Waveguide terahertz time-domain spectroscopy of nanometer water layers.

Parallel-Plate Waveguide Terahertz Time Domain Spectroscopy for Ultrathin Conductive Films

Development of techniques for characterization of extremely thin films is an important challenge in terahertz (THz) science and applications. Spectroscopic measurements of materials on the nanometer scale or of atomic layer thickness (2D materials) require a sufficient terahertz wave–matter interaction length, which is challenging to achieve in conventional transmission geometry. Waveguide-base...

High Resolution Waveguide Terahertz Time-Domain Spectroscopy

Terahertz time-domain spectroscopy accesses the frequency range between 100 GHz and 5 THz by using the coherent generation and detection based on femtosecond laser sources. On the way to obtain fingerprint absorption spectra of molecular solids, terahertz waveguides have proven to be a valuable tool to extend the results to narrow and high resolution linewidths of crystalline solids. We will di...

Liquids and molecular solids investigated by THz time-domain reflection and parallel-plate waveguide spectroscopy

Narrow-line waveguide terahertz time-domain spectroscopy of aspirin and aspirin precursors.

Low frequency vibrational modes of pharmaceutical molecules are dependent on the molecule as a whole and can be used for identification purposes. However, conventional Fourier transform far-infrared spectroscopy (FT-IR) and terahertz time-domain spectroscopy (THz-TDS) often result in broad, overlapping features that are difficult to distinguish. The technique of waveguide THz-TDS has been recen...

Temperature dependent characterization of terahertz vibrations of explosives and related threat materials.

Waveguide terahertz time-domain spectroscopy (THz-TDS) is used to characterize the temperature dependent vibrational properties of three threat-related materials: 4-amino-dinitrotoluene (4A-DNT), pentaerythritol tetranitrate (PETN), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). These materials are characterized as thin polycrystalline layers deposited in the 50 micron gap of a met...