Abstract

A new, compact Fourier Transform Michelson interferometer (FTUVS) with an unapodized spectral resolution of 0.07 cm^-1 has been developed for field and laboratory measurements of trace gas-phase species in the UV through visible region (200-800 nm). The instrument uses a flex pivot swing carriage mechanism driven by a voice coil actuator with a maximum translation of 5 cm. Essentially frictionless motion is achieved with high mirror velocity stability (rms velocity error less than 0.01%). Residual alighment errors are corrected dynamically to 0.1 μrad using a servo-controlled piezoelectric mirror tilt mechanism. The mirror moves at a constant velocity controlled by a commercial HP Laser Positioning System servo-axis driver which uses a 2.1 MHz Zeeman split, linearly polarized two-frequency He-Ne laser. The Doppoer shifted beam from the arm with the moving mirror is compared to the laser reference frequency for measurement and control of the mirror velocity.

© 1995 Optical Society of America