Compact non-linear interferometer with ultrahigh sensitivity

摘要

A compact interferometer is described which has an ultrahigh sensitivity response to small linear displacement or optical pathlength changes in general. The high sensitivity is achieved by rotating the orthogonally polarised heterodyne input states through angle R, and therefore deliberately frequency mixing the heterodyne components in a specific format in both arms of a polarising interferometer. In an additional treatment, the sensitivity is further enhanced by mixing the orthogonally polarised output beam into a given ratio in the polariser-analyser placed in front of the measurement photodetector.