A Novel Method for Stripping Cladding Lights in High Power Fiber Lasers and Amplifiers

Fabrication techniques for the manufacture of a high power cladding light stripper are presented. Localized heating and thermal degradation of the recoating materials are the prime limiting factors for the operation of a high power cladding light stripper. In order to overcome this difficulty, the fiber is tapered by hydrofluoric (HF) acid and the surface of the tapered region is exposed to HF acid vapor. The acid vapor creates fine holes and scratches on the fiber surface. A low refractive index polymer is then used to recoat the fiber surface, which extracts the unwanted cladding light from the fiber over a relatively large area. This eliminates the abrupt removal of light and consequently the detrimental thermal effects due to localized heating. The power-handling capability of the device is tested under 90 W of cladding light, and attenuation of 16.7 dB is achieved.