Experimental observation of three-color optical quantum correlations
Katiúscia N. Cassemiro, Alessandro S. Villar, Paulo Valente, Marcelo Martinelli, P. Nussenzveig · Optics Letters · 2007
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.