Adaptive polarization-insensitive detection of optical phase modulation with a single detector

A single-detector adaptive configuration for polarization-insensitive homodyne detection of optical phase modulation is proposed. Experiments were performed at a HeNe laser wavelength ( λ=633 nm) and employed GaAs photo-EMF adaptive detectors. It has been shown that residual fluctuations in the output signal are basically due to nonlinearity of the adaptive photodetector response to the intensity of the polarization-modulated signal wave.