Optical wavelength discriminator with uniform fiber Bragg grating for demodulation of bipolar signals

In the paper the results off simulation and experimental investigation are presented of a optical wavelength discriminator with an apodized uniform fiber Bragg grating. To obtain the discrimination off bipolar signals, the central wavelengths off the sensor grating and the discriminator gratings differ by a half of their bandwidth. From the carried out results it follows, that the nonlinearity error of the conversion characteristic of the discriminator is less than 1%. The range of linear operation of the discriminator amounts to +/- 145 muepsilon. It is limited not only by the bandwidth off the gratings, beat also by the attenuation off the reflected beans on the way between the sensing and reference gratings.