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Proceedings Paper

Self-aligning spatial filter
Author(s): Tariq M. Haniff; Albert K. Hu; Evan D. Green
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Paper Abstract

In this paper we describe a prototype self-aligning spatial filter (SASF). We present studies of the design and the results of fabrication prior to the final processing step. The SASF consists of an electrostatically actuated platform on which an optical spatial filter (pinhole) has been fabricated. The pinhole is in the center of a four quadrant split-cell photodetector, which serves as the alignment gauge for the system. When a focused beam at the pinhole is aligned, all four detectors sense the same optical current. In future devices, this information from the photodetectors will be fed back to the electrostatic actuation system to push the platform and align the beam. The electrostatic actuators are formed from the parallel walls of vertical side- wall capacitors built between the silicon bulk and the movable platform. Electrical signal paths in the integrated system used diffused interconnects, while the photodetectors are simply reverse-biased p+n diodes. Fabrication techniques are similar to surface micromachining, except that a wafer bonding step is used to create single crystal structures.

Paper Details

Date Published: 13 July 1994
PDF: 9 pages
Proc. SPIE 2220, Sensing, Imaging, and Vision for Control and Guidance of Aerospace Vehicles, (13 July 1994); doi: 10.1117/12.179596
Show Author Affiliations
Tariq M. Haniff, California State Univ./San Jose (United States)
Albert K. Hu, California State Univ./San Jose (United States)
Evan D. Green, California State Univ./San Jose (United States)


Published in SPIE Proceedings Vol. 2220:
Sensing, Imaging, and Vision for Control and Guidance of Aerospace Vehicles
Jacques G. Verly; Sharon S. Welch, Editor(s)

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