Abstract

In two recent papers,^1,2 it was shown how the interaction of a two-level atom with a standing laser field allows for a QND measurement of the atomic position using a quadrature component of the laser field as a meter. Here we demonstrate a complementary scheme in which a quadrature component of a propagating laser wave acts as the meter for a QND measurement of the atomic momentum. The measurement is based on a detectable phase shift of the cavity mode that results from the atom-field interaction. The principal characteristics of the measurement scheme are presented. We demonstrate how a selective version of the measurement scheme may be used to tailor an atomic wave function and to turn the measurement scheme into a "virtual beam handler."

© 1992 Optical Society of America