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US 12,216,376 B2Granted
Metasurface-based active retroreflector
AssigneeThe United States of America as represented by the Secretary of the Army
InventorsSang-Yen Cho, Weimin Zhou
Life of this patent
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Abstract
An optoelectronic device apparatus using active, frequency-selective metasurfaces to achieve retroreflection at a pre-determined single frequency and optionally provide signal modulation on the reflected light beam. The apparatus may use several active, frequency-selective metasurfaces to replace traditional optical lens and mirrors.
Claims20
A retroreflector apparatus for processing an optical beam incident thereon, comprising:
- an upper metasurface separated from a lower metasurface by an optically transparent region therebetween, the optically transparent region configured to pass the incident optical beam between the upper metasurface and the lower metasurface;
- the upper metasurface having a plurality of sub-wavelength scale resonators formed thereat, the upper metasurface configured to spatially modify a local phase of an optical beam passing therethrough to shape a wavefront thereof on a lower metasurface;
- the lower metasurface disposed above a frequency-selective reflector and having a plurality of sub-wavelength scale resonators formed thereat, the lower metasurface configured to spatially modify a local phase of an optical beam passing therethrough to the reflector and to focus a reflected optical beam on the focal plane of the upper metasurface;
- the upper metasurface configured, in response to an electric voltage imparted thereto, to spatially modify a local phase or a transmitted intensity of the reflected optical beam passing therethrough to provide a frequency-selective retroreflected optical beam.
1 more element
A surveillance communications apparatus, comprising:
- a signals receiver and encoder configured to encode received signals information to provide thereby an encoded data signal;
- and
- a retroreflector, comprising:
- an upper metasurface separated from a lower metasurface by an optically transparent region therebetween, the optically transparent region configured to pass an incident optical beam between the upper metasurface and the lower metasurface;
- the upper metasurface having a plurality of sub-wavelength scale resonators formed thereat, the upper metasurface configured to spatially modify a local phase of an optical beam passing therethrough to shape a wavefront thereof on a lower metasurface;
- the lower metasurface disposed above a frequency-selective reflector and having a plurality of sub-wavelength scale resonators formed thereat, the lower metasurface configured to spatially modify a local phase of an optical beam passing therethrough to the reflector and to focus a reflected optical beam on the focal plane of the upper metasurface;
- and
- the upper metasurface configured, in response to an electric voltage imparted thereto, to spatially modify a local phase or a transmitted intensity of the reflected optical beam passing therethrough to provide a frequency-selective retroreflected optical beam;
- wherein the electric voltage is modulated in accordance with the encoded data signal.
6 more elements
Dependencies are inferred from the claim text.