Surface corrugation Bragg gratings on optical fiber tapers created via plasma etch postprocessing

We describe a reflection-based fiber filter fabricated by plasma etching a surface corrugation Bragg grating on a tapered single-mode fiber. The taper waist with the grating forms the functional part of the filter, and the adiabatic taper transition removes unwanted higher-order modes. The spectral response is controlled by varying the taper diameter while maintaining a constant grating period. Reflection spectra have been investigated theoretically and experimentally and found to be in good agreement.