Terahertz Frequency Comb High-Resolution Heterodyne Spectrometer

TL;DR

This paper presents a novel terahertz frequency comb spectrometer that achieves high-resolution, rapid, and simultaneous measurement of multiple spectral lines over a broad bandwidth, advancing THz spectroscopy capabilities.

Contribution

It introduces a new heterodyne spectrometer setup combining THz frequency combs with fast Fourier detection for high-resolution, wide-band THz spectroscopy.

Findings

Measured over 150 methanol lines at 723 GHz

Achieved 70 kHz spectral resolution

Recorded a spectrum in under 20 minutes

Abstract

We demonstrate the advantages of THz frequency combs for high-resolution spectroscopy. This benefits from wide spectral coverage and the exact knowledge of the frequency position of each comb component. Heterodyne detection combined with a fast Fourier spectrometer enables rapid and simultaneous measurement of more than 80 frequency comb modes covering a 7.5 GHz bandwidth. A spectrum is obtained in under 20 minutes yielding a uniform resolution of 70 kHz. This new setup has been validated by recording more than 150 lines of methanol around 723 GHz, and represents a new solution to exploit THz frequency combs for high-resolution spectroscopy.