Determination of a micromirror angular rotation using laser interferometric method

Abstract

This paper presents an optical method for the measurement of the angular rotation of a micromirror driven by an electrostatic force. To detect the rotation of the micromirror, a He-Ne laser probe with a collimated light beam of 30 μm in diameter is directed onto the micromirror with an achromatic lens. The laser beam reflected off the micromirror falls on the achromatic lens and is combined with another laser beam from a reference mirror. The resulting interference fringe pattern is recorded and the angular rotation of the micromirror is determined from the change in the pitch of the fringe pattern. Experimental results obtained demonstrate the feasibility of the proposed method to be used for evaluating the angular rotation of a micromirror. © 2001 Elsevier Science B.V. All rights reserved.