Precision molecular spectroscopy with a phase-locked terahertz quantum-cascade laser
Journal article, 2025

We demonstrate precision molecular spectroscopy with a phase-locked quantum cascade laser (QCL) over its entire frequency tuning range at 3.4 THz. A Schottky diode harmonic mixer is used to mix the QCL emission with a multiplied microwave signal, referenced to a rubidium frequency standard, to create an intermediate frequency (IF) signal, which is used to phase-lock the QCL. Tuning the frequency of the multiplied microwave reference and keeping the IF fixed allows for precise frequency control of the laser. We identify ten methanol transitions between 3443.5 and 3447.6 GHz and quantify the transition frequencies and broadening parameters with high precision. These measurements are performed without liquid cryogens in a compact setup.

Author

Robert Voigt

German Aerospace Center (DLR)

Martin Wienold

German Aerospace Center (DLR)

Divya Jayasankar

Terahertz and Millimetre Wave Laboratory

Jan Stake

Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory

Xiang Lü

Paul Drude Institut fur Festkorperelektronik

Klaus Biermann

Paul Drude Institut fur Festkorperelektronik

Heinz-Wilhelm Hübers

German Aerospace Center (DLR)

Optics Express

1094-4087 (ISSN) 10944087 (eISSN)

Vol. 33 7 15782-15788

Supraterahertzelektronik för framtida FIR instrument

Swedish National Space Board (2023-00310), 2024-01-01 -- 2027-12-31.

Infrastructure

Kollberg Laboratory

Areas of Advance

Nanoscience and Nanotechnology

Subject Categories (SSIF 2025)

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1364/OE.553739

More information

Latest update

4/2/2025 7