Silicon-microring-based interrogator for TDM-FBG sensors enabled by pulse compression

We propose a silicon microring resonator (MRR)-based high-resolution interrogator enabled by novel slope-assisted filtering and pulse compression technology for time division multiplexed fiber Bragg grating (TDM-FBG) sensors. Golay coded optical pulses are launched into an FBG sensor array to produce a series of reflected pulses with different time delays due to various transmission distances. A tunable MRR filter is used for interrogation of all FBG sensors by direct detection and subsequent signal processing. As a proof of concept, a strain sensing experiment is conducted using a 2×1 TDM-FBG sensor array. The performance of the proposed interrogation system is evaluated experimentally, and the dynamic strain resolution can be as high as 20ne/Hz.