Observation and Manipulation of Optical Parametric Downconversion in the Langevin Regime

Yen-Ju Chen; Chun-Yuan Cheng; Tien-Dat Pham; Tzu-An Chen; Chang-Hau Kuo; Yen-Hung Chen; Chih-Sung Chuu

doi:10.1103/mcxn-x7bz

Observation and Manipulation of Optical Parametric Downconversion in the Langevin Regime

Yen-Ju Chen^1,2,*,†, Chun-Yuan Cheng^1,2,*, Tien-Dat Pham ³, Tzu-An Chen^1,2, Chang-Hau Kuo ^1,2, Yen-Hung Chen ^3,4,5, and Chih-Sung Chuu ^1,2,‡

¹Department of Physics and Center for Quantum Science and Technology, National Tsing Hua University, Hsinchu 30013, Taiwan
²National Center for Excellence in Quantum Information Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
³Department of Optics and Photonics, National Central University, Jhongli 320, Taiwan
⁴Quantum Technology Center, College of Science, National Central University, Jhongli 320, Taiwan
⁵Center for Astronautical Physics and Engineering, National Central University, Jhongli 320, Taiwan

^*These authors contributed equally to this work.
^†Contact author: yen-ju.chen@fau.de
^‡Contact author: cschuu@phys.nthu.edu.tw

PDF

Phys. Rev. Lett. 135, 203601 – Published 13 November, 2025

DOI: https://doi.org/10.1103/mcxn-x7bz

Abstract

Quantum fluctuation plays a key role in parametric down-conversion in the Langevin regime. In this Letter, we report the experimental realization of optical parametric down-conversion in the Langevin regime on a chip. By precisely controlling the loss inherently tied to fluctuation, we observe the asymmetric Hong-Ou-Mandel dip—a hallmark of quantum fluctuation in the fluctuation-driven parametric down-conversion (PDC)—and the fluctuation-induced compression of single photons by nearly one order of magnitude. These findings pave the way for the manipulation of quantum fluctuation, quantum states, and system-reservoir interaction.

Physical Review Letters

Export citation

Export citation

Observation and Manipulation of Optical Parametric Downconversion in the Langevin Regime

Abstract

Physics Subject Headings (PhySH)

Authorization Required

Other Options

References (Subscription Required)

Outline

Information

Filter

Filter

Article Lookup

Enter a citation

Observation and Manipulation of Optical Parametric Downconversion in the Langevin Regime

Abstract

Physics Subject Headings (PhySH)

Authorization Required

Log in via your institution

Log in via APS Member Subscription

Other Options

References (Subscription Required)