High-Speed Mechanical Actuator for Precision Optical Path Length Control

Abstract

We have developed a high-speed mechanical actuator that can be used for optical systems requiring wide-band feedback control. To attain the wide-band control, we have fabricated a moving-magnet-type electromagnetic actuator with a simple structure. Using this actuator, we achieved a control system for a Michelson interferometer with a servo bandwidth defined by the unity gain frequency of the control loop as large as 30 kHz. We have also measured the amount of wobble motion of the actuator and its long-term stability. Here, we report the characteristics of the actuator.