Digitally positioned micromirror for open-loop controlled applications

The power consumption and complexity of the close-loop control electronics are the major barriers that limit the applications of optical switches, beam steering devices and other micromirrors. To eliminate or lower the barriers, it is desirable to have a micromirror with precise, digitally positioned angles. This paper reports the first investigation to design a digitally positioned micromirror and characterize its precision levels. From the experimental results, very encouraging results have been reported for the first designed digital micromirror: +/-0.01/spl deg/ position precision has been achieved with the mirrors fabricated in the same batch but operated sporadically over a 3-month period. In order to reduce the number of the electrical drives for the mirror and increase the maximum tilting angle, an improved device was designed and tested. 0.02/spl deg//V precision has been demonstrated in the digital levels via experimental testing and +/-0.03/spl deg/ position precision of repeatability has been achieved within the angle range +/-3.5/spl deg/. The electrical-mechanical performance of the mirror is discussed here. Standard deviation of average angle and angle variance per driving voltage within the digital levels are identified to characterize the digital behavior of the mirror.