Quantum Theory of Multiport Optical Homodyning

Abstract

Abstract Multiport optical homodyning concerns the combining of a local oscillator with N − 1 signals of the same frequency in a lossless 2N-port junction or an N × N directional coupler. An operator representation is derived for quantum measurements made on these signals in the limit of a strong local oscillator. The local oscillator may otherwise be in an arbitrary quantum state.