Compact terahertz multiheterodyne spectroscopy using a Y-shape dual-comb configuration
Year: 2019
Type: preprint
Abstract: Due to the fast and high resolution characteristics, the dual-combspectroscopy attracts more and more interest since the first demonstration. In
the terahertz frequency range where abundant absorption lines (finger-prints)
of molecules are located, the multiheterodyne spectroscopy employing the
dual-comb technique shows an advantage in real-time spectral detection over the
traditional Fourier transform infrared or time domain spectroscopies. Here, we
demonstrate the first compact terahertz multiheterodyne spectroscopy using a
Y-shape dual-comb configuration without a need of additional fast detectors.
With only $\sim$270 nW terahertz power coupled into a terahertz QCL comb (no
optics for alignment), the down-converted dual-comb spectra are successfully
obtained at different carrier frequencies. To prove the spectroscopic ability,
we further demonstrate that the compact dual-comb system can be used to
calibrate the relative humidity in the air and to measure the transmission of a
GaAs etalon. Due to the small optical coupling aperture (150 $\mu$m), it is
also potential to use the dual-comb technique for terahertz imaging.
Source: arXiv (Cornell University)
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3180119060