Far-infrared high-resolution Fourier transform spectrometer: applications to H(2)O, NH(3), and NO(2) lines.

A Michelson-type Fourier transform spectrometer has been constructed for high resolution work in the far ir. The instrument has a theoretical resolution of 0.007 cm(-1) and can be used with a tunable band pass filter system for the reduction of sampling points in a specific spectral region. Separations of 0.05 cm(-1) in the inversion spectrum of NH(3) in the 200-cm(-1) spectral region have been observed with about 1000 sampling points and splittings of 0.04 cm(-1) in the NO(2) spectrum at about 100 cm(-1).