Practical, rapid, and process-on-place polymer-free cladding power stripping for high power fiber lasers

We have studied polymer-free cladding power strippers for high-power fiber laser applications. A practical, rapid, and process-on-place chemical etching technique is presented to form surface roughness for efficient removal of the cladding light. The technique is methodically studied and performance contours are determined for frequently used 130, 250, and 400 mu m double-clad fibers. The stripping efficiency and the thermal performance of the fabricated strippers are investigated with respect to such process parameters as etching time and etched fiber length. At least 15 dB attenuation with < 0.045 (degrees C/W) thermal slope is demonstrated for all fiber types. To show the power scalability of the proposed technique, similar to 600 W power is stripped with an ultra-lowthermal slope of similar to 0.021(degrees C/W) over a 400 m fiber. (C) 2020 Optical Society of America