Time-Domain THz Spectroscopy of H2O and HCl
Abstract
We demonstrate temporal evolution of rotational wavepacket of heteropolar molecules (H_2O and HCl) via THz spectroscopy. THz pulses are generated by optical rectification in ZnTe and periodically-poled LiNO3 (PPLN) using femtosecond pulses. Single-cycle THz pulses from ZnTe were passed through air with a relative humidity between 25 and 45.5 to 2.5 THz range. The broadband spectrum makes it possible to excite multiple states simultaneously. Then the system was purged with N2 to demonstrate the baseline spectrum. This is compared to known spectral data. A gas cell containing HCl gas was inserted into the system and the system N2 purged so to obtain the HCl absorption spectrum. A PPLN sample with a linearly tapered layer thickness (Pan out) is used to generate tunable narrow-band THz radiation to stimulate individual rotational states in HCl and monitor the rotational dynamics in time-domain with high spectral resolution.
- Publication:
-
APS Northwest Section Meeting Abstracts
- Pub Date:
- May 2003
- Bibcode:
- 2003APS..NWS.B2002H