A piezoelectrically operated optical chopper by quartz micromachining

The fabrication and operation of a piezoelectrically operated monolithic optical chopper (6 mm/spl times/7 mm) are reported. The chopper is made by anisotropic etching of a Z-cut quartz wafer (100 /spl mu/m thick) in an aqueous solution of NH/sub 4/HF/sub 2/. Newly developed piezoelectric operating scheme using meandering electrodes on a flexible quartz suspension (10/spl sim/50 /spl mu/m wide, 2 mm long) was found to produce large displacement (deforming ratio 3% by size) at a resonant frequency. Typical operational parameters are the amplitude of oscillation of 55 /spl mu/m (peak to peak) at a driving voltage of 100 V and the chopping frequency in the 2-5 kHz range depending on the suspension width and length. The resonant frequency is accurately calculated when the cross-sectional profile of the suspension is taken into account. We also successfully demonstrated a chopping operation on a collimated laser beam with the chopper.<
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