Abstract

We describe the design and preliminary performance of a Fourier transform spectrometer (FTS) built to operate in both the visible and UV regions. Conventional FTS instruments have generally been restricted to use in the IR because of the difficulties in providing sufficiently precise control of the mirror velocity and alignment. We are building an FTS, which uses a laser-diode source, in which both mirror motion and alignment are dynamically controlled on the basis of interferometric signals. By using a multi-phase detection technique, we are able to make interferometric measurements with /768 precision at a 5 MHz update rate. These data are used to servocontrol the mirror velocity and alignment to better than 0.01% and 1 radian respectively. This degree of control, combined with optics that are good to /40 in the visible-light spectrum, make it possible to attain spectral resolution in the visible and near-UV regions that is limited only by radiometric noise considerations.

© 1990 Optical Society of America