--- _id: '22' abstract: - lang: eng text: Conventional ultra-high sensitivity detectors in the millimeter-wave range are usually cooled as their own thermal noise at room temperature would mask the weak received radiation. The need for cryogenic systems increases the cost and complexity of the instruments, hindering the development of, among others, airborne and space applications. In this work, the nonlinear parametric upconversion of millimeter-wave radiation to the optical domain inside high-quality (Q) lithium niobate whispering-gallery mode (WGM) resonators is proposed for ultra-low noise detection. We experimentally demonstrate coherent upconversion of millimeter-wave signals to a 1550 nm telecom carrier, with a photon conversion efficiency surpassing the state-of-the-art by 2 orders of magnitude. Moreover, a theoretical model shows that the thermal equilibrium of counterpropagating WGMs is broken by overcoupling the millimeter-wave WGM, effectively cooling the upconverted mode and allowing ultra-low noise detection. By theoretically estimating the sensitivity of a correlation radiometer based on the presented scheme, it is found that room-temperature radiometers with better sensitivity than state-of-the-art high-electron-mobility transistor (HEMT)-based radiometers can be designed. This detection paradigm can be used to develop room-temperature instrumentation for radio astronomy, earth observation, planetary missions, and imaging systems. article_processing_charge: No article_type: original author: - first_name: Gabriel full_name: Botello, Gabriel last_name: Botello - first_name: Florian full_name: Sedlmeir, Florian last_name: Sedlmeir - first_name: Alfredo R full_name: Rueda Sanchez, Alfredo R id: 3B82B0F8-F248-11E8-B48F-1D18A9856A87 last_name: Rueda Sanchez orcid: 0000-0001-6249-5860 - first_name: Kerlos full_name: Abdalmalak, Kerlos last_name: Abdalmalak - first_name: Elliott full_name: Brown, Elliott last_name: Brown - first_name: Gerd full_name: Leuchs, Gerd last_name: Leuchs - first_name: Sascha full_name: Preu, Sascha last_name: Preu - first_name: Daniel full_name: Segovia Vargas, Daniel last_name: Segovia Vargas - first_name: Dmitry full_name: Strekalov, Dmitry last_name: Strekalov - first_name: Luis full_name: Munoz, Luis last_name: Munoz - first_name: Harald full_name: Schwefel, Harald last_name: Schwefel citation: ama: Botello G, Sedlmeir F, Rueda Sanchez AR, et al. Sensitivity limits of millimeter-wave photonic radiometers based on efficient electro-optic upconverters. Optica. 2018;5(10):1210-1219. doi:10.1364/OPTICA.5.001210 apa: Botello, G., Sedlmeir, F., Rueda Sanchez, A. R., Abdalmalak, K., Brown, E., Leuchs, G., … Schwefel, H. (2018). Sensitivity limits of millimeter-wave photonic radiometers based on efficient electro-optic upconverters. Optica. https://doi.org/10.1364/OPTICA.5.001210 chicago: Botello, Gabriel, Florian Sedlmeir, Alfredo R Rueda Sanchez, Kerlos Abdalmalak, Elliott Brown, Gerd Leuchs, Sascha Preu, et al. “Sensitivity Limits of Millimeter-Wave Photonic Radiometers Based on Efficient Electro-Optic Upconverters.” Optica, 2018. https://doi.org/10.1364/OPTICA.5.001210. ieee: G. Botello et al., “Sensitivity limits of millimeter-wave photonic radiometers based on efficient electro-optic upconverters,” Optica, vol. 5, no. 10. pp. 1210–1219, 2018. ista: Botello G, Sedlmeir F, Rueda Sanchez AR, Abdalmalak K, Brown E, Leuchs G, Preu S, Segovia Vargas D, Strekalov D, Munoz L, Schwefel H. 2018. Sensitivity limits of millimeter-wave photonic radiometers based on efficient electro-optic upconverters. Optica. 5(10), 1210–1219. mla: Botello, Gabriel, et al. “Sensitivity Limits of Millimeter-Wave Photonic Radiometers Based on Efficient Electro-Optic Upconverters.” Optica, vol. 5, no. 10, 2018, pp. 1210–19, doi:10.1364/OPTICA.5.001210. short: G. Botello, F. Sedlmeir, A.R. Rueda Sanchez, K. Abdalmalak, E. Brown, G. Leuchs, S. Preu, D. Segovia Vargas, D. Strekalov, L. Munoz, H. Schwefel, Optica 5 (2018) 1210–1219. date_created: 2018-12-11T11:44:12Z date_published: 2018-10-20T00:00:00Z date_updated: 2023-10-17T12:12:40Z day: '20' department: - _id: JoFi doi: 10.1364/OPTICA.5.001210 external_id: isi: - '000447853100007' intvolume: ' 5' isi: 1 issue: '10' language: - iso: eng main_file_link: - open_access: '1' url: 'www.doi.org/10.1364/OPTICA.5.001210 ' month: '10' oa: 1 oa_version: Published Version page: 1210 - 1219 publication: Optica publication_identifier: issn: - '23342536' publication_status: published publist_id: '8033' quality_controlled: '1' scopus_import: '1' status: public title: Sensitivity limits of millimeter-wave photonic radiometers based on efficient electro-optic upconverters type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 5 year: '2018' ...