Efficient ultrafast homodyne detection of quantum light

TL;DR

This paper introduces an optimized method for ultrafast homodyne detection of quantum light, significantly improving signal-to-noise ratio and detection efficiency through tailored temporal weighting.

Contribution

It presents a novel approach that exploits temporal correlations and optimizes signal processing to enhance ultrafast quantum light detection efficiency.

Findings

Increased signal-to-noise ratio in ultrafast homodyne detection.

Enhanced squeezing and anti-squeezing levels observed experimentally.

Optimal temporal weight derived by solving a generalized Rayleigh quotient.

Abstract

Ultrafast continuous-variable quantum states offer new opportunities for advanced quantum technologies, but efficient homodyne detection of these states remains challenging. Here, we present a method for efficient ultrafast homodyne detection by exploiting temporal correlations in detector signals. By optimizing the temporal weight used to extract quadrature outcomes, we achieve a substantial increase in the signal-to-noise ratio of ultrafast homodyne detection, thereby improving the detection efficiency. We analyze the autocorrelations of shot noise and electronic noise and determine the optimal weight by solving a generalized Rayleigh quotient problem. The optimal weight enhances the squeezing and anti-squeezing levels observed experimentally. These results highlight the importance of optimized signal processing for efficient quantum measurements.