Investigation of peak wavelength detection of fiber Bragg grating with sparse spectral data

Abstract

A simple equation for peak wavelength detection of fiber Bragg grating (FBG) with three spectral data is proposed, which has almost the same order of computing load as the conventional maximum search algorithm and uncertainty as the least-squares fit algorithm. The factors effecting performance of the new technique was investigated by simulation. For FBG with spectral bandwidth 0.2 nm, simulation results show that sample resolution lying between 0.07 and 0.16 nm have small measure standard deviation, which is less than 1 pm for SNR greater than 20.75 dB. Experiments were carried out with FBG and interrogator based on InGaAs linear array, and the results verified the effectiveness of the new technique.