Physical Review Letters
Sub-Poissonian Twin Beams via Competing Nonlinearities
Monika A. M. Marte
Abstract
The interaction of doubly resonant second harmonic generation and nondegenerate down-conversion in a cavity is shown to generate light with excellent noise suppression in two symmetrical dips moving away from zero frequency with increasing pump strength. This feature emerges not only in the amplitude noise of fundamental and second harmonic, but also in the single beam and the sum intensity fluctuation spectra of the twin beams produced by down-conversion, which makes this system a potentially useful source for quantum cryptography or optical quantum correlation experiments.