A CONNES TYPE INTERFEROMETER FOR FAR INFRARED SPECTROSCOPY

Author Institution: Department of Chemistry, Oakland UniversityA Connes type interferometer for use at high resolution in the far infrared has been designed and constructed in our laboratory. The basic double beam Connes design using cat’s eye retroreflectors and two detectors permits optical cancellation of the source interferogram reducing the dynamic range problem while utilizing maximum source radiation. The instrument uses a tungsten source, Bulova tuning fork chopper, and Golay detectors. Resolution is presently limited by a stepping motor lead-screw drive assembly to $0,05 cm^{-1}$ although an optimum resolution of $0.02 cm^{-1}$ should be possible after perfection of an interferometrically controlled drive. The entire optical system is enclosed in a vacuum chamber pumped to 10 microns while an internal source chamber is pumped below 0.1 micron to improve source lifetime and stability, A variable temperature multiple reflection cell is being designed to facilitate several projected spectroscopic studies