Low-cost fiber grating sensor demodulator using a temperature-compensated fiber grating spectral filter

Abstract

A simple, potentially low cost fiber grating demodulation is described that can be used to measure very fast strain events. The unit consists of a broadband light emitting diode light source that is used to illuminate a fiber grating. The narrow band reflected light signal is directed toward a broadband chirped fiber grating whose transmission and reflection is monitored by a pair of receivers. The ratioed output can be used to monitor fast events. An example of using this sensor to support impact testing is given.