Dynamically variable metamaterial lens and method
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsDonald W. Rule, Kevin A. Boulais, Francisco Santiago
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Abstract
A dynamically variable lens is made from actively tunable electromagnetic metamaterial cells. The lens operates on electromagnetic radiation including: radio frequency waves, microwaves, teraherz waves, near infrared waves, infrared waves and visible waves. The focal length of the lens is changed at a selected frequency. In the alternative, the frequency of radiation operated on is changed as a function of time. A third alternative provides precise control of the index of refraction of the lens. The index of refraction is varied progressively across the lens from one edge to the opposite edge causing the radiation to be directed at an angle.
Claims27
A dynamically variable lens comprising an array of resonance frequency tunable metamaterial cells arranged in two or three dimensions, each metamaterial cell including:
- a substrate and a capacitance tuned split ring resonator formed on the substrate, wherein:
- the capacitance tuned split ring resonator includes a structure having a gap and formed of an electrically conductive material and a region of photo-capacitive material formed in close proximity to the structure such that the capacitance of the photo-capacitive material is changed and the resonance frequency of the metamaterial cell is thereby tuned by control illumination of the photo-capacitive material with at the band gap and below the band gap energy.
A method of dynamically varying a lens comprising:
- (a.) providing a resonance frequency tunable electromagnetic metamaterial, the metamaterial comprising
- a substrate;
- and
- an array of split ring resonators formed on the substrate, wherein:
- at least one of the split ring resonators comprises a capacitance tuned split ring resonator, the capacitance tuned split ring resonator including a structure having a gap and formed of an electrically conductive material and a region of photo-capacitive material formed in close proximity to the structure;
- (b.) illuminating the photo-capacitive material with at the band gap and below the band gap electromagnetic control radiation having a selected range of wavelengths;
- and
- (c.) by means of the photo-capacitive effect, tuning the metamaterial with the control electromagnetic radiation.
A resonance frequency tunable system including:
- (a.) a dynamically tunable lens comprising an electromagnetic metamaterial comprising:
- a substrate and an array of split ring resonators formed on the substrate, wherein:
- at least one of the split ring resonators comprises a photo-capacitance tuned split ring resonator including an electrically conductive structure and a region of photo-capacitive material formed in close proximity to the structure;
- (b.) a source of at the band gap and below the band gap energy electromagnetic radiation in the range of radio frequency waves to visible frequencies and an electro-optical modulator controlling the at the band gap and below the band gap energy electromagnetic radiation therefrom;
- and
- (c.) an optical wave guide illuminating the photo-capacitive material with electromagnetic radiation from the source and electro-optical modulator.
Dependencies are inferred from the claim text.