Optical: systems and elements – Lens – Fluid
Reexamination Certificate
2008-05-05
2010-11-02
Thompson, Timothy J (Department: 2873)
Optical: systems and elements
Lens
Fluid
C359S666000
Reexamination Certificate
active
07826144
ABSTRACT:
A varifocal optical system includes a substantially circular membrane deposited on a substrate, and a ring-shaped PZT thin film deposited on the outer portion of the circular membrane. The membrane may be a MEMS-micromachined membrane, made of thermal oxide, polysilicon, ZrO2and SiO2. The membrane is initially in a buckled state, and may function as a mirror or a lens. Application of an electric voltage between an inner and outer electrode on the piezoelectric thin film induces a lateral strain on the PZT thin film, thereby altering the curvature of the membrane, and thus its focal length. Focal length tuning speeds as high as1MHz have been demonstrated. Tuning ranges of several hundred microns have been attained. The varifocal optical system can be used in many applications that require rapid focal length tuning, such as optical switching, scanning confocal microscopy, and vibration compensation in optical storage disks.
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Fenselau Matthew L.
Foley & Lardner LLP
Moore Steven A.
The Charles Stark Draper Laboratory Inc.
Thompson Timothy J
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