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-photon signals that are limited by phase fluctuations relative to the pump. We present a PSA enhancement strategy that is more realistic for possible experimental realization and is expected to significantly improve the detection of weak signals at the single-photon level and obtain more useful information. Our study shows 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.

Keywords

• phase sensitive
• signal amplification
• accurate measurement
• phase fluctuation