Norinao Koma

A rotational comb-driven micromirror with a large deflection angle and low drive voltage

We have designed, fabricated, and tested a V-shaped torsion bar for use with a comb-driven micromirror. This torsion bar suppressed undesired sticking of the comb teeth, and enabled a large rotational angle and a low drive voltage. We observed 5-degree rotation of a comb-driven micromirror with a drive voltage of 90 V.

A scanning mirror with extremely high resonance frequency up to 0.51 MHz using both torsion and buckling springs

This paper reports about a single-crystalline Si mirror of around a millimeter in size used for laser beam scanning in an optical measurement system in a vacuum. The miniature mirror is capable of scanning at an extremely high-speed of up to 0.5 MHz, and uses a new rotation vibration mechanism involving both torsion and buckling springs. The mirror is fabricated using deep reactive-ion-etch (DRIE) and anodic bonding technologies. The efficacy of the new mechanism is demonstrated by measuring two fabricated scanning mirrors, one having a 0.15 MHz resonance frequency and the other a 0.51 MHz resonance frequency. This paper will explain the concept, fabrication process and discuss the experimental results.