MIRROR SCAN VELOCITY CONTROL

摘要

Mirror scan control for driving a movable mirror of an interferometer in an infrared spectrophotometer, with constant scan velocity and accurate position determination, using a laser (18) emitting a two frequency beam, a standard Michelson interferometer (13) a reference signal synthetizer (54). A closed loop electronic servo control controls velocity through comparison of the signal (80) from detector (44) with a controlled frequency reference signal. A second loop is used for stabilizing the frequency difference of laser frequency components. Phase lock control techniques are used for locking the signal detected to a common reference signal also used by the laser servo control.