Real Pivot Mechanism of Rotary Comb-Drive Actuators for MEMS Continuously Tunable Lasers

This paper presented the theoretical and experimental studies on a new mechanism of real pivot by use of a double-clamped beam. Comparison with the conventional virtual pivot formed by a cantilever beam, such real pivot provides large rotation angle and small position shift, which is key for the MEMS tunable lasers to obtain continuous wavelength tuning over a wide range. In experiment, the real pivot is able to produce a rotation angle of 4.7 degrees regardless of a depth variation of 16 % over the double-clamped beam due to fabrication error. In contrast, the virtual pivot has only 2.4 degrees in the presence of 4 % depth reduction. The real pivot design is more suitable for the MEMS tunable lasers as it is simple, symmetric, robust and allowable for single-chip integration.