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arXiv · 1507.05322

New terahertz dielectric spectroscopy for the study aqueous solutions

Deepu K. George·Ali Charkhesht·N. Q. Vinh
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Abstract

We present a development of a high precision, tunable far-infrared (terahertz) frequency-domain dielectric spectrometer for studying the dynamics of biomolecules in aqueous solutions in the gigahertz-to-terahertz frequency. As a first application we report on the measurement of the absorption and refractive index for liquid water in the frequency range from 5 GHz to 1.12 THz (0.17 to 37.36 cm-1 or 0.268 to 60 mm). The system provides a coherent radiation source with a power up to 20 mW in the gigahertz-to-terahertz region. The power signal-to-noise ratio of our instrument reaches 1015 and the system achieves a spectral resolution of less than 100 Hz. The temperature of samples can be controlled precisely with an error bars of 0.02 oC from above 0 oC to 90 oC. Given these attributes, our spectrometer provides unique capabilities for the accurate measurement of even very strongly absorbing materials such as aqueous solutions.

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Deepu K. George, Ali Charkhesht, N. Q. Vinh. 2015-07-19. New terahertz dielectric spectroscopy for the study aqueous solutions. https://doi.org/10.1063/1.4936986

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