Abstract

Where an optical component is to be automatically positioned either during fabrication or in a working instrument, an active optical-mechanical interface is required. For direct electro-mechanical displacement control to within sub-micron accuracy, piezo-electric actuators may be utilised and their range extended by 'microstepping' action.

An arrangement is described in which piezo-electric actuator elements are employed for step generation and for fine automatic feedback control between steps. Prior to each step the residual error correction in the fine control element is transferred to the stepper element thereby accommodating cumulative corrections of errors of run.

© 1980 Optical Society of America