Homodyne detection for pulse-by-pulse squeezing measurements

TL;DR

This paper introduces wideband homodyne detectors capable of pulse-by-pulse squeezing measurements at high repetition rates, advancing the speed and precision of quantum state characterization in continuous-variable quantum optics.

Contribution

The authors develop and demonstrate high-speed, wideband homodyne detectors operating at near-infrared and telecom wavelengths for pulse-by-pulse quantum state measurements.

Findings

Detectors operate effectively at up to 150 MHz repetition rates.

Successfully resolve pulse-by-pulse structure of squeezed states.

Preserve spectral multimode properties of quantum states.

Abstract

Homodyne detection is a phase-sensitive measurement technique, essential for the characterization of continuous-variable (CV)-encoded quantum states of light. It is a key component to the implementation of CV quantum-information protocols and benefits from operating, by design, at room temperature. However, performing high-speed quantum information processing remains a major challenge, as conventional homodyne detectors often fail to sustain pulsed operation at high repetition rates due to electronic limitations. We present wideband homodyne detectors operating at near-infrared (NIR) and telecom wavelengths, with optimized performance at repetition rates up to 150 MHz. We demonstrate their performance by resolving the pulse-by-pulse structure of squeezed states of light at telecom wavelengths while preserving their spectral multimode properties.