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US 4,567,451 AGranted
Resonator having optical feedback coupling
AssigneeInternational Standard Electric Corporation
InventorJohn C. Greenwood
Life of this patent
Estimating the term…
Abstract
A resonator device comprises an elastic beam driven electrostatically at its natural frequency, or an harmonic thereof, by voltage pulses applied to an integral paddle member. The voltage pulses are derived from optical pulses fed via an optical fibre and reflected from the paddle member to a photodiode array. There is thus minimal coupling between the beam and the drive system. A positive feedback loop is provided in which light retroreflected from the paddle member is recaptured by the optical fibre and electronically detected, amplified and fed back in phase with the beam oscillations by modulating the optical pulses.
Claims9
In a resonator device of the type having:
- a substrate;
- a pair of end mount means both secured to said substrate;
- filament means mounted between said end mount means for torsional vibration;
- paddle means integral with said filament means and located intermediate said end mount means to participate in said torsional vibration;
- and oscillation driving means for driving said paddle means to perform said torsional vibration, and including means for sensing said torsional vibration, and in response thereto providing positive feedback to sustain said torsional vibration;
- the improvement wherein:
- said filament means is integral with said mount means;
- and
- said filament means comprises a plurality of individual filaments, each of which is integral with said end mount means and said paddle means.
6 more elements
In a resonator device of the type having:
- a substrate;
- a pair of end mount means both secured to said substrate;
- filament means mounted between said end mount means for torsional vibration;
- paddle means integral with said filament means and located intermediate said end mount means to participate in said torsional vibration;
- and oscillation driving means for driving said paddle means to perform said torsional vibration, and including means for sensing said torsional vibration, and in response thereto providing positive feedback to sustain said torsional vibration;
- the improvement wherein:
- said filament means is integral with said end mount means;
- said oscillation driving means includes a light source, photovoltaic means positioned to receive light from said light source, and electrode means positioned for electrostatically deflecting said paddle means, the electrical output of said photovoltaic means produced in response to said received light being connected to energize said electrode means to drive said paddle means;
- and said feedback means includes means for illuminating said paddle means, photoconductive means for receiving light reflected from said paddle means, and means for positively feeding back the output of said photoconductive means to modulate said light source;
- said oscillation driving means and said feedback means comprise a common light pipe means to conduct light from said light source to illuminate both said photovoltaic means and said paddle means;
- and,
- said light pipe means being arranged to (a) illuminate said paddle means in such manner that light is reflected from said paddle means to said photovoltaic means, and to (b) receive light retroreflected from said paddle means and conduct it to said photoconductive means.
9 more elements
In a resonator of the type having:
- substrate means;
- an oscillating element;
- means supporting said oscillating element on said substrate means for oscillatory motion;
- oscillation driving means including a light source, photovoltaic means positioned to receive light from said light source, and electrode means positioned for electrostatically deflecting said oscillating element, the electrical output of said photovoltaic means produced in response to said received light being connected to energize said electrode means to drive said oscillating element;
- and feedback means including means for illuminating said oscillating element, photoconductive means for receiving light reflected from said oscillating element, and means for positively feeding back the output of said photoconductive means to modulate said light source;
- the improvement wherein:
- said oscillation driving means and said feedback means comprise a common light pipe means to conduct light from said light source to illuminate both said photovoltaic means and said oscillating element;
- said light pipe means being arranged to (a) illuminate said oscillating element in such manner that light is reflected from said oscillating element to said photovoltaic means, and to (b) receive light retroreflected from said oscillating element and conduct it to said photoconductive means.
5 more elements
Dependencies are inferred from the claim text.