Optical FM Demodulation by Fibre Bragg Grating

In this paper the application of fibre Bragg grating (FBG) as a FM demodulator is presented. Two types of FBG were investigated: with and without athermal package. Main factors limited application of FBG to FM demodulation such as thermal stability, slope of the FBG and dark current of photodetector were discussed. Maximum and minimum FM deviation possible to demodulate for investigated FBG was calculated.