Terahertz frequency counter based on a semiconductor-superlattice harmonic mixer with four-octave measurable bandwidth and 16-digit precision. (19th July 2021)

• Record Type: Journal Article
• Authors: Nagano, Shigeo; Kumagai, Motohiro; Ito, Hiroyuki; Hanado, Yuko; Ido, Tetsuya
• Is Part Of: Metrologia. Volume 58:Number 5(2021)
• Publication Date: 2021-07-19
• Subjects: frequency measurement -- terahertz frequency standard -- semiconductor superlattice; Weights and measures -- Periodicals; Weights and Measures -- Periodicals; 530.805
• DOI: 10.1088/1681-7575/ac0712
• Languages: English
• ISSNs: 0026-1394

Abstract

Abstract: We have developed a broadband and high-precision terahertz (THz) frequency counter based on a semiconductor-superlattice harmonic mixer (SLHM). Comparison of two THz frequencies determined using two independent counters and direct measurement of frequency-stabilized THz-quantum cascade lasers by a single counter showed a measurement uncertainty of less than 1 × 10 −16 over a four-octave range from 120 GHz to 2.8 THz. Further extension of this measurable range was indicated by the research regarding the higher-harmonics generation of a local oscillator for the SLHM. This compact and easy-to-handle THz counter operating at room temperature is available for high-resolution spectroscopy of ultracold molecules proposed for detecting temporal changes in physics constants as well as many THz applications requiring a wide measurement range without a bulky cryogenic apparatus.