A single-mode fiber evanescent grating reflector

Backward wave coupling is demonstrated by placing a first-order metal grating in the evanscent field of a single-mode fiber. Guided reflections as high as 38 percent were observed. The device acts as a polarization and frequency filter for both reflected and transmitted light. Polarization extinction ratios greater than 20 and 15 dB were obtained for reflected and transmitted light, respectively.