Enhancement of single-photon level signal detection based on phase sensitive amplification strategy

Abstract

We investigate the ability of phase-sensitive amplification (PSA) to noiselessly amplify the preferred quadrature components of single-photonsignals that are limited by phase fluctuations relative to the pump. We presenta PSA enhancement strategy that is more realistic for possible experimentalrealization and is expected to significantly improve the detection of weaksignals at the single-photon level and obtain more useful information. Our studyshows that with a large PSA gain, proper transmissivity allows both direct and
balanced homodyne detections to operate optimally simultaneously, and effectively improves the noise figure degradation owing to the internal losses and non-ideal detection efficiency.