Ultra-fast, High-Bandwidth Coherent cw THz Spectrometer for Non-destructive Testing

Continuous wave THz (cw THz) systems define the state-of-the-art in terms of spectral resolution in THz spectroscopy. Hitherto, acquisition of broadband spectra in a cw THz system was always connected with slow operation. Therefore, high update rate applications like inline process monitoring and no...

Full description

Saved in:
Bibliographic Details
Published inJournal of infrared, millimeter and terahertz waves Vol. 40; no. 3; pp. 288 - 296
Main Authors Liebermeister, Lars, Nellen, Simon, Kohlhaas, Robert, Breuer, Steffen, Schell, Martin, Globisch, Björn
Format Journal Article
LanguageEnglish
Published New York Springer US 15.03.2019
Springer Nature B.V
Subjects
Broadband
Classical Electrodynamics
Continuous radiation
Destructive testing
Electrical Engineering
Electronics and Microelectronics
Engineering
Instrumentation
Nondestructive testing
Spectra
Spectral resolution
Spectroscopy
Spectrum analysis
State of the art
Upgrading
High update rate
Continuous wave
Broadband
THz
Terahertz
Non-destructive testing
Spectrometer
NDT
Online AccessGet full text

Cover

More Information
Summary:Continuous wave THz (cw THz) systems define the state-of-the-art in terms of spectral resolution in THz spectroscopy. Hitherto, acquisition of broadband spectra in a cw THz system was always connected with slow operation. Therefore, high update rate applications like inline process monitoring and non-destructive testing are served by time domain spectroscopy (TDS) systems. However, no fundamental restriction prevents cw THz technology from achieving faster update rates and be competitive in this field. In this paper, we present a fully fiber-coupled cw THz spectrometer. Its sweep speed is two orders of magnitude higher compared to commercial state-of-the-art systems and reaches a record performance of 24 spectra per second with a bandwidth of more than 2 THz. In the single-shot mode, the same system reaches a peak dynamic range of 67 dB and exceeds a value of 100 dB with averaging of 7 min, which is among the highest values ever reported. The frequency steps can be as low as 40 MHz. Due to the fully homodyne detection, each spectrum contains full amplitude and phase information. This demonstration of THz-spectroscopy at video-rate is an essential step towards applying cw THz systems in non-destructive, in line testing.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
ISSN:1866-6892
1866-6906
DOI:10.1007/s10762-018-0563-6