Capturing the spectrotemporal structure of a biphoton wave packet with delay-line-anode single-photon imagers

TL;DR

This paper introduces a novel, efficient method using delay-line-anode single-photon imagers to capture the spectrotemporal structure of biphoton wave packets, significantly improving measurement speed and resolution in quantum optics.

Contribution

The study presents a new photon detection technique combining DLDs and spectrometers for rapid, high-resolution joint spectral measurement of biphotons, surpassing conventional methods.

Findings

Achieved faster biphoton spectral measurements (minutes vs. hours)

Demonstrated high-resolution spectrotemporal imaging of biphotons

Enabled efficient coincidence measurements for multi-mode quantum experiments

Abstract

Distinguishing photon-arrival time and position is crucial for advancing quantum technology. However, capturing spatial and temporal information efficiently remains challenging. Here, we present a novel photon-detection technique to achieve a significantly more efficient measurement of frequency-entangled biphoton than conventional photon detectors. We utilize a delay-line-anode single-photon detector (DLD), which consists of a position-sensitive delay line anode sensor behind a microchannel plate. Biphotons are obtained from the decay of biexcitons in the copper chloride semiconductor crystal. Two DLDs are coupled with a grating spectrometer exit to measure the joint spectral distributions of the biphoton. The resulting non-scanning process requires only a few minutes to obtain a temporally and spectrally resolved image, which is much quicker than the conventional biphoton frequency measurement. Our technique paves the way for all experiments in multi-mode quantum science requiring coincidence measurement.