Electromagnetic composite-based reflecting terahertz waveplate

Patent metadata

Field	Value
Publication number	US-9551820-B2
Application number	US-201213566452-A
Country	US
Kind code	B2
Filing date	Aug 3, 2012
Priority date	Aug 3, 2011
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

A reflection-mode waveplate for operation in the terahertz region by shifting the phase between two perpendicular polarization components of the light wave, comprising a ground plane; an array of polygonal unit cells; the polygonal unit cells comprising a polymer positioned between the ground plane and the exterior of the array of polygonal patches.

First claim

The invention claimed is:

1. A reflection-mode waveplate for operation in the terahertz region by shifting the phase between two perpendicular polarization components of the light wave, comprising
a ground plane;
an array of polygonal unit cells; the polygonal unit cells comprising a polymer positioned between the ground plane and the exterior of the array of polygonal unit cells configured to form a waveplate;
whereby the waveplate operates to shift the phase between two perpendicular polarization components of the light wave.

2. The waveplate of claim 1 wherein the polygonal unit cell is 119 μm×194 μm and the periodicity is 195 μm×234 μm and wherein the polymer comprises a polyimide spacer having a thickness of 68 μm and wherein the ground plane is a continuous gold ground plane, and wherein the polygonal unit cells are approximately 200 nm thick.

3. The waveplate of claim 1 wherein the waveplate is a static reflection-mode half waveplate that is arrayed in both the horizontal and vertical directions.

4. The waveplate of claim 1 wherein the waveplate is a quarter wave plate.

5. The waveplate of claim 1 wherein the waveplate is a half wave plate.

6. The waveplate of claim 1 wherein the waveplate is electrically modulated.

7. A reflection-mode waveplate for operation in the terahertz region by shifting the phase between two perpendicular polarization components of the light wave, comprising
a ground plane;
an array of polygonal unit cells; the polygonal unit cells comprising a polymer positioned between the ground plane and the exterior of the array of polygonal unit cells;
wherein the waveplate can be externally modulated either electrically or optically.

8. A waveplate comprising an array of unit cells; each unit cell comprising
a ground layer;
a polymer material layer;
a layer of GaAs;
n-type GaAs thin layer grown on the GaAs layer; and
a split ring resonator fabricated on the n-type GaAs thin layer grown on GaAs; the split ring resonator having a gap such that when a reverse bias is applied between the ground layer and the split ring resonator, the carriers in the gap are depleted and the split ring resonator resonance turns on.

9. The waveplate of claim 8 wherein the ground and polymer layers of the unit cells are contiguous.

10. The waveplate of claim 8 wherein the polymer material layer is polyimide.

11. The waveplate of claim 8 wherein the ground layer is a gold ground layer Schottky contact and the split ring resonator comprises a metamaterial ohmic contact, and wherein when a reverse bias is applied between the gold ground layer Schottky contact and the split ring resonator metamaterial ohmic contact the carriers in the gap are depleted and the split ring resonator resonance turns on.

12. The waveplate of claim 8 where the n-type GaAs thin layer is approximately 2 micrometers thick.

13. The waveplate of claim 8 wherein the split ring resonator material layer is etched such that the gap in the split ring comprises n-type GaAs.

14. The waveplate of claim 8 wherein the split ring resonator material layer is etched such that n-type GaAs only remains only in the gap of the split ring resonator material layer.

Assignees

• Metcalfe Grace D
• Wraback Michael
• Strikwerda Andrew Clare
• Averitt Richard Douglas
• Fan Kebin
• Zhang Xin
• Us Army

Inventors

• Metcalfe Grace D
• Wraback Michael
• Strikwerda Andrew Clare
• Averitt Richard Douglas
• Fan Kebin
• Zhang Xin

Classifications

• G02B5/3066

  involving the reflection of light at a particular angle of incidence, e.g. Brewster's angle · CPC title

• G02B5/3083 Primary

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title