Blue light generating device based on thulium-doped optical fiber

Abstract

The utility model provides a thulium-doped optical fiber-based blue light generating device, which comprises a pumping source, a wavelength division multiplexer, a thulium-doped optical fiber, a cladding light stripper and an optical fiber reflector, the optical fiber reflector and the pumping source are respectively connected with the input end of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected with the input end of the thulium-doped optical fiber, and the thulium-doped optical fiber is connected with the cladding light stripper. The output end of the thulium-doped optical fiber is connected with the input end of the cladding light stripper; the thulium-doped optical fiber is provided with a fiber core, an inner cladding and an outer cladding, and pump light emitted by the pump source is transmitted in the inner cladding; wherein the thulium-doped optical fiber is used for being pumped by the cladding to sequentially generate first blue light and second blue light, and the first blue light and the second blue light are output through the cladding light stripper. The blue light generating device based on the thulium-doped optical fiber provided by the utility model aims to solve the problems of poor stability, complex structure and the like of a blue light source system in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of optical equipment, in particular to a blue light generating device based on thulium-doped optical fiber. Background Art

[0002] Blue light sources are widely used, mainly as ideal light sources for laser projection, laser television, laser underwater communication, etc. At present, the common method for obtaining blue light is to first generate 900-1000nm laser, insert a frequency doubling crystal in the optical path composed of discrete optical components, and then double the frequency to obtain 450-500nm blue light output. For example, cladding pumping is used to perform intracavity frequency doubling to obtain a high-power blue light fiber laser, a blue light laser generation method and device based on the quadruple frequency of a thulium-doped fiber laser, and a 469nm high-power blue light fiber laser with a frequency doubling cavity structure composed of a converging fiber frequency doubler and three fiber gratings. All of the above methods and devices for generating blue light sources use a frequency doubling method and insert discrete components, resulting in defects such as poor stability and complex structure in the entire blue light source system. Utility Model Content

[0003] The utility model provides a blue light generating device based on thulium-doped optical fiber, aiming to solve the problems of poor stability and complex structure of the blue light source system in the traditional technology.

[0004] In view of the problems existing in the prior art, the embodiment of the utility model provides a blue light generating device based on thulium-doped optical fiber, comprising a pump source, a wavelength division multiplexer, a thulium-doped optical fiber, a cladding light stripper and an optical fiber reflector, wherein the optical fiber reflector and the pump source are respectively connected to the input end of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected to the input end of the thulium-doped optical fiber, and the output end of the thulium-doped optical fiber is connected to the input end of the cladding light stripper; the thulium-doped optical fiber has a core, an inner cladding and an outer cladding, and the pump light emitted by the pump source is transmitted in the inner cladding;

[0005] The thulium-doped optical fiber is used to be cladding pumped to sequentially generate a first blue light and a second blue light, and the first blue light and the second blue light are output through the cladding light stripper.

[0006] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, the pump source includes a semiconductor laser with a pigtail output or a fiber laser with a pigtail output.

[0007] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, the central wavelength of the pump source is 1050-1100nm, and the bandwidth is 8-12nm.

[0008] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, the input end of the thulium-doped optical fiber is aligned with the wavelength division multiplexer, and the output end of the thulium-doped optical fiber is aligned with the cladding light stripper.

[0009] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, optical fiber glue is coated on the fusion point of the thulium-doped optical fiber.

[0010] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, the wavelength division multiplexer includes a (1+1)*1 type optical fiber tapered wavelength division multiplexer.

[0011] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, the insertion loss of the optical fiber tapered wavelength division multiplexer is ≤0.5dB, the operating wavelength is 1050-1100nm and 400-480nm, and the output pigtail of the optical fiber tapered wavelength division multiplexer matches the mode field diameter of the thulium-doped optical fiber.

[0012] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, the optical fiber reflector comprises an optical fiber reflector with a pigtail output, the working wavelength of the optical fiber reflector with a pigtail output is 400-480nm, and the optical fiber end face is plated with a reflective silver film.

[0013] According to a blue light generating device based on thulium-doped optical fiber provided by the utility model, the cladding light stripper has an output optical fiber, the output optical fiber matches the mode field diameter of the thulium-doped optical fiber, the operating wavelength of the cladding light stripper is 400-480nm, the stripping degree is 100W, and the insertion loss is ≤0.5dB.

[0014] The utility model provides a blue light generating device based on thulium-doped fiber, which is connected in sequence by optical fiber through a pump source, a wavelength division multiplexer, a thulium-doped fiber, a cladding light stripper, and an optical fiber reflector. The pump source cladding pumps the thulium-doped fiber to form an oscillating amplification cavity, generating spontaneous radiation light transmitted in the forward direction and the reverse direction. The spontaneous radiation light transmitted in the forward direction is continuously absorbed and amplified by the thulium-doped fiber to form a first blue light. The spontaneous radiation light transmitted in the reverse direction is reflected by the optical fiber reflector, returns to the thulium-doped fiber and is amplified again to form a second blue light, which is superimposed with the first blue light to form a double-pass blue light, thereby obtaining a blue light output with higher conversion efficiency. The utility model overcomes the problem of complex structure and poor stability in traditional frequency doubling fiber lasers, adopts an all-fiber structure, does not require a frequency doubling crystal, and does not require adjustment of discrete components. It has high reliability and has the advantages of simple structure, easy operation, and good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 It is a structural schematic diagram of a blue light generating device based on thulium-doped optical fiber provided by the utility model. DETAILED DESCRIPTION

[0017] The following is a further detailed description of the implementation methods of the utility model in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the utility model, but cannot be used to limit the scope of the utility model. In the description of the embodiments of the utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the embodiments of the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the utility model. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0018] In the description of the embodiments of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0019] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0020] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model embodiment. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0021] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in 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.

[0022] Combine the following Figure 1 The utility model describes a blue light generating device based on thulium-doped optical fiber.

[0023] In view of the problems of poor stability and complex structure of the blue light source system in the traditional technology, the utility model provides a blue light generating device based on thulium-doped optical fiber, comprising a pump source, a wavelength division multiplexer, a thulium-doped optical fiber, a cladding light stripper and an optical fiber reflector, wherein the optical fiber reflector and the pump source are respectively connected to the input end of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected to the input end of the thulium-doped optical fiber, and the output end of the thulium-doped optical fiber is connected to the input end of the cladding light stripper;

[0024] Specifically, the thulium-doped fiber is used to be cladding pumped to generate spontaneous radiation light transmitted in the forward direction and the reverse direction (the forward direction and the reverse direction can be regarded as the forward direction and the reverse direction in the present utility model). The spontaneous radiation light transmitted in the forward direction is absorbed and amplified by the thulium-doped fiber to form the first blue light transmitted in the forward direction. The spontaneous radiation light transmitted in the reverse direction is reflected back to the thulium-doped fiber by the fiber reflector and absorbed and amplified to form the second blue light transmitted in the forward direction. The first blue light and the second blue light are superimposed to form the blue light of the double-pass front and back, thereby obtaining a blue light output with higher conversion efficiency. The present utility model overcomes the problem of complex structure and poor stability in the traditional frequency doubling fiber laser. It adopts an all-fiber structure, does not require a frequency doubling crystal, and does not require adjustment of discrete components. It has high reliability and has the advantages of simple structure, easy operation, good stability, etc. It should be noted that the thulium-doped optical fiber is doped with the rare earth element thulium. The utility model uses cladding pumping to excite the thulium-doped optical fiber. The rare earth particles in the ground state are excited to a high energy level, and then transition downward to the next energy level without radiation. At the same time, some rare earth particles will undergo an up-conversion process to transition to a high energy level, and then transition to the next high sub-energy level without radiation, and then return to the ground state and emit blue light. It should be noted that the thulium-doped optical fiber has a core, an inner cladding and an outer cladding, and the pump light emitted by the pump source is transmitted in the inner cladding.

[0025] Specifically, in an optional embodiment, the pump source includes a semiconductor laser with a pigtail output or a fiber laser with a pigtail output. The central wavelength of the pump source is 1050-1100 nm, and the bandwidth is 8-12 nm.

[0026] Furthermore, in order to achieve high-quality fusion splicing of thulium-doped optical fiber, the input end of the thulium-doped optical fiber and the wavelength division multiplexer, and the output end and the cladding light stripper are fused by cladding alignment fusion splicing and segmented discharge fusion splicing, that is, the cladding of the thulium-doped optical fiber and its two adjacent structures are butted. The above method can reduce the pre-fusion time and pre-fusion power of the thulium-doped optical fiber on the one hand, and reduce the main discharge time and power on the other hand, in order to reduce the temperature of the optical fiber fusion position during the segmented interval time, reduce the fusion loss, and achieve high-quality, stable and low-loss fusion. Specifically, the segmented discharge fusion method adopts a two-stage discharge fusion method, the first stage fusion power is 4500-5000bit, the discharge time is greater than or equal to 4000ms, and the second stage fusion power is 4000-5000bit, and the discharge time is greater than or equal to 5000ms.

[0027] Furthermore, after the thulium-doped optical fiber is fused by the cladding alignment fusion method and the segmented discharge fusion method, the method further includes: using an optical fiber coating machine to secondary coat the fusion point of the thulium-doped optical fiber. That is, the fusion point of the thulium-doped optical fiber is coated with optical fiber glue, and the cured optical fiber glue can improve the mechanical strength of the fusion point.

[0028] In an optional embodiment, the wavelength division multiplexer includes a fiber taper type wavelength division multiplexer, specifically a (1+1)×1 fiber taper type wavelength division multiplexer. The insertion loss of the fiber taper type wavelength division multiplexer is ≤0.5dB, the operating wavelength is 1050-1100nm and 400-480nm, and the output pigtail of the fiber taper type wavelength division multiplexer matches the mode field diameter of the thulium-doped optical fiber.

[0029] Furthermore, the fiber reflector includes a fiber reflector with a pigtail output, the working wavelength of the fiber reflector with a pigtail output is 400-480nm, and the fiber end face is coated with a reflective silver film. With such an arrangement, an average of ≥97.5% of the full-band light can be reflected back into the optical fiber, so that the reversely transmitted spontaneous radiation light is reflected by the fiber reflector, passes through the wavelength division multiplexer, and after being absorbed and amplified by the thulium-doped optical fiber, the backward and forward spontaneous radiation light forms a forward and backward double-pass all-fiber optical path structure, thereby obtaining a more powerful blue light stable output. Compared with the optical path of the inserted multi-stage frequency doubling crystal or unit, there is no need for free space coupling, and the optical path is simpler and more stable.

[0030] Furthermore, the operating wavelength of the cladding light stripper is 400-480nm, the stripping degree is 100W, and the insertion loss is ≤0.5dB.

[0031] The blue light generating device based on thulium-doped optical fiber provided by the utility model has the following advantages:

[0032] 1. It is composed of a pump source, a wavelength division multiplexer, a thulium-doped fiber, a cladding light stripper, and a fiber reflector connected in sequence through optical fibers. The pump source cladding pumps the thulium-doped fiber to form an oscillating amplification cavity, generating spontaneous radiation light transmitted in the forward direction and the reverse direction. The spontaneous radiation light transmitted in the forward direction is continuously absorbed and amplified by the thulium-doped fiber to form the first blue light. The spontaneous radiation light transmitted in the reverse direction is reflected by the fiber reflector, returns to the thulium-doped fiber and is amplified again to form the second blue light, which is superimposed with the first blue light to form the blue light before and after the double-pass, thereby obtaining a blue light output with higher conversion efficiency;

[0033] 2. It overcomes the problem of complex structure and poor stability in traditional frequency-doubling fiber lasers. It adopts an all-fiber structure, does not require frequency-doubling crystals, and does not require discrete components to be adjusted. It has high reliability, simple structure, easy operation, good stability, etc. The utility model overcomes the problem of complex structure and poor stability in traditional frequency-doubling fiber lasers. It adopts an all-fiber structure, does not require frequency-doubling crystals, and does not require discrete components to be adjusted. It has high reliability, simple structure, easy operation, good stability, etc.

[0034] 3. The fusion splicing of thulium-doped optical fiber adopts the cladding alignment method and the segmented discharge fusion splicing method. On the one hand, it can reduce the pre-fusion time and pre-fusion power of the thulium-doped optical fiber, and on the other hand, reduce the main discharge time and power. The purpose is to reduce the temperature of the optical fiber fusion position in the segmented interval time, reduce the fusion loss, and achieve high-quality, stable and low-loss fusion; in addition, the fusion point is coated twice by the optical fiber coating machine, which greatly improves the mechanical strength of the fusion point.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A blue light generating device based on thulium-doped optical fiber, characterized in that: It comprises a pump source, a wavelength division multiplexer, a thulium-doped optical fiber, a cladding light stripper and an optical fiber reflector, wherein the optical fiber reflector and the pump source are respectively connected to the input end of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected to the input end of the thulium-doped optical fiber, and the output end of the thulium-doped optical fiber is connected to the input end of the cladding light stripper; the thulium-doped optical fiber has a core, an inner cladding and an outer cladding, and the pump light emitted by the pump source is transmitted in the inner cladding; The thulium-doped optical fiber is used to be cladding pumped to sequentially generate a first blue light and a second blue light, and the first blue light and the second blue light are output through the cladding light stripper.

2. The blue light generating device based on thulium-doped optical fiber according to claim 1, characterized in that: The pump source includes a semiconductor laser with a pigtail output or a fiber laser with a pigtail output.

3. The blue light generating device based on thulium-doped optical fiber according to claim 2, characterized in that: The central wavelength of the pump source is 1050-1100 nm, and the bandwidth is 8-12 nm.

4. The blue light generating device based on thulium-doped optical fiber according to claim 1, characterized in that: The input end of the thulium-doped optical fiber is cladding-aligned with the wavelength division multiplexer, and the output end is cladding-aligned with the cladding light stripper.

5. The blue light generating device based on thulium-doped optical fiber according to claim 4, characterized in that: Optical fiber glue is coated on the fusion point of the thulium-doped optical fiber.

6. The blue light generating device based on thulium-doped optical fiber according to claim 1, characterized in that: The wavelength division multiplexer comprises a (1+1)*1 type optical fiber tapered wavelength division multiplexer.

7. The blue light generating device based on thulium-doped optical fiber according to claim 6, characterized in that: The insertion loss of the optical fiber tapered wavelength division multiplexer is ≤0.5dB, the working wavelength is 1050-1100nm and 400-480nm, and the output pigtail of the optical fiber tapered wavelength division multiplexer matches the mode field diameter of the thulium-doped optical fiber.

8. The blue light generating device based on thulium-doped optical fiber according to claim 1, characterized in that: The optical fiber reflector comprises an optical fiber reflector with a pigtail output, the working wavelength of the optical fiber reflector with a pigtail output is 400-480nm, and the optical fiber end face is plated with a reflective silver film.

9. The blue light generating device based on thulium-doped optical fiber according to claim 1, characterized in that: The cladding light stripper has an output optical fiber, the output optical fiber matches the mode field diameter of the thulium-doped optical fiber, the working wavelength of the cladding light stripper is 400-480nm, the stripping degree is 100W, and the insertion loss is ≤0.5dB.

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