Quantum correlations among bright pump, signal, and idler beams produced by an optical parametric oscillator, all with different frequencies, are experimentally demonstrated. We show that the degree of entanglement between signal and idler fields is improved by using information on pump fluctuations. To our knowledge this is the first observation of three-color optical quantum correlations.
© 2007 Optical Society of America
Original Manuscript: October 23, 2006
Revised Manuscript: December 6, 2006
Manuscript Accepted: December 13, 2006
Published: February 15, 2007
Katiúscia N. Cassemiro, Alessandro S. Villar, Paulo Valente, Marcelo Martinelli, and Paulo Nussenzveig, "Experimental observation of three-color optical quantum correlations," Opt. Lett. 32, 695-697 (2007)