We demonstrate experimentally a nonunity gain quantum nondemolition measurement based on a simple homodyne measurement and recreation strategy. Although the output state is an amplified version of the input state, the device meets standard criteria for QND measurements: the transfer coefficient was measured to 1.78, and the conditional variance was measured to 0.66.
© 2006 Optical Society of America
Original Manuscript: May 15, 2006
Manuscript Accepted: May 25, 2006
Published: August 9, 2006
Jessica Schneider, Oliver Glöckl, Gerd Leuchs, and Ulrik L. Andersen, "Nonunity gain quantum nondemolition measurements based on measurement and repreparation," Opt. Lett. 31, 2628-2630 (2006)