FBG sensor for strain measurement with enhanced sensitivity by using degenerated FWM in highly nonlinear fibre

Abstract

A method for enhancing the sensitivity of a fibre Bragg grating (FBG) sensor by all-optical signal processing is demonstrated. Degenerated four-wave mixing (FWM) has been used to perform frequency chirp magnification, which can be used for magnifying the wavelength drift of the FBG sensor. Ultra-highly sensitive measurement of the static strain has been experimentally demonstrated with strain sensitivity of 5.40 pm/. The sensitivity has been enhanced by a factor of five. © The Institution of Engineering and Technology 2013.