Room Temperature Terahertz Spectrometer with Quantum-Level Sensitivity

Abstract

Photon detection with quantum-level sensitivity is particularly challenging in the terahertz regime (0.1-10 THz), which contains ~98% of all the photons existing in the universe. Near-quantum-limited terahertz spectrometry has so far only been possible through the use of cryogenically cooled superconducting mixers as frequency downconverters. Here we introduce a spectrometry scheme that uses plasmonic photomixing for frequency downconversion to offer quantum-level sensitivities at room temperature for the first time. Frequency downconversion is achieved by mixing terahertz radiation and a heterodyning optical beam with a terahertz beat frequency in a plasmonics-enhanced semiconductor active region. We demonstrate spectrometer sensitivities down to 3 times the quantum-limit at room temperature. With a versatile design capable of broadband spectrometry, this plasmonic photomixer has broad applicability to quantum optics, chemical sensing, biological studies, medical diagnosis, high data-rate communication, as well as astronomy and atmospheric studies.

arXiv comment17 pages, 7 figures

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Cited by in corpus (8)

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• Plasmonic Heterodyne Spectrometry for Resolving the Spectral Signatures of Ammonia over a 1-5 THz Frequency Range
• Toward a large bandwidth photonic correlator for infrared heterodyne interferometry
• Response to 'Room Temperature, Quantum-Limited THz Heterodyne Detection? Not Yet'
• Room Temperature, Quantum-Limited THz Heterodyne Detection? Not Yet