Single-shot high-resolution spectroscopy of single-photon-level optical pulses using a virtually imaged phased-array and single-photon avalanche diode array

TL;DR

This paper presents a novel single-shot high-resolution spectroscopy system for single-photon-level pulses, combining a VIPA for frequency-to-spatial mode mapping and a SPAD array for detection, with potential applications in quantum repeaters.

Contribution

The study introduces an integrated spectroscopy system that achieves high-resolution, single-shot measurements at the single-photon level, tailored for quantum memory applications.

Findings

Demonstrated system with weak coherent pulses at 120 MHz mode interval

Matched the system's resolution to atomic frequency comb quantum memory requirements

Enhanced potential for frequency multiplexing in quantum repeater schemes

Abstract

Single-shot high-resolution spectroscopy at the single-photon-level has emerged as a promising measurement technique, enabling novel observations and evaluations that were previously challenging. This technology is particularly effective for spectroscopic applications aimed at realizing frequency-multiplexed quantum repeaters. In this study, we propose a single-shot high-resolution single-photon spectroscopy system that integrates high-resolution frequency-to-spatial mode mapping using a virtually imaged phased-array (VIPA) and high-precision spatial mode detection using a single-photon avalanche diode (SPAD) array. We experimentally demonstrated the principle of this system using weak coherent pulses with a frequency mode interval of 120 MHz. This interval closely matches the minimum frequency mode spacing of the atomic frequency comb quantum memory with the Pr$^{3+}$-ion-doped Y$_2$SiO$_5$ crystal. By applying the proposed system, we expect to maximize the multiplexing capability of frequency-multiplexed quantum repeater schemes utilizing such quantum memories.