Parameter comparison of fiber Bragg grating based optical wavelength discriminators

Fiber Bragg gratings (FBGs) are widely used as temperature and strain measurement systems and in telecommunications systems. In order to simplify detecting the wavelength change (which is the output signal from FBB), fiber Bragg grating based optical wavelength discriminators can be used. In this paper, discriminators with apodized, chirped FBG cooperating with the identical grating of a sensor are considered. The analysis includes: the processing range (assuming the nonlinearity characteristic is less than 1%), the processing equation and the range of strain measurement. On the basis of simulation tests, there is discussed the influence of the following parameters: chirp value (Subsection 3.1), length (Subsection 3.2) and constant refractive index change averaged over the grating period (Subsection 3.3) of selected FBGs on the discriminator characteristic.