Dynamic range and numerical error propagation in terahertz time-domain spectroscopy

2005 ◽  
Author(s):  
Bernd M. Fischer ◽  
Matthias Hoffmann ◽  
Peter Uhd Jepsen
Keyword(s):  
Time Domain ◽  
Error Propagation ◽  
Dynamic Range ◽  
Numerical Error ◽  
Terahertz Time Domain Spectroscopy ◽  
Time Domain Spectroscopy

scholarly journals Terahertz Time-Domain Spectroscopy Based on Commercially Available 1550 nm Fabry–Perot Laser Diode and ErAs:In(Al)GaAs Photoconductors

2019 ◽  
Vol 9 (13) ◽  
pp. 2704 ◽  
Author(s):  
Kai-Henning Tybussek ◽  
Kevin Kolpatzeck ◽  
Fahd Faridi ◽  
Sascha Preu ◽  
Jan C. Balzer
Keyword(s):  
Laser Diode ◽  
Time Domain ◽  
Dynamic Range ◽  
Laser System ◽  
Industrial Applications ◽  
Thz Radiation ◽  
Full Potential ◽  
Terahertz Time Domain Spectroscopy ◽  
Time Domain Spectroscopy ◽  
Fabry Perot

THz time-domain spectroscopy (TDS) is a promising tool for quality control purposes in industrial applications, but the high cost and the relatively large laser sources still make it difficult to use the full potential of the technology for a decent price. In this work, a THz TDS system, which uses a commercially available Fabry–Perot laser diode emitting at 1550 nm, is presented. By dispersion compensation, pulses with a duration of 544 fs were generated, resulting in THz radiation with a bandwidth of 1.4 THz and a peak dynamic range of 56 dB with state-of-the-art ErAs:In(Al)GaAs photoconducting antennas. These results are compared with those of a conventional and expensive fiber laser system with a 90 fs pulse duration.

scholarly journals Ultra-High Repetition Rate Terahertz Time-Domain Spectroscopy for Micrometer Layer Thickness Measurement

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5389
Author(s):  
Kevin Kolpatzeck ◽  
Xuan Liu ◽  
Lars Häring ◽  
Jan C. Balzer ◽  
Andreas Czylwik
Keyword(s):  
Time Domain ◽  
Repetition Rate ◽  
Dynamic Range ◽  
Reference Signal ◽  
Thickness Measurement ◽  
Optical Signal ◽  
High Repetition Rate ◽  
Terahertz Time Domain Spectroscopy ◽  
Time Domain Spectroscopy ◽  
High Repetition

Terahertz time-domain spectroscopy systems driven by monolithic mode-locked laser diodes (MLLDs) exhibit bandwidths exceeding 1 THz and a peak dynamic range that can compete with other state-of-the-art systems. Their main difference compared to fiber-laser-driven systems is their ultra-high repetition rate of typically dozens of GHz. This makes them interesting for applications where the length of the terahertz path may not be precisely known and it enables the use of a very short and potentially fast optical delay unit. However, the phase accuracy of the system is limited by the accuracy with which the delay axes of subsequent measurements are synchronized. In this work, we utilize an all-fiber approach that uses the optical signal from the MLLD in a Mach–Zehnder interferometer to generate a reference signal that we use to synchronize the detected terahertz signals. We demonstrate transmission-mode thickness measurements of stacked layers of 17μm thick low-density polyethylene (LDPE) films.

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