Capacitive feedback controlled PZT micro mirror arrays for wavelength selective switch

We developed a single-axis mechanical micro mirror array used for gridless wavelength selective switch (WSS). The mirrors are driven by lead zirconate titanate (PZT) unimorph actuators, which is adequate for low-voltage actuation and low interference with adjacent mirrors in operation. In addition, the mirror tilt angle is feedback-controlled using comb-shaped capacitance in order to realize high control resolution. We fabricated a prototype mirror array by using simple semiconductor wafer process technologies, and evaluated its basic performance. In conclusion, we realized a high fill factor of over 98%, 5 mechanical angle at 10 V, and high control resolution under 0.01.