Fully passive logic using 1-GHz in-fibre phase filters

Abstract

We report realization of an integrated (all-pass) phase-only filter with a record frequency resolution of 1 GHz (at least 10× improvement compared to a waveshaper) using Bragg grating technology in an all-fibre platform. The phase filter is utilized to realize high-speed fully-passive NOT and XNOR logic operations in a cm-long structure.