The Interferometer as an Optical Network

Abstract

We consider a generic interferometric set-up as a device to record interference fringes. The system is characterized by two variable transmission beam-splitters. A coherent signal is measured and its noise properties are manipulated by mixing in a squeezed vacuum through the second input port. The performance is optimized either by minimizing the noise at the dark and the light fringes, or alternatively by keeping it below the standard quantum limit for all phase angles observed. The analysis is carried out using a quantum optical network formalism generalizing the classical Jones calculus. The results obtained are interpreted and explained using the Wigner function for the output signals.