Related Experiment Video
Updated: Apr 10, 2026

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis
Published on: September 22, 2017
High-speed broadband frequency sweep of continuous-wave terahertz radiation
Abstract:
We present a new technical implementation of a high-speed broadband frequency sweep of continuous-wave terahertz (THz) radiation. THz frequency sweeping with a kHz sweep rate and a THz sweep range is implemented using THz photomixing in which an optical beat source consists of a wavelength-swept laser and a distributed feedback laser diode. During the frequency sweep, frequency-domain THz interferograms are measured using the coherent homodyne detection employing signal averaging for noise reduction, which can give time-of-flight information via fast Fourier transform. Multiple reflections in a Si wafer and the thickness of the wafer are measured to demonstrate the potential of this method for fast THz tomography and thickness measurement.
Related Concept Videos
Propagation Speed of Electromagnetic Waves
NMR Spectrometers: Overview
IR Frequency Region: X–H Stretching
Continuous -time Fourier Transform
Generating Electromagnetic Radiations
Bandpass Sampling
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....

