Direct measurement of the Wigner function by photon counting

K. Banaszek, C. Radzewicz, K. Wodkiewicz, J. S. Krasinski

Published 1999-03-08Version 1

We report a direct measurement of the Wigner function characterizing the quantum state of a light mode. The experimental scheme is based on the representation of the Wigner function as an expectation value of a displaced photon number parity operator. This allowed us to scan the phase space point-by-point, and obtain the complete Wigner function without using any numerical reconstruction algorithms.