A SIMPLE SCANNING MIRROR MECHANISM FOR A FOURIER-TRANSFORM SPECTROMETER

We present a simple scanning mirror mechanism for a Fourier transform spectrometer, consisting of a voice coil actuator, a ball-bearing slid e, and a single cube corner mirror or retroreflector. The use of a sin gle cube corner reduces significantly the sensitivity of the Fourier t ransform spectrometer to the tilt of its moving mirror, enabling the s imple mechanism. With simple velocity feedback using a linear velocity transducer, we achieve a scan speed stability of 2%-5% (root-mean-squ are) for scan speeds from 40 to 440 mu m/s for a travel of 2.2 cm, cor responding to a spectral resolution of 0.06 cm(-1). Fringe amplitude s tability is about 5%. This scan mechanism was operated at standard tem perature and pressure, but the relatively minute amount of lubricant i n the ball-bearing slide may indicate possible operation under vacuum and/or cryogenic conditions. (C) 1998 American Institute of Physics.