Lorenzo Mancini, Pierfrancesco Ulpiani, Chiara Vecchi, Leonardo Daga, Massimiliano Proietti, Carlo Liorni, Massimiliano Dispenza, Francesco Cappelli, Paolo De Natale, Simone Borri, Daniele Palaferri
{"title":"Atto‐Watt Photo‐Detection at Mid‐Infrared Wavelengths by a Room‐Temperature Balanced Heterodyne Set‐Up","authors":"Lorenzo Mancini, Pierfrancesco Ulpiani, Chiara Vecchi, Leonardo Daga, Massimiliano Proietti, Carlo Liorni, Massimiliano Dispenza, Francesco Cappelli, Paolo De Natale, Simone Borri, Daniele Palaferri","doi":"10.1002/lpor.202501339","DOIUrl":null,"url":null,"abstract":"Balanced heterodyne detection (BHD) is a key technology at visible and near‐infrared wavelengths for quantum communication and quantum sensing applications based on coherent read‐out schemes. Extending BHD at mid‐infrared wavelengths (4–11 µm), given the reduced scattering and favourable transparent atmospheric windows, could enable robust earth‐satellite links and few‐photon imaging in high‐noise environments. Currently, quantum applications at these wavelengths are hindered by the lack of high‐sensitivity, room‐temperature photoreceivers; moreover, mid‐infrared single‐photon‐detectors reported to date (superconductors, single‐electron‐transistors, or avalanche‐photodiodes) require cryogenic operation, limiting practicality. Here, a room‐temperature BHD system operating at 4.6 µm‐wavelength with atto‐watt sensitivity level, corresponding to a few tens of photons per second, is demonstrated. This result is obtained by selecting commercially available photodetectors with the highest detectivity and exploiting two heterodyne setups ‐one involving a single quantum‐cascade‐laser (QCL) and an acousto‐optic‐modulator (AOM), and the other one including two QCLs with mutual coherence ensured by a phase‐locked‐loop. Combining a sufficiently high local oscillator (LO) power and the high phase‐coherence between signal and LO is crucial to push the system noise‐equivalent‐power (NEP) to values approaching the shot‐noise‐limit, as confirmed by few‐photons interferometry measurements. This work not only validates viable methods to detect ultra‐low‐intensity signals, but is also potentially scalable to the entire wavelength range already accessible by state‐of‐the‐art mid‐infrared technology.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"10 1","pages":""},"PeriodicalIF":10.0000,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Laser & Photonics Reviews","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1002/lpor.202501339","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 0
Abstract
Balanced heterodyne detection (BHD) is a key technology at visible and near‐infrared wavelengths for quantum communication and quantum sensing applications based on coherent read‐out schemes. Extending BHD at mid‐infrared wavelengths (4–11 µm), given the reduced scattering and favourable transparent atmospheric windows, could enable robust earth‐satellite links and few‐photon imaging in high‐noise environments. Currently, quantum applications at these wavelengths are hindered by the lack of high‐sensitivity, room‐temperature photoreceivers; moreover, mid‐infrared single‐photon‐detectors reported to date (superconductors, single‐electron‐transistors, or avalanche‐photodiodes) require cryogenic operation, limiting practicality. Here, a room‐temperature BHD system operating at 4.6 µm‐wavelength with atto‐watt sensitivity level, corresponding to a few tens of photons per second, is demonstrated. This result is obtained by selecting commercially available photodetectors with the highest detectivity and exploiting two heterodyne setups ‐one involving a single quantum‐cascade‐laser (QCL) and an acousto‐optic‐modulator (AOM), and the other one including two QCLs with mutual coherence ensured by a phase‐locked‐loop. Combining a sufficiently high local oscillator (LO) power and the high phase‐coherence between signal and LO is crucial to push the system noise‐equivalent‐power (NEP) to values approaching the shot‐noise‐limit, as confirmed by few‐photons interferometry measurements. This work not only validates viable methods to detect ultra‐low‐intensity signals, but is also potentially scalable to the entire wavelength range already accessible by state‐of‐the‐art mid‐infrared technology.
期刊介绍:
Laser & Photonics Reviews is a reputable journal that publishes high-quality Reviews, original Research Articles, and Perspectives in the field of photonics and optics. It covers both theoretical and experimental aspects, including recent groundbreaking research, specific advancements, and innovative applications.
As evidence of its impact and recognition, Laser & Photonics Reviews boasts a remarkable 2022 Impact Factor of 11.0, according to the Journal Citation Reports from Clarivate Analytics (2023). Moreover, it holds impressive rankings in the InCites Journal Citation Reports: in 2021, it was ranked 6th out of 101 in the field of Optics, 15th out of 161 in Applied Physics, and 12th out of 69 in Condensed Matter Physics.
The journal uses the ISSN numbers 1863-8880 for print and 1863-8899 for online publications.