Abstract
The terahertz range of the electromagnetic spectrum reveals important insights when studying material properties. An ultra‐broadband terahertz time‐domain spectroscopy system based on state‐of‐the‐art, high‐stability organic nonlinear optical crystals used as both THz wave generator and detector is presented. In transmission geometry, a broad spectrum exceeding 20 THz and a high dynamic range of more than 80 dB is achieved using a compact 100 MHz femtosecond laser working at telecom wavelength 1560 nm. In the normal‐incidence reflection geometry, a similar bandwidth with a dynamic range surpassing 60 dB is reported. The experimental results are supported by a complete theoretical model, which includes the pump pulse duration, THz phonon/vibrational modes of the organic crystals and optical/THz beam path optimizations. The effectiveness of the newly developed system is demonstrated by measuring pharmaceutical samples with distinct THz features in the ultra‐broadband THz range and by measuring narrow water vapor lines at a spectral resolution of 2.7 GHz (0.090 cm−1), resulting in an excellent accuracy with a frequency deviation of less than 0.05% from the reference values.
Highlights
Introduction when studying material propertiesAn ultra-broadband terahertz time-domain spectroscopy system based on state-of-the-art, high-stability organic nonlinear optical crystals used as both THz wave generator and detector is presented
We discuss the various parameters of our THz time-domain spectroscopy (THz TDS) system that limit the final bandwidth. These include the pulse width of the pump femtosecond laser pulses, THz phonon and vibrational modes of the organic crystals used for THz generation and detection, and the propagation losses due to specific THz and optical components in the system
In this work we developed an ultra-broadband and high-dynamicrange THz TDS system based on organic nonlinear optical (NLO) crystals used for both generation and detection of THz waves
Summary
An ultra-broadband terahertz time-domain spectroscopy system based on state-of-the-art, high-stability organic nonlinear optical crystals used as both THz wave generator and detector is presented. Over the past few decades, the generation and detection of broadband terahertz waves in the frequency range 0.1–30 THz have seen tremendous progress, both in the achievable bandwidths and in the generated THz intensities.[1,2] Most of the laser working at telecom wavelength 1560 nm. Pulsed broadband THz sources are widely used in today’s THz time-domain spectroscopy (THz TDS) systems. For such systems, two main principles of THz wave generation are commonly used: photoconductive antennas[3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
