Mapping of local complex reflection coefficient variations using a scanning multi-port homodyne interferometer

Summary form only given. We present a novel multi-port balanced homodyne interferometer scheme, that can simultaneously determine the quadrature phases of the signal beam. This interferometer consists of two identical balanced homodyne interferometers, in which the local oscillators of the corresponding interferometers, have /spl pi//2 phase difference with respect to each other. In this scheme, two identical interferometers for quadrature measurements are constructed by the use of the corresponding polarization components of the signal and local oscillator beams, i.e., principal polarizations of the signal and local oscillator beams are used as independent interferometers. A /spl pi//4 phase shift between the reflected and transmitted polarization components at a polarizing beamsplitter, which was observed in our experiment, was used to provide two local oscillators with /spl pi//2 phase difference. Output interference signals from the corresponding. balanced interferometers, I and Q, respectively, can be written as, I=/spl eta/|E/sub LO/|E/sub s/| cos(/spl Delta//spl phi/),Q=/spl eta/|E/sub LO/|E/sub s/|sin(/spl Delta//spl phi/), where /spl eta/ is the quantum efficiency of photodiode, |E/sub s/| and |E/sub LO/| are the amplitude of signal and local oscillator beam, respectively, and /spl Delta//spl phi/ is the phase difference between signal and local oscillator.