Fabrication of high-rejection, low-loss filters by the concatenation of broadly chirped fibre Bragg gratings

Abstract

Single- and multiple-bandpass filters with broad, high- rejection stopbands and narrow, low-loss passbands are significant components for fiber networks. Hitherto, this combination of characteristics has proved elusive using in- fiber grating techniques. Here, we report the realization of practical single-passband filters synthesized from concatenated chirped broadband fiber gratings written holographically in a highly photosensitive fiber. Practical, low-loss (< 2 dB), single-passband fiber Bragg grating transmission filters have been fabricated with greater than 30 dB out-of-band rejection over a 25 nm spectral width. ©2005 Copyright SPIE - The International Society for Optical Engineering.