title: Experimental observation of three-color optical quantum correlations.
abstract: 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.
authors.affiliation: Instituto de Física, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Katiúscia N
authors.initials: KN
authors.lastname: Cassemiro
authors.forename: Alessandro S
authors.initials: AS
authors.lastname: Villar
authors.forename: Paulo
authors.initials: P
authors.lastname: Valente
authors.forename: Marcelo
authors.initials: M
authors.lastname: Martinelli
authors.forename: Paulo
authors.initials: P
authors.lastname: Nussenzveig