On coupling two phase-coherent frequency-conjugate laser pulses into a microstructure fiber, we observe phase-sensitive photon generation via four-wave mixing, and suppression of Raman emission at the middle frequency.
We present a systematic experimental study of generating correlated photon pairs using a reversed degenerate four-wave mixing process. By overlapping a pair of parallel- (or cross-) polarized laser pump pulses at conjugate frequencies in a microstructure fiber, parallel- or (cross-) polarized correlated photon pairs are generated at the middle frequency. The generation rate of correlated photons by four-wave mixing with parallel-polarized laser pumps in a 1.8 meter microstructure fiber is comparable or higher than that of a parametric down conversion process in a bulk-crystal at similar pump power levels.