A free space 100 GHz bridge spectrometer for the study of atmospheric gases

Abstract

A gas microwave bridge spectrometer for the study of the shape of overlapping lines at pressures up to 1 atm is described. A novel free space cell is used, which has low transmission losses (below 5 dB for the 8 m cell) and minimizes reflections from the cell walls. This enables absolute determination of the absorption and refraction of gases when high sensitivity and resolution is required. Preliminary measurements are reported.