Measuring the single-photon temporal-spectral wave function

TL;DR

This paper introduces a novel, reference-free method combining ultrafast metrology and spectral detection to rapidly and accurately characterize the temporal-spectral wave function of single photons, crucial for advancing quantum technologies.

Contribution

It presents a new wavelength-tunable technique for single-photon state characterization that does not require an optical reference, enhancing quantum information processing capabilities.

Findings

Enables precise, rapid measurement of single-photon temporal-spectral states.

Operates without the need for an optical reference, simplifying the process.

Supports development of quantum technologies utilizing spectral-temporal modes.

Abstract

Temporal-spectral modes of light provide a fundamental window into the nature of atomic and molecular systems and offer robust means for information encoding. Methods to precisely characterize the temporal-spectral state of light at the single-photon level thus play a central role in understanding quantum emitters and are a key requirement for quantum technologies that harness single-photon states. Here we demonstrate an optical reference-free method, which melds techniques from ultrafast metrology and single-photon spectral detection, to characterize the temporal-spectral state of single photons. This provides a robust, wavelength-tunable approach for rapid characterization of pulsed single-photon states that underpins emerging optical quantum technologies based upon the temporal-spectral mode structure of quantum light.