Cladding Light Stripper of High Average Stripped Power Density With High Attenuation of 39 dB and Low Temperature Rise

We demonstrate a 150-mm long cladding light stripper for kW-level operation with high attenuation and low temperature rising. The first 100 mm of the device was designed based on theoretical simulation to achieve uniform extraction of the high-power scattered cladding light and it was constructed by self-developed experimental device for continuous gradient chemical etching. While in the last 50 mm, we reduced the cladding diameter from 400 to 65 μm and then roughed the surface to extract the residual low NA cladding light more efficiently. The power handling capability of this design was tested up to 1.01 kW for an hour stably without causing any damage. The cladding light stripper achieved a high attenuation of 39 dB and a low temperature elevation of 0.05 °C/ input-Watt under the condition of air cooling. The maximum temperature on the surface of the device was only 78.5 °C with an average stripped power density of 7.156 × 10
⁶
W/m
²
. To the best of our knowledge, the cladding light stripper reported here has the highest average stripped power density and attenuation coefficient without compromising temperature performance. This cladding light stripper is well suitable for application in multikilowatts class fiber lasers.