 3, the first ytterbium-doped fiber 4, the low-reflection grating 5, the second ytterbium-doped fiber 6 and the output fiber 7. The output end of the output fiber 7 is provided with an output end cap 10, and the shape of the output end cap 10 can be a cylinder or a truncated cone. The high-reflection grating 3, the first ytterbium-doped fiber 4 and the low-reflection grating 5 constitute a resonant cavity. In addition, the length of the first ytterbium-doped fiber 4 is relatively short, only 0.2m to 10m, and the length of the second ytterbium-doped fiber 6 is relatively long, 5m to 100m. Among them, the supercontinuum light source device uses an LD pump source for pumping, which can not only make the continuous spectrum conversion efficiency and output power higher, but also change the pump wavelength or use cascade pumping.

[0032] The working principle of the supercontinuum light source device in this embodiment is:

[0033] The pump light generated by each LD pump source 1 enters the first ytterbium-doped fiber 4. Since the length of the first ytterbium-doped fiber 4 is relatively short, the resonant cavity operates in an unstable region, thereby generating a pulsed laser. Then, the pulsed laser is injected into the second ytterbium-doped fiber 6 as a seed light source, and the pump light that is not absorbed in the first ytterbium-doped fiber 4 is also injected into the second ytterbium-doped fiber 6 to become the pump light of the second ytterbium-doped fiber 6. After the second ytterbium-doped fiber 6 absorbs the pump light, an ion number inversion distribution is formed. At this time, the pulsed laser generated in the first ytterbium-doped fiber 4 will form laser power amplification in the second ytterbium-doped fiber 6. Since the length of the second ytterbium-doped fiber 6 is relatively long, the pulsed laser will generate amplified pulsed laser in the second ytterbium-doped fiber 6, and will also generate spectrum broadening due to nonlinear effects such as self-phase modulation, four-wave mixing, and stimulated Raman scattering, thereby triggering the output of a supercontinuum light source, and the maximum output power of the supercontinuum light source can reach 300W to 400W. In addition, in this embodiment, the spectrum broadening and output conditions can be increased by changing the length and parameter types of the first ytterbium-doped optical fiber 4 and the second ytterbium-doped optical fiber 6.

[0034] The supercontinuum light source output by the supercontinuum light source device is tested, such as Figure 3 As shown, the supercontinuum light source device has a wavelength range of 1053nm to 1373nm and a coverage range of 320nm under a supercontinuum output power of 70W; Figure 4 As shown, by measuring the relationship between the laser pump power and the supercontinuum output power (laser output power) of the supercontinuum light source device, it can be found that the light-to-light conversion efficiency of the supercontinuum light source device is above 70%.

[0035] In summary, in the supercontinuum light source device of this embodiment, the pump light generated by the LD pump source is input into the shorter first ytterbium-doped optical fiber to generate a laser in the form of a high-peak pulse, and then the power is amplified and the spectrum is broadened through the second ytterbium-doped optical fiber to achieve supercontinuum laser output. The supercontinuum light source device has the advantages of simple structure, low manufacturing cost, good output stability and high light-to-light conversion efficiency.

[0036] In this embodiment, the total power of each LD pump source 1 is 10W to 600W. When the pump power is lower than 10W, the resonant cavity does not work; as the pump power increases, the laser broadening becomes narrower; when the pump power exceeds 600W, the pump conversion rate is sufficient to reach a stable state in the cavity, the supercontinuum disappears, and the high-power pulsed laser becomes a continuous laser.

[0037] In addition, the reflectivity of the high-reflection grating is 50% to 99.9%, the reflectivity of the low-reflection grating is 5% to 50%, the core diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 5μm to 35μm, and the cladding diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 100μm to 500μm. By setting the above parameters, the light-to-light conversion efficiency of the supercontinuum light source device can be made higher. Preferably, the core diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 20μm, and the cladding diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 400μm.

[0038] In addition, if Figure 1 As shown, the supercontinuum light source device further includes a red light laser 8 .

[0039] The red laser 8 is connected to the input end of the optical fiber combiner 2. In this way, the visible red light emitted by the red laser 8 can be used to determine whether there is a problem with the optical path of the supercontinuum light source device.

[0040] In addition, if Figure 1 As shown, the supercontinuum light source device further includes a cladding light filter 9 .

[0041] Specifically, the cladding light filter 9 is arranged between the second ytterbium-doped optical fiber 6 and the output optical fiber 7, and is used to strip the cladding light in the optical fiber. The cladding light filter can be formed on the output optical fiber, for example, the outer surface of the cladding of the output optical fiber is processed into a rough surface. At the same time, a cold water liquid pipe can be arranged on the outside of the cladding light filter to cool the cladding light filter, so as to make the supercontinuum light source device work stably and continuously for a long time.

[0042] Furthermore, the fiber combiner, the high-reflection grating, the first ytterbium-doped fiber and the low-reflection grating are fused in sequence, and the second ytterbium-doped fiber and the cladding light filter are fused. In this way, the various components in the supercontinuum light source device can be assembled flexibly, thereby facilitating the assembly line production of the supercontinuum light source device.

[0043] In other embodiments, Figure 2 As shown, the supercontinuum light source device further includes a third ytterbium-doped optical fiber 11 .

[0044] The third ytterbium-doped fiber 11 is arranged between the second ytterbium-doped fiber 6 and the output fiber 7. At this time, the cladding light filter 9 is located between the third ytterbium-doped fiber 11 and the output fiber 7. By arranging the third ytterbium-doped fiber 11, the output power of the supercontinuum light source device can be increased or the conversion efficiency can be changed. Among them, the length of the third ytterbium-doped fiber can be 5m to 100m, the core diameter of the third ytterbium-doped fiber is 15μm to 60μm, and the cladding diameter of the third ytterbium-doped fiber is 150μm to 800μm.

[0045] The above description is only a specific implementation of the present invention. Under the above teaching of the present invention, those skilled in the art can make other improvements or modifications based on the above embodiments. Those skilled in the art should understand that the above specific description is only to better explain the purpose of the present invention, and the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A supercontinuum light source device, characterized in that: It includes an LD pump source, a fiber combiner, a high-reflection grating, a first ytterbium-doped fiber, a low-reflection grating, a second ytterbium-doped fiber, an output fiber and an output end cap; The number of the LD pump sources is multiple, each of the LD pump sources is connected to the input end of the fiber combiner, the output end of the fiber combiner is sequentially connected through the high-reflection grating, the first ytterbium-doped fiber, the low-reflection grating, the second ytterbium-doped fiber, the output fiber and the output end cap, and the high-reflection grating, the first ytterbium-doped fiber and the low-reflection grating constitute a resonant cavity; The length of the first ytterbium-doped optical fiber is 0.2 m to 10 m, and the length of the second ytterbium-doped optical fiber is 5 m to 100 m.

2. The supercontinuum light source device according to claim 1, characterized in that: Also included is a third ytterbium-doped optical fiber; The third ytterbium-doped optical fiber is disposed between the second ytterbium-doped optical fiber and the output optical fiber.

3. The supercontinuum light source device according to claim 1, characterized in that: The reflectivity of the high-reflection grating is 50% to 99.9%.

4. The supercontinuum light source device according to claim 1, characterized in that: The reflectivity of the low-reflection grating is 5% to 50%.

5. The supercontinuum light source device according to claim 1, characterized in that: The total power of each LD pump source is 10W to 600W.

6. The supercontinuum light source device according to claim 1, characterized in that: The core diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 5 μm to 35 μm, and the cladding diameters of the first ytterbium-doped optical fiber and the second ytterbium-doped optical fiber are both 100 μm to 500 μm.

7. The supercontinuum light source device according to claim 1, characterized in that: Also included is a red laser; The red light laser is connected to the input end of the optical fiber combiner.

8. The supercontinuum light source device according to any one of claims 1 to 7, characterized in that: Also included is a cladding light filter; The cladding light filter is arranged between the second ytterbium-doped optical fiber and the output optical fiber.

9. The supercontinuum light source device according to claim 8, characterized in that: The fiber combiner, the high-reflection grating, the first ytterbium-doped fiber and the low-reflection grating are fused in sequence, and the second ytterbium-doped fiber and the cladding light filter are fused.

Images