Driving Voltage Reduction of a Micromechanical Optical Switch Driven by Electrostatic Force Using an S-Shaped Deformable Thin-Film Mirror

Abstract

This paper describes the driving voltage reduction of an optical switch that has an S-shaped deformable thin-film mirror driven by an electrostatic force. The prototype optical switch has high-dielectric-constant layers made from Ta2O5 for a low applied voltage to generate a sufficiently large attractive force. Although the dielectric layers are effective at increasing the attractive force, they often cause a charging problem. Thus, suitable driving procedures for solving the charging problem were experimentally examined. In the two driving procedures, AC or DC voltage inputs were used. The experimental results indicate that the driving procedures are effective at reducing the driving voltage to 30 V. However, the results also show that the AC components induce a residual vibration of the spot position. Consequently, the driving procedure with the DC voltage input is proven to be more suitable.

Keywords

• optical switch
• electrostatic force
• s shape
• thin-film mirror
• dielectric layer
• charging
• driving voltage