A kind of triple-clad thulium-doped optical fiber and its preparation method

Abstract

The invention provides a three-wrapping-layer thulium-doped optical fiber and a preparation method thereof. The three-wrapping-layer thulium-doped optical fiber comprises a fiber core, an inner wrapping layer, an outer wrapping layer and a resin layer. The fiber core comprises silicon dioxide, thulium oxide, aluminum oxide and phosphorus pentoxide, wherein the molar content of the thulium oxide is 0.2-0.8%, the molar content of the phosphorus pentoxide is 0.5-1.0%, and the molar ratio of the aluminum oxide to the thulium oxide is larger than or equal to 8; the diameter d1 of the fiber core ranges from 10 microns to 30 microns. The surface of the fiber core is sleeved with the inner wrapping layer. The inner wrapping layer comprises doping agents and silicon dioxide. The diameter of the inner wrapping layer is d2 which meet the relational expression: 2.5d1<=d2<=4d1. The surface of the inner wrapping layer is sleeved with the outer wrapping layer. The outer wrapping layer comprises silicon dioxide. The surface of the outer wrapping layer is sleeved with the resin layer. According to the three-wrapping-layer thulium-doped optical fiber, the numerical aperture of the fiber core is reduced by controlling the components in the inner wrapping layer, the content of the components in the fiber core, the diameter of the fiber core and the diameter of the inner wrapping layer, and the slope efficiency and the beam quality of output lasers are improved.

Description

technical field

[0001] The invention relates to the field of thulium-doped optical fibers, in particular to a triple-clad thulium-doped optical fiber and a preparation method thereof. Background technique

[0002] Fiber lasers are widely used in medical, military, optical communication and industrial processing fields due to their advantages of high efficiency, good beam quality, high reliability, compact structure and good heat dissipation. Thulium-doped fiber laser is a new type of high-power laser, which uses thulium-doped silica fiber as the gain medium, and operates at a wavelength of 2 μm, which is in the wavelength range of human eye safety. With the improvement of fiber design and preparation process and the development of semiconductor laser pumping technology, 2μm band thulium-doped fiber laser has been developed rapidly. Thulium-doped fiber laser can provide long-wave laser oscillation with a wavelength of about 2 μm, which is close to the absorption peak of wate...

Examples

preparation example Construction

[0042] The present invention provides a method for preparing a three-clad thulium-doped optical fiber described in the above technical solution, comprising the following steps:

[0043] 1) Depositing an inner cladding layer and a loose core layer on the inner surface of the quartz deposition tube in sequence;

[0044] 2) immerse the quartz deposition tube with an inner cladding and a loose core layer deposited on the inner surface obtained in the step 1) in a solution containing thulium ions and aluminum ions;

[0045] 3) Drying, sintering, and shrinking the quartz deposition tube soaked in step 2) in sequence to obtain a thulium-doped optical fiber preform, the thulium-doped optical fiber preform includes a core and an inner package that is sequentially sleeved on the surface of the core layer and outer cladding; the core includes silicon dioxide, thulium oxide, aluminum oxide and phosphorus pentoxide, the molar content of thulium oxide is 0.2 to 0.8%, and the molar content o...

Embodiment 1

[0066] After the quartz deposition tube is subjected to high-temperature flame polishing, silicon tetrachloride, germanium tetrachloride and oxygen are passed through the inner surface of the quartz deposition tube at 1970° C. to deposit an inner cladding. Then lower the temperature, pass through silicon tetrachloride, phosphorus oxychloride and oxygen, and adopt reverse deposition of loose core layer. Then move the blowtorch to the tail end of the deposition tube, raise the temperature and break the quartz deposition tube, so that the tail end of the quartz deposition tube is closed.

[0067] Remove the capped deposition tube from the lathe. Will contain 0.06mol / L of TmCl 3 ·6H 2 O and 1mol / L AlCl 3 ·6H 2 An aqueous solution of O was slowly added to the deposition tube containing the loose core layer and soaked for about 1.5 hours. Pour out the remaining solution, install the deposition tube on the lathe again, blow it with nitrogen, then raise the temperature to 1000°C,...

Embodiment 2

[0071] The quartz deposition tube is subjected to high-temperature flame polishing, and silicon tetrachloride, aluminum chloride and oxygen are passed through the inner surface of the quartz deposition tube at 1970° C. to deposit the inner cladding. Lower the deposition temperature to 1250°C, and pass through silicon tetrachloride, phosphorus oxychloride and oxygen to deposit a loose core layer. Then move the blowtorch to the tail end of the quartz deposition tube, raise the temperature to break the quartz deposition tube, and seal the tail end of the quartz deposition tube.

[0072] The quartz deposition tube was removed from the lathe, and the TmCl containing 0.08mol / L 3 ·6H 2 O and 1.5mol / L AlCl 3 ·6H 2 The O solution was slowly added to the quartz deposition tube containing the loose core and soaked for about 1 hour. Pour out the remaining solution, install the quartz deposition tube on the lathe again, turn the deposition tube, blow nitrogen into it, then raise the te...

technical field

[0001] The invention relates to the field of thulium-doped optical fibers, in particular to a triple-clad thulium-doped optical fiber and a preparation method thereof. Background technique

[0002] Fiber lasers are widely used in medical, military, optical communication and industrial processing fields due to their advantages of high efficiency, good beam quality, high reliability, compact structure and good heat dissipation. Thulium-doped fiber laser is a new type of high-power laser, which uses thulium-doped silica fiber as the gain medium, and operates at a wavelength of 2 μm, which is in the wavelength range of human eye safety. With the improvement of fiber design and preparation process and the development of semiconductor laser pumping technology, 2μm band thulium-doped fiber laser has been developed rapidly. Thulium-doped fiber laser can provide long-wave laser oscillation with a wavelength of about 2 μm, which is close to the absorption peak of wate...

Examples

preparation example Construction

[0042] The present invention provides a method for preparing a three-clad thulium-doped optical fiber described in the above technical solution, comprising the following steps:

[0043] 1) Depositing an inner cladding layer and a loose core layer on the inner surface of the quartz deposition tube in sequence;

[0044] 2) immerse the quartz deposition tube with an inner cladding and a loose core layer deposited on the inner surface obtained in the step 1) in a solution containing thulium ions and aluminum ions;

[0045] 3) Drying, sintering, and shrinking the quartz deposition tube soaked in step 2) in sequence to obtain a thulium-doped optical fiber preform, the thulium-doped optical fiber preform includes a core and an inner package that is sequentially sleeved on the surface of the core layer and outer cladding; the core includes silicon dioxide, thulium oxide, aluminum oxide and phosphorus pentoxide, the molar content of thulium oxide is 0.2 to 0.8%, and the molar content o...

Embodiment 1

[0066] After the quartz deposition tube is subjected to high-temperature flame polishing, silicon tetrachloride, germanium tetrachloride and oxygen are passed through the inner surface of the quartz deposition tube at 1970° C. to deposit an inner cladding. Then lower the temperature, pass through silicon tetrachloride, phosphorus oxychloride and oxygen, and adopt reverse deposition of loose core layer. Then move the blowtorch to the tail end of the deposition tube, raise the temperature and break the quartz deposition tube, so that the tail end of the quartz deposition tube is closed.

[0067] Remove the capped deposition tube from the lathe. Will contain 0.06mol / L of TmCl 3 ·6H 2 O and 1mol / L AlCl 3 ·6H 2 An aqueous solution of O was slowly added to the deposition tube containing the loose core layer and soaked for about 1.5 hours. Pour out the remaining solution, install the deposition tube on the lathe again, blow it with nitrogen, then raise the temperature to 1000°C,...

Embodiment 2

[0071] The quartz deposition tube is subjected to high-temperature flame polishing, and silicon tetrachloride, aluminum chloride and oxygen are passed through the inner surface of the quartz deposition tube at 1970° C. to deposit the inner cladding. Lower the deposition temperature to 1250°C, and pass through silicon tetrachloride, phosphorus oxychloride and oxygen to deposit a loose core layer. Then move the blowtorch to the tail end of the quartz deposition tube, raise the temperature to break the quartz deposition tube, and seal the tail end of the quartz deposition tube.

[0072] The quartz deposition tube was removed from the lathe, and the TmCl containing 0.08mol / L 3 ·6H 2 O and 1.5mol / L AlCl 3 ·6H 2 The O solution was slowly added to the quartz deposition tube containing the loose core and soaked for about 1 hour. Pour out the remaining solution, install the quartz deposition tube on the lathe again, turn the deposition tube, blow nitrogen into it, then raise the te...

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