Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber Interferometer

In the realm of quantum communication and photonic technologies, the extension of coherence time for photon wave packets is essential for improving system efficacy. This research introduces a methodology for measuring coherence time utilizing an unbalanced fiber interferometer, specifically designed...

Full description

Saved in:
Bibliographic Details
Main Authors: Ya Li, Wanru Wang, Qizhou Wu, Youxing Chen, Can Sun, Hai Wang, Weizhe Qiao
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Photonics
Subjects:
Online Access:https://www.mdpi.com/2304-6732/12/5/415
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850256717275725824
author Ya Li
Wanru Wang
Qizhou Wu
Youxing Chen
Can Sun
Hai Wang
Weizhe Qiao
author_facet Ya Li
Wanru Wang
Qizhou Wu
Youxing Chen
Can Sun
Hai Wang
Weizhe Qiao
author_sort Ya Li
collection DOAJ
description In the realm of quantum communication and photonic technologies, the extension of coherence time for photon wave packets is essential for improving system efficacy. This research introduces a methodology for measuring coherence time utilizing an unbalanced fiber interferometer, specifically designed for tunable pulse-width photon wave packets produced by cold atoms. By synchronously generating write pulses, signal light, and frequency-locking light from a single laser source, the study effectively mitigated frequency discrepancies that typically arise from the use of multiple light sources. The implementation of frequency-resolved photon counting under phase-locked conditions was accomplished through the application of polarization filtering and cascaded filtering techniques. The experimental results indicated that the periodicity of frequency shifts in interference fringe patterns diminishes as the differences in delay arm lengths increase, while fluctuations in fiber length and high-frequency laser jitter adversely affect interference visibility. Through an analysis of the correlation between delay and photon counts, the coherence time of the write laser was determined to be 2.56 µs, whereas the Stokes photons produced through interactions with cold atoms exhibited a reduced coherence time of 1.23 µs. The findings suggest that enhancements in laser bandwidth compression and fiber phase stability could further prolong the coherence time of photon wave packets generated by cold atoms, thereby providing valuable technical support for high-fidelity quantum information processing.
format Article
id doaj-art-40aa43e48bc44f359f66f990f49e6842
institution OA Journals
issn 2304-6732
language English
publishDate 2025-04-01
publisher MDPI AG
record_format Article
series Photonics
spelling doaj-art-40aa43e48bc44f359f66f990f49e68422025-08-20T01:56:35ZengMDPI AGPhotonics2304-67322025-04-0112541510.3390/photonics12050415Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber InterferometerYa Li0Wanru Wang1Qizhou Wu2Youxing Chen3Can Sun4Hai Wang5Weizhe Qiao6School of Information and Communication Engineering, North University of China, Taiyuan 030051, ChinaSchool of Information and Communication Engineering, North University of China, Taiyuan 030051, ChinaSchool of Information and Communication Engineering, North University of China, Taiyuan 030051, ChinaSchool of Information and Communication Engineering, North University of China, Taiyuan 030051, ChinaThe State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, ChinaThe State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, ChinaShanxi Dazhong Electronic Information Industry Group Co., Ltd., Taiyuan 030024, ChinaIn the realm of quantum communication and photonic technologies, the extension of coherence time for photon wave packets is essential for improving system efficacy. This research introduces a methodology for measuring coherence time utilizing an unbalanced fiber interferometer, specifically designed for tunable pulse-width photon wave packets produced by cold atoms. By synchronously generating write pulses, signal light, and frequency-locking light from a single laser source, the study effectively mitigated frequency discrepancies that typically arise from the use of multiple light sources. The implementation of frequency-resolved photon counting under phase-locked conditions was accomplished through the application of polarization filtering and cascaded filtering techniques. The experimental results indicated that the periodicity of frequency shifts in interference fringe patterns diminishes as the differences in delay arm lengths increase, while fluctuations in fiber length and high-frequency laser jitter adversely affect interference visibility. Through an analysis of the correlation between delay and photon counts, the coherence time of the write laser was determined to be 2.56 µs, whereas the Stokes photons produced through interactions with cold atoms exhibited a reduced coherence time of 1.23 µs. The findings suggest that enhancements in laser bandwidth compression and fiber phase stability could further prolong the coherence time of photon wave packets generated by cold atoms, thereby providing valuable technical support for high-fidelity quantum information processing.https://www.mdpi.com/2304-6732/12/5/415coherence timeinterference visibilityunbalanced fiber interferometer
spellingShingle Ya Li
Wanru Wang
Qizhou Wu
Youxing Chen
Can Sun
Hai Wang
Weizhe Qiao
Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber Interferometer
Photonics
coherence time
interference visibility
unbalanced fiber interferometer
title Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber Interferometer
title_full Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber Interferometer
title_fullStr Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber Interferometer
title_full_unstemmed Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber Interferometer
title_short Measurement of Coherence Time in Cold Atom-Generated Tunable Photon Wave Packets Using an Unbalanced Fiber Interferometer
title_sort measurement of coherence time in cold atom generated tunable photon wave packets using an unbalanced fiber interferometer
topic coherence time
interference visibility
unbalanced fiber interferometer
url https://www.mdpi.com/2304-6732/12/5/415
work_keys_str_mv AT yali measurementofcoherencetimeincoldatomgeneratedtunablephotonwavepacketsusinganunbalancedfiberinterferometer
AT wanruwang measurementofcoherencetimeincoldatomgeneratedtunablephotonwavepacketsusinganunbalancedfiberinterferometer
AT qizhouwu measurementofcoherencetimeincoldatomgeneratedtunablephotonwavepacketsusinganunbalancedfiberinterferometer
AT youxingchen measurementofcoherencetimeincoldatomgeneratedtunablephotonwavepacketsusinganunbalancedfiberinterferometer
AT cansun measurementofcoherencetimeincoldatomgeneratedtunablephotonwavepacketsusinganunbalancedfiberinterferometer
AT haiwang measurementofcoherencetimeincoldatomgeneratedtunablephotonwavepacketsusinganunbalancedfiberinterferometer
AT weizheqiao measurementofcoherencetimeincoldatomgeneratedtunablephotonwavepacketsusinganunbalancedfiberinterferometer