A super-sensitive linear adaptive interferometer based on photorefractive BaTiO3:Co crystal

An interferometer is employed to provide high-sensitive linear detection with different polarizations of the interfering waves and polarization filtering. BaTiO₃ crystal, which provides one of the strongest grating reflectivity without resorting to an externally applied electric field, is selected for the experiments. In the experimental setup the light with vertical polarization is reflected, thus the reference beam passes the crystal without reflection by the grating, which increases the interferometer´s efficiency. The experiments have confirmed that proposed configuration of the interferometer allows linear detection of the phase modulation.