Design of the fibers coupling grooves for MEMS optical switch on (110) silicon

2 × 2MEMS optical switch was fabricated by etching (110) silicon in aqueous KOH solution. Micromirror has smooth surface and good verticality, but it is difficult to realize self-align V-grooves. According to crystallography characteristics, two grooves with an angle of 38.94° were designed and fabricated: One is U-groove with {111} sidewalls, the other is dentate groove, which is composed of a series of etched parallelogram pits. Principle of the dentate groove was introduced, and rhombic patterns were used to compensate for undercut on convex corners of the dentate groove. Fibers can be fixed well and self-aligned in both grooves. It is an easy way to solve the problem of fabricating accurate, self-align grooves for fibers on (110) silicon.