Michelson interferometer with a rotating retroreflector: a laboratory model for environmental monitoring

Designed for atmospheric pollution monitoring, a breadboard model of a new Michelson interferometer has been developed. It utilizes a nutating retroreflector to generate alterations in the geometrical and optical paths. The forward-backward stop-and-go movement of a reflecting element of conventional Michelson interferometers is thus replaced by a continuous rotation. At this state the instrument employs a 6.3-cm (2.5-in.) diam rotating retroreflector, a ZnSe beam splitter, and a HgCdTe detector at liquid nitrogen temperature, sensitive in the 8-14-microm band. It allows spectral resolutions of up to 2 cm(-1). The device is linked via an analog digital interface to a desktop computer which performs interferometer control, data acquisition, Fourier transform, and display of the spectra.