Patent ID: 7643148

Claim:
A method of Fourier Transform THz Spectroscopy comprising the steps of: a) providing a resonance cavity having first parabolic mirror facing a second parabolic mirror at opposing ends thereof, with a THz. signal mixer and a THz source in signal communication with the resonance cavity and the mixer, b) placing a sample to be analyzed in the resonance cavity, c) generating a THz signal by the THz source, whereby the generated THz signal is input to the resonance cavity and the mixer, d) combining the output signal from the chamber with the input signal at the mixer to form a mixed signal at a first resonant frequency of the cavity, e) varying the distance between the first mirror and the second mirror to changes the resonant frequency of the cavity, f) acquiring the mixed signal at a plurality of resonant frequencies defined by the distance between the first and second mirrors to obtain a spectral response from the sample, g) analyzing the acquired spectral response to determine the presence of particular molecular species in the sample.