A photo-darkening test device and method for ytterbium-doped silica fiber with all-fiber structure

Abstract

The invention discloses a photo-darkening test device for ytterbium-doped silica fiber with an all-fiber structure. The signal light output by the signal source passes through the optical fiber flange and the optical fiber attenuator in turn, and then passes through the pump light output by the first pumping source. The combined beam is synthesized by the wavelength division multiplexer; the combined beam and the pump light output by the second pump source are respectively input through the signal end and the pump end of the fiber combiner, and the output light of the fiber combiner is passed along the ytterbium-doped fiber For transmission, the output end of the ytterbium-doped fiber is fused with the input end of the cladding light stripper, and the output beam of the cladding light stripper enters the optical power detector through the low photon darkening filter fiber; the low photon darkening filter fiber is the doped Yb fiber; doped with Yb 2 o 3 The concentration is not higher than 0.1%wt. The beneficial effect of the invention is that the light-darkening test device has an all-fiber structure, the test system has a compact structure, the test method is simple, the device cost is low, the power of the signal source can be precisely adjusted, the test conditions can be 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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