In this paper, the noise performances of 1.5 um correlated photon pair
generations based on spontaneous four wave-mixing in three types of fibers,
i.e., dispersion shifted fiber, highly nonlinear fiber, and highly nonlinear
microstructure fiber are investigated experimentally. Result of the comparison
shows that highly nonlinear microstructure fiber has the lowest Raman noise
photon generation rate among the three types of fibers while correlated photon
pair generation rate is the same. Theoretical analysis shows that the noise
performance is determined by the nonlinear index and Raman response of the
material in fiber core. The Raman response raises with increasing doping level,
however, the nonlinear index is almost unchanged with it. As a result, highly
nonlinear microstructure fiber with pure silica core has the best noise
performance and has great potential in practical sources of correlated photon
pairs and heralded single photons.Comment: 10 pages, 6 figure