Conversion of phase modulation of light into intensity modulation by means of an external fiber-optic interferometer

A new method of detecting phase modulation, based on using an “external” optical waveguide interferometer, is considered. This “detection” is weakly dependent on the length, position, and external conditions of the propagation channel for the phase-modulated light and, in many cases may prove more efficient than conventional methods of constructing phasemodulated fiber-optic systems. Pis’ma Zh. Tekh. Fiz. 23, 9–16 (May 26, 1997)