Heat suppression of the fiber coating on a cladding light stripper in high-power fiber laser

摘要

We present a theoretical model for the thermal effect of the fiber coating on a high-power cladding light stripper, which is fabricated by chemical etching. For the input and output of the fiber coating, a novel segmented corrosion method and increasing attenuation method are proposed for heat suppression, respectively. The relationship between the attenuation and temperature rise of the fiber coating at the output is experimentally demonstrated. The temperature distribution of the fiber coating at the input as well as the return light power caused by scattering are measured for the etched fiber with different surface roughness values. The results suggest that the rise in temperature is primarily caused by the scattering light propagating into the coating. Finally, an attenuation of 27 dB is achieved. At a room temperature of 23 degrees C and input pump power of 438 W, the highest temperature of the input fiber coating decreases from 39.5 degrees C to 27.9 degrees C by segmented corrosion, and the temperature rise of the output fiber coating is close to 0. (C) 2018 Optical Society of America