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US 6,285,493 B1Granted
Electro-acoustic-optical apparatus and method of calibrating same
AssigneeTasc Ltd.
InventorsDavid T. Carrott, Mahir A. Nayfeh
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AssigneeTasc Ltd.
InventorsDavid T. Carrott, Mahir A. Nayfeh
Estimating the term…
An optically defractive medium of a Bragg cell has a moving grating induced therein in response to acoustic waves propagating in the medium. First and second electro-acoustic transducers coupled to the medium launch first and second acoustic waves toward each other in response to electric excitation of the transducers to produce a moving grating having an amplitude proportional to the difference in the amplitude of the first and second acoustic waves. A laser illuminates the medium and an optical detector array including plural individual detector elements responds to optical energy from the source, as modulated by the moving grating. A processor responds to the detector elements to derive an indication of time difference of arrival of first and second electric signals that respectively drive the first and second transducers. Anomalies of a system including the cell are detected by simultaneously driving the first and second transducers with the same electric signal and detecting the amplitude of light incident on a detector which should have a zero light amplitude incident on it under these circumstances.
An electro-acoustic-optical device comprising an optically diffractive medium capable of having a moving optical grating induced therein in response to acoustic waves propagating therein, first and second electro-acoustic transducers coupled to the optically diffractive medium for launching first and second acoustic waves toward each other in the optically diffractive medium in response to electric excitation of the first and second transducers, the transducers being positioned and arranged so that the first and second acoustic waves interact with each other in the medium.
Apparatus for combining first and second electric signals or for determining a characteristic of the apparatus in response to a third electric signal, the apparatus comprising an optically diffractive medium capable of having a moving optical grating induced therein in response to acoustic waves propagating therein, first and second electro-acoustic transducers coupled to the optically diffractive medium for launching first and second acoustic waves toward each other in the optically diffractive medium in response to electric excitation of the first and second transducers, the transducers being positioned and arranged so that the first and second acoustic waves interact with each other in the medium, an optical source for illuminating the medium, and an optical detector arrangement arranged to be responsive to optical energy from the source and modulated by the moving grating.
A method of calibrating a system including an optically refractive medium for refracting optical energy in response to acoustic waves propagating therein, as well as first and second electro-acoustic transducers coupled to the optically refractive medium for launching first and second acoustic waves toward each other in the optically refractive medium in response to electric signals supplied to the first and second transducers, the transducers being positioned and arranged so that the first and second acoustic waves interact with each other in the medium, the method comprising simultaneously supplying the same electric signal to the transducers while an optical beam is incident on the refractive medium, and detecting the amplitude of optical energy propagating through the medium while the optical beam is incident on the refractive medium.
Dependencies are inferred from the claim text.