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US 2023/0175893 A1Published application
Conformal imaging vibrometer using adaptive optics with scene-based wave-front sensing
AssigneeDavid Mort Pepper
InventorDavid Mort Pepper
Life of this patent
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Abstract
Conformal imaging vibrometer using adaptive optics with scene-based wave front sensing. An extended object is located at the first end of a link, and a reference-free, adaptive optical, conformal imaging vibrometer using scene-based wave front sensing is located at the second end of the link. An aberrated, free space or guided-wave path exists between the ends of the link. The adaptive optical system compensates for path distortions. Using a single interrogation beam, whole-body vibrations of opaque and reflective objects can be probed, as well as transparent and translucent objects, the latter pair employing a Zernike heterodyne interferometer.
Claims23
A system for adaptive optical reference-free conformal imaging vibrometry, comprising:
- a plurality of optical elements arranged according to an arbitrary geometry of a structure or object, configured to emit a single source beam to conform to the arbitrary geometry of the structure and substantially orthogonally illuminate a surface at multiple locations to form a plurality of signals resulting from the scattered or transmitted light, each optical signal including information for measuring a surface displacement or a velocity or an acceleration at multiple measurement locations on the structure;
- an optical receiver to collect said scattered or transmitted light from said object through a distorted path;
- a scene-based wave front sensor arranged in a closed-loop configuration to drive an adaptive optical tip-tilt compensator and a deformable optical element to compensate for path distortions;
- a 2-d optical video receiver to detect a compensated image of the object under evaluation;
- a multi-channel optical interferometer to coherently detect surface vibrations of said object under evaluation;
- a multi-channel receiver configured to receive the plurality of optical signals from said multi-channel interferometer and to generate a plurality of analog signals;
- a multi-channel converter for adapting the plurality of said analog signals into a plurality of digital signals;
- a multi-channel processor configured to process the plurality of said digital signals to determine the surface displacement or the surface velocity or the surface acceleration of at multiple locations on said object and to reconstruct said compensated images to display the real-time structural dynamics in real-time based on the surface displacements or the surface velocities or the surface accelerations;
- a diffraction-limited laser emitter directed in a substantially reverse-propagating direction with respect to said received scattered or transmitted light by said object;
- a first spatial light modulator to encode inverted wave front information onto said laser emitter beam;
- a second spatial light modulator to encode compensated image information onto said laser emitter beam;
- and
- an optical transmitter to direct said emitter beam in a substantially reverse direction with respect to said received scattered light.
10 more elements
A method for adaptive optical conformal imaging vibrometry, comprising:
- substantially orthogonally illuminating an object;
- receiving said illuminated light from said object;
- establishing a two-way communications link between said object and an optical transceiver through path distortions;
- generating an inverted wave front of said received light using a scene-based wave front sensor in a closed-loop adaptive optics configuration;
- compensating for said path distortions encountered by said object using said inverted wave front;
- generating a compensated image of said object;
- detecting 2-d video information of said compensated image using direct detection;
- generating said direct detected video signal of said compensated image;
- generating a laser beam possessing a diffraction-limited planar wave front;
- generating a local oscillator beam using said laser beam;
- detecting said 2-d video information of said compensated image using coherent detection with said local oscillator;
- generating a 2-d coherently detected video signal of said compensated image;
- executing a multi-point measurement of dynamic motions of said object to reveal said object’s displacement, velocity or acceleration as a function of location and time across said object, using said 2-d coherently detected video signal;
- analyzing said multi-point measurement using a multi-channel channelizer with image processing algorithms as known in the art;
- comparing said direct detected video signal against said coherent detected signal using said multi-channel analyzer with conventional image processing and algorithm techniques to obtain a vibrational signal across the surface of said object as a function of location and time;
- encoding said wave front inverted phase front information onto said laser beam by a first spatial light modulator and tip-tilt compensator;
- further encoding said compensated image information onto said laser beam by a second spatial light modulator;
- transmitting said encoded laser beam in a substantially reverse direction relative to said received light;
- propagating said encoded laser beam through said distortion in a substantially reverse direction relative to said received light;
- transmitting said encoded beam back to said object location, thereby completing the communications link and illuminating the whole-body of said object with a single beam;
- illuminating said object with said compensated image;
- and repeating and iterating said vibrometer process with illuminated object.
19 more elements
Dependencies are inferred from the claim text.