Detection of van der Waals Vibrational Transitions
Using a New MW-THz Double Resonance Technique.
Vladimir Markov, Yunjie Xu and Wolfgang Jäger
Department of Chemistry, University of Alberta, Edmonton AB T6G 2G2, Canada
A new double resonance technique has been developed that can be used for the detection of low frequency van der Waals vibrations. The technique uses backward wave oscillators (OB-24, OB-30, ISTOK), which are phase-locked to a KVARZ mm-wave synthesizer (78–118 GHz), as pump sources, and a pulsed jet cavity Fourier transform microwave spectrometer for detection. Initial measurements were done on the Ar-CO system for which the THz frequencies of ro-vibrational transitions from the ground to the first excited van der Waals bending state were known from previous measurements. Resolving power and sensitivity of the technique will be discussed.