OPTICAL-PATH DIFFERENCE MEASUREMENT FOR HIGH-RESOLUTION FOURIER SPECTROMETER

Two kinds of laser source interferometer (polarizing and absorbing bea msplitter) used for the accurate measurement of the optical path diffe rence of a Fourier transform spectrometer are described and compared. The two interferometer configurations have been used with aircraft- an d balloon-borne far-infrared spectrometers for atmospheric limb-soundi ng measurements, SAFIRE-A and IBEX. A comparison of the two implementa tions is described in this paper, and the relative performances and me rits are compared.