Actively tunable electromagnetic metamaterial
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
In one general aspect, a tunable electromagnetic metamaterial as described herein includes a substrate and an array of split ring resonators formed on the substrate. At least one of the split ring resonators is a capacitively tuned split ring resonator. The capacitively tuned split ring resonator includes a structure having a gap and is formed of an electrically conductive material. The capacitively tuned split ring resonator also includes a region of photo-capacitive material formed in close proximity to the structure such that the capacitance of the metamaterial is changed when illuminated by controlling electromagnetic radiation having a selected range of wavelengths.
Claims25
A resonance frequency tunable 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 capacitively tuned split ring resonator, the capacitively 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 such that the capacitance of the photo-capacitive material is changed and the resonance frequency of the metamaterial is thereby tuned by below the band gap energy illumination of the photo-capacitive material;
- the metamaterial in combination with below the band gap energy electromagnetic control radiation having a selected range of wavelengths.
A method comprising:
- 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 capacitively tuned split ring resonator, the capacitively 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;
- illuminating the photo-capacitive material with below the band gap electromagnetic control radiation having a selected range of wavelengths;
- and
- by means of the photo-capacitive effect, tuning the metamaterial resonant frequency by one or more of changing a wavelength of the controlling electromagnetic radiation, changing an intensity of the electromagnetic control radiation, or changing the structure of one or more pulses of the electromagnetic control radiation.
A capacitively tuned split ring resonator comprising:
- 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 when illuminated by electromagnetic control radiation;
- the split ring resonator in combination with below the band gap energy electromagnetic radiation in the near infrared to visible range of frequencies.
A resonance frequency tunable system including:
- an electromagnetic metamaterial comprising:
- (a.) 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-capacitively 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 below the band gap energy electromagnetic radiation in the range of near infrared to visible frequencies and an electro-optical modulator controlling the below the band gap energy electromagnetic radiation therefrom;
- and
- (c.) an optical waveguide illuminating the photo-capacitive material with electromagnetic radiation from the source and electro-optical modulator.
Dependencies are inferred from the claim text.