Demonstration of low-noise frequency conversion by bragg scattering in a fiber

We experimentally examine the noise properties of a two-pump optical parametric amplifier when converting frequencies using the Bragg-scattering (BS) and phase-conjugation (PC) processes. Using co-polarized pumps and signal, we show that the noise performance is limited by spontaneous Raman scattering. The noise performance of BS is superior to that of PC, and should improve with larger frequency excursions.