RT Journal Article
T1 Sensitivity and noise in THz electro-optic upconversion radiometers
A1 Santamaría Botello, Gabriel Arturo
A1 Popovic, Zoya
A1 Abdalmalak Dawoud, Kerlos Atia
A1 Segovia Vargas, Daniel
A1 Brown, Elliott R.
A1 García Muñoz, Luis Enrique
AB This paper presents a study of noise in room-temperature THz radiometers that use THz-to-optical upconversion followed by optical detection of thermal radiation. Despite some undesired upconverted thermal noise, no noise is intrinsically introduced by efcient electro-optic modulation via a sumfrequency-generation process in high quality factor (Q) whispering-gallery mode (WGM) resonators. However, coherent and incoherent optical detection results in fundamentally diferent noise characteristics. The analysis shows that the upconversion receiver is quantum limited like conventional amplifers and mixers, only when optical homodyne or heterodyne detection is performed. However, this type of receiver shows advantages as a THz photon counter, where counting is in the optical domain. Theoretical predictions show that upconversion-based room-temperature receivers can outperform state-of-the-art cooled and room-temperature THz receivers based on low-noise amplifers and mixers, provided that a photon conversion efciency greater than 1% is realized. Although the detection bandwidth is naturally narrow due to the highly resonant electro-optic modulator, it is not fundamentally limited and can be broadened by engineering selective optical coupling mechanisms to the resonator.
PB Nature Research
SN 2045-2322
YR 2020
FD 2020-06-10
LK https://hdl.handle.net/10016/36413
UL https://hdl.handle.net/10016/36413
LA eng
NO Ministerio de Economía y Competitividad (MINECO) (TEC2013-47753-C3); Comunidad de Madrid MARTINLARA Project (ref. P2018/NMT-4333); FUNDACION SENER; Banco Santander (TEC2016-76997- C3-2-R); 2017 UC3M-Santander Chair of Excellence.
DS e-Archivo
RD 1 sept. 2024