Devices, Structures, and Processes for Optical MEMS

I describe results from my research on optical MEMS at Berkeley Sensor & Actuator Center. High precision microlenses (200~1000?m diameters), fabricated utilizing hydrophobic effects and polymer-printing technology, have 343~7862?m focal lengths and show ?/5~?/80 wavefront aberrations at 635nm. Batch-processed polarization-beam splitters, made from low-stress Si3N4, produced extinction ratios of 16dB and 21dB at ?=635nm for transmitted and reflected light, respectively. Micromachined frequency-addressed microlens array can expand the dynamic range of a Shack-Hartmann (S-H) wavefront sensor beyond 144mrad, an improvement by a factor of 10 over conventional systems. High performance torsional microscanners, produced using our CMOS-compatible high-yield process, demonstrated a high-precision 2-D scan (scanning precision: 1?m on the scan plane). A fast, MEMS-based, phase-shifting interferometer with accuracy of 5.5nm, could continuously measure at rates up to 23Hz, a factor-of-23 improvement over PZT-based phase-shifting interferometers. I hope to leave you convinced, as am I, that opportunities for fruitful applications are extremely widespread in optical MEMS.

Autorentext

Hyuck Choo received the B.S. and M.Eng. degrees in Electrical Engineering from Cornell University, Ithaca, NY, and Ph.D. in Electrical Engineering and Computer Sciences from the University of California, Berkeley, CA. Presently, he is pursuing postdoctoral research at the Lawrence Berkeley National Laboratory.