Tunable optical metamaterial

Patent metadata

Field	Value
Publication number	US-9733544-B2
Application number	US-201414532774-A
Country	US
Kind code	B2
Filing date	Nov 4, 2014
Priority date	Jan 30, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A tunable metamaterial has a two dimensional array of resonant annular ring elements; and a plurality of voltage controllable electrical tuning elements disposed in or adjacent openings in each of said ring elements, each of said voltage controllable electrical tuning element ohmically contacting portions of only one of said ring elements. The voltage controllable electrical tuning elements may comprise highly doped semiconductor tunnel diodes, or the charge accumulation layer at the semiconductor/insulator interface of a metal-insulator-semiconductor structure, or nanoelectromechanical (NEMs) capacitors. The tunable metamaterial may be used, for example, in an optical beam steering device using the aforementioned tunable optical metamaterial in which a free-space optical beam is coupled into a receiving portion of a plane of the optical metamaterial and is steered out of a transmitter portion of the plane of the optical metamaterial in controllable azimuthal and elevational directions. The tunable metamaterial additionally has other applications.

First claim

The invention claimed is:

1. An optical beam steering device using tunable optical metamaterial in which a free-space optical beam is coupled into one portion of a plane of the optical metamaterial and subsequently steered out in controllable azimuthal and elevational directions from a different portion of said plane of optical metamaterial, the optical metamaterial including a two dimensional array of resonant annular ring elements, each of the resonant annular ring elements having a plurality of openings therein; and a plurality of voltage controllable electrical tuning elements disposed in or adjacent the openings in each of the resonant annular ring elements, each of the voltage controllable electrical tuning elements ohmically contacting spaced apart portions of only one of said ring elements.

2. The optical beam steering device of claim 1 wherein each of the voltage controllable electrical tuning elements comprises highly doped semiconductor tunnel diode, or the charge accumulation layer at a semiconductor/insulator interface of a metal-insulator-semiconductor structure.

3. The optical beam steering device of claim 1 wherein each of the resonant annular ring elements has a square, annular shape with four sides, each side having an opening therein for accommodating at least one of said voltage controllable electrical tuning elements.

4. The optical beam steering device of claim 3 wherein the each of the resonant annular ring elements is formed of a metallic material.

5. The optical beam steering device of claim 1 wherein each of the resonant annular ring elements has a round, annular shape of four portions, each portion being separated from an adjacent portion by an opening for accommodating at least one of said voltage controllable electrical tuning elements.

6. The optical beam steering device of claim 5 wherein the each of the resonant annular ring elements is formed of a metallic material.

7. An optical beam steering device comprising:
a two dimensional array of resonant annular ring elements, each resonant annular ring element having a plurality of openings therein; and
a plurality of voltage controllable electrical tuning elements disposed in or adjacent the openings in each of said ring elements, each of said voltage controllable electrical tuning element ohmically contacting portions of only one of said ring elements.

8. A tunable optical metamaterial comprising a two dimensional array of resonant metallic annular elements with at least four voltage controllable electrical tuning elements disposed within spaced-apart openings in annular walls of each element, each resonant metallic element in said array being resonant at optical frequencies, and voltage controllable electrical tuning elements comprising highly doped semiconductor tunnel diodes, or devices utilizing channel conductance of the charge accumulation layer at a semiconductor/insulator interface of a metal-insulator-semiconductor structure, or nanoelectromechanical capacitors.

9. A tunable optical metamaterial including an array of resonant metallic elements which are resonant to electromagnetic radiation having a wavelength longer than 0.4 microns and shorter than 0.3 mm, each of the resonant metallic elements in said array comprising a split ring having a plurality of openings in the split ring and having at least one voltage controllable electrical tuning elements disposed in each opening in the split ring and wherein each resonant metallic element has a square, annular shape with four sides, each side having an opening therein for accommodating one of said voltage controllable electrical tuning elements.

10. An optical beam steering device comprising the tunable optical metamaterial of claim 9 in which a free-space optical beam is coupled into a receiving portion of a plane of the optical metamaterial of claim 9 and is steered out of a transmitter portion of the plane of the optical metamaterial of claim 9 in controllable azimuthal and elevational directions.

11. The tunable optical metamaterial of claim 9 wherein the voltage controllable electrical tuning elements comprise highly doped semiconductor tunnel diodes, or the charge accumulation layer at a semiconductor/insulator interface of a metal-insulator-semiconductor structure.

12. A tunable optical metamaterial including an array of resonant metallic elements which are resonant to electromagnetic radiation having a wavelength longer than 0.4 microns and shorter than 0.3 mm, each of the resonant metallic elements in said array comprising a split ring having a plurality of openings in the split ring and having at least one voltage controllable electrical tuning elements disposed in each opening in the split ring and wherein each resonant metallic element has a round, annular shape with four metallic portions, each metallic portion being separated from an adjacent metallic portion by an opening for accommodating one of said voltage controllable electrical tuning elements.

13. A tunable optical metamaterial including an array of resonant metallic elements which are resonant to electromagnetic radiation, each of the resonant metallic elements in said array assuming an annular round shape having a exterior wall with a plurality of openings in said exterior wall and having one or more voltage controllable electrical tuning elements disposed within the openings in said exterior wall.

14. The tunable optical metamaterial of claim 13 wherein the exterior wall has four openings in said exterior wall for receiving said voltage controllable electrical tuning elements.

15. The tunable optical metamaterial of claim 13 wherein the voltage controllable electrical tuning elements comprise highly doped semiconductor tunnel diodes, or devices utilizing channel conductance of the charge accumulation layer at a semiconductor/insulator interface of a metal-insulator-semiconductor structure, or nanoelectromechanical capacitors.

16. The tunable optical metamaterial of claim 13 wherein the array of resonant metallic elements comprises a two dimensional array of resonant metallic elements.

Assignees

• Hrl Labroratories Llc
• Hrl Lab Llc

Inventors

• Sayyah Keyvan
• Schaffner James H
• Patterson Pamela R

Classifications

• G02F2203/15

  involving resonance effects, e.g. resonantly enhanced interaction · CPC title

• G02F2202/30

  Metamaterials · CPC title

• G02F2203/12

  spatial light modulator · CPC title

• G02F1/0018

  Electro-optical materials · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title