Surface micromachined devices for microwave and photonic applications

As an enabling technology, Micro Electro Mechanical Systems (MEMS) have continuously provided new and improved design/implementation paradigms for a variety of scientific and engineering applications. In this paper, we review recent advances made in MEMS and its derivative MOEM (Micro Opto Electro Mechanical) devices for both microwave and photonic applications. In the area of microwave, the MEMS switch has been regarded as one of the most crucial components. The developed switch uses a suspended silicon dioxide micro-beam as the cantilever arm, a platinum-to-gold electrical contact, and electrostatic actuation as the switching mechanism. It functions from DC to microwave frequencies and has an excellent electrical isolation (>-50 dB at 4GHz and >-25 dB at 40 GHz) and minimum insertion loss (< 0.1 dB at 4 GHz and <0.5 dB at 40 GHz). Compared to its semiconductor counterparts, the MEMS switch is superior in both performance and power consumption. In the area of photonics, the microoptical components, such as diffractive and refractive microlenses, micromirrors, beam splitter and beam combiners have received considerable attention recently. Optical systems that once were considered to be impractical due to the limitations of bulk optics can now easily be designed and fabricated with all required optical paths, signal conditioning, and electronic controls, integrated on a single chip. On-chip optical processing will enhance the performance of devices such as focal plane optical concentrators, beam shapers, Fiber Data Distribution Interface (FDDI) switch, and miniature tunable 3-D Fabry-Perot Etalon. In this paper we review advances in MEMS switches and microoptical components developed at the Rockwell Science Center. We also review the potential of on-chip optical processing and the recent achievement of free-space integrated optics and microoptical bench components developed at UCLA.