Open AccessHigh-speed broadband frequency sweep of continuous-wave terahertz radiation
Author(s) -
Dae-Su Yee,
J. S. Yahng,
Choon-Su Park,
Hwi Don Lee,
Chang-Seok Kim
Publication year - 2015
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.014806
Subject(s) - terahertz radiation , optics , photomixing , sweep frequency response analysis , laser , broadband , materials science , continuous wave , terahertz spectroscopy and technology , far infrared laser , optoelectronics , physics , acoustics , terahertz metamaterials
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.