Measuring quantum state overlaps of traveling optical fields

Research paper by J. Clausen, M. Dakna, L. Knoll, D. -G. Welsch

Indexed on: 07 Oct '99Published on: 07 Oct '99Published in: Quantum Physics


We propose a detection scheme for measuring the overlap of the quantum state of a weakly excited traveling-field mode with a desired reference quantum state, by successive mixing the signal mode with modes prepared in coherent states and performing photon-number measurements in an array of beam splitters. To illustrate the scheme, we discuss the measurement of the quantum phase and the detection of Schrodinger-cat-like states.