Signal detection algorithms for interferometric sensors with harmonic phase modulation: evaluation of additive noise effects.

Interferometric techniques are widely used for interrogation of various optical sensors. Techniques utilizing harmonic auxiliary phase modulation are of special interest from a practical point of view, as they do not require a large bandwidth and dynamic range of a phase modulator, yet are capable of accurately demodulating target phase signals when jointed with proper demodulation algorithms. The current paper presents a universal theoretical apparatus aimed at estimating the influence of the noise of an interference signal on noise of the demodulated phase.