Light darkening test device and method for ytterbium-doped silica fiber of all-fiber structure

Abstract

The invention discloses an ytterbium-doped silica fiber light darkening test device of an all-fiber structure. Signal light output by a signal source is attenuated by an optical fiber flange and an optical fiber attenuator in sequence, and then is combined with pump light output by a first pump source through a wavelength division multiplexer to form combined beam light; the combined light and thepump light output by the second pump source are respectively input through the signal end and the pump end of an optical fiber beam combiner; output light of the optical fiber beam combiner is transmitted along the ytterbium-doped optical fiber, the output end of the ytterbium-doped optical fiber is connected with the input end of a cladding light stripper in a welded mode, and an output light beam of the cladding light stripper enters an optical power detector through a low-photon darkening filtering optical fiber. The low-photon darkening filtering optical fiber is a Yb-doped optical fiber;and the concentration of doped Yb2O3 is not higher than 0.1 wt%. The light darkening test device has the beneficial effects that the light darkening test device is of the all-fiber structure, a testsystem is compact in structure, the test method is simple, the device cost is low, the signal source power can be accurately regulated and controlled, the test condition is optimized, and the test signal-to-noise ratio is high.

Description

technical field [0001] The invention relates to the field of optical fiber testing, in particular to an all-fiber-structured ytterbium-doped silica optical fiber light-darkening testing device and method. Background technique [0002] With the rapid development of special optical fiber preparation technology and fiber laser technology, the laser output power of fiber lasers has been continuously improved, which has also continuously expanded the application scope of fiber lasers. From laser marking under lower power conditions, to higher power laser processing, such as laser cutting, laser drilling, laser marking, laser welding and so on. Due to the simple energy level structure of ytterbium ions, small quantum deficit, and mature commercial semiconductor lasers at the absorption peak of ytterbium ions, ytterbium-doped fiber lasers lead the rapid development of high-power fiber lasers. However, when fiber lasers work under high power conditions for a long time, the laser ou...

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Problems solved by technology

[0005] However, in this application, the inventor found that the existing photo-darkening test device has the following problems during the implementation of the present invention: the existing strong light test method for the photo-darkening effect of ytterbium-doped optical fiber, by using ~1μm The high-energy laser is used as the detection light source, and the wavelength of the detection light is far away from the photo-darkening "color center" in the ultraviolet-visible band. The photo-darkening effect is not obvious, and it is difficult to detect the photo-darkening performance of ytterbium-doped optical fiber with low photon darkening effect; The weak light test method of the existing gain fiber photon darkening test system, the patent is sequentially connected to a collimator lens, a semiconductor laser output wavelength filter, a gain fiber excitation wavelength filter and a narrow-band optical filter at the output end of the gain fiber. When the unabsorbed high-energy pump light passes through the collimating lens and three filters, the thermal effect will affect the stability of the test system, and the collimating lens and three filters are connected between the output end of the gain fiber and the power meter , the system structure is complex, and the stability of the optical structure is poor, which affects the stability of the test system

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