掺镱光纤辐致损耗空间分布测量OA

Yb-doped fiber(YDF)serves as the core gain medium for high-power lasers in the 1 μm waveband.However,in a gamma radiation environment,numerous color-center defects are readily generated inside the fiber,which induce radiation-induced attenuation and consequently degrade the performance of the fiber and laser system.This paper experimentally investigates the spatial distribution characteristics of radiation-induced attenuation in YDF and the corresponding measurement methods.Optical frequency domain reflectometry(OFDR)and the conventional transmission attenuation method were employed to quantitatively measure the radiation-induced attenuation of YDF at the 1.5 μm band under an irradiation dose of 600 Gy.Comparative analysis shows that the results obtained by the two methods are basically consistent,verifying the feasibility and reliability of OFDR in the quantitative measurement of fiber radiation-induced attenuation.To realize the rapid conversion of radiation-induced attenuation at different wavelength bands,a dual-band synchronous measurement scheme was designed,and the conversion coefficient of radiation-induced attenuation between the 1 μm and 1.5 μm wavebands was experimentally determined to be approximately 2.44.Finally,the spatial loss distribution of the fiber after irradiation and bleaching treatment was obtained via OFDR.It is confirmed that distinct spatial inhomogeneity still remains after bleaching phenomenon.