DATE2026.04.18 #Press Releases

Proposal of time-resolved spectroscopy using quantum entangled photons

Disclaimer: machine translated by DeepL which may contain errors.

An Important Step Toward Time-Resolved Spectroscopy with Highly Selective Excitability

Overview

A joint research team consisting of Project Assistant Professor Yuta Fujihashi and Professor Akihito Ishizaki of the Graduate School of Science, The University of Tokyo, Mr. Ozora Iso, a second-year student in the Master's Program of the Department of Fundamental Science and Technology, Graduate School of Information Science and Technology, and Professor Ryosuke Shimizu of the same Department has proposed a new time-resolved quantum spectroscopy method using quantum entangled photon pairs that can be implemented using existing single photon detection techniques. In this study, we theoretically show that this quantum spectroscopy method has two main advantages.

First, by utilizing the time-frequency correlation of quantum entangled photon pairs, two-dimensional spectral information can be obtained without the need for precise delay control of multiple ultrashort laser pulses, which is required in conventional two-dimensional spectroscopy using classical light. Second, since fluorescence is used for signal detection, it is possible to selectively extract components corresponding to stimulated emission, rather than complex signals containing contributions from multiple nonlinear optical processes, which is often a problem in conventional two-dimensional spectroscopy based on four-wave mixing.

This research result provides a new path for realistically utilizing the advantages of quantum correlation in time-resolved spectroscopy, and is an important step toward the realization of time-resolved spectroscopy with high selective excitability.
The research results will be published online in the American scientific journal Science Advances on April 17, 2026 at 2:00 p.m. EDT.

Conceptual diagram of the time-resolved quantum spectroscopy proposed in this study

Links

The University of Electro-Communications

Publication details

Journal name	Science Advances
Title of paper	Two-dimensional fluorescence spectroscopy with entangled photons and time-and frequency-resolved two-photon coincidence detection
Author(s)	Yuta Fujihashi, Ozora Iso, Ryosuke Shimizu, Akihito Ishizaki
DOI	10.1126/sciadv.aed7026