Device for modulating and reflecting electromagnetic radiation employing electro-optic layer having a variable index of refraction

• US 4,786,128 A
• Filed: 12/02/1986
• Issued: 11/22/1988
• Est. Priority Date: 12/02/1986
• Status: Expired due to Fees

• Current Assignee: Quantum Diagnostics Limited
• Original Assignee: Quantum Diagnostics Limited
• Inventors: Birnbach, Curtis A.
• Primary Examiner(s): Mullins, James B.
• Application Number:
  US06/936,761
• Time in Patent Office: 721 Days
• Field of Search: 350/96.14, 350/164, 350/356, 378/84, 378/85, 378/91
• US Class Current: 385/8
• CPC Class Codes: G02F 1/03 based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect G02F1/061 takes precedence
• CPC Class Codes: G02F 1/19 based on variable-reflection or variable-refraction elements not provided for in groups G02F1/015 - G02F1/169
• CPC Class Codes: G02F 1/21 by interference
• CPC Class Codes: G02F 2201/346 distributed (Bragg) reflector

Abstract

A multi-layer device for modulating and reflecting light. The device is formed of an electro-optic layer with a variable index of refraction sandwiched between two other layers having a pre-determined index of refraction. An electric field applied across the electro-optic layer controls the index of refraction of the layer and thus the reflectance and transmittance of light through the multi-layer stack. The device can therefore be used as a mirror, window, beam-splitter, shutter, light modulator, or other optical logic element.

Claims

1. A device for modulating and reflecting light, comprising:

(a) a layer of electro-optical material having a variable index of refraction sandwiched between two layers of dielectric material having a pre-determined index of refraction; and

(b) electrodes mounted on the outer edge portions on opposite faces of said electro-optic layer for applying a potential laterally across said electro-optic layer to vary the index of refraction of said electro-optic layer which controls the reflectance and transmittance of light through said device in a direction orthogonal to said layers.

2. A device for modulating and reflecting light as recited in claim 1, wherein said potential is applied to said electro-optic layer from two orthogonal directions.

3. A device for modulating and reflecting light as recited in claim 1, comprising a plurality of said layers of electro-optic material, each sandwiched between said layers of material having a pre-determined index of refraction.

4. A device for modulating and reflecting light as recited in claim 3, wherein the potentials applied across each of said electro-optic layers are driven independently.

5. A device for modulating and reflecting light as recited in claim 1, comprising a plurality of said layers of electro-optic material, each sandwiched between said layers of material having a pre-determined index of refraction said potential being applied to each of said electro-optic layers from two orthogonal directions.

6. A device for modulating and reflecting light as recited in claim 5, wherein the potential applied across said electro-optic layer in the first of said two orthogonal directions is driven independently of the potential applied in the second of said two orthogonal directions.

7. A device for modulating and reflecting light as recited in claim 6, wherein said potentials applied in said first and second orthogonal directions comprise a quadrature output video signal.

8. A device for modulating and reflecting light, comprising:

(a) a layer of electro-optical material having a variable index of refraction sandwiched between two layers of dielectric material having a pre-determined index of refraction; and

(b) thin layer electrodes having substantially the same pre-determined index of refraction as said two layers of dielectric material, said thin layer electrodes mounted on substantially the entirety of opposite faces of said electro-optic layer and disposed between said electro-optic layer and each of said two layers of material having a pre-determined index of refraction for applying a potential across said electro-optic layer to vary the index of refraction of said electro-optic layer which controls the reflectance and transmittance of light through said device in a direction orthogonal to said layers.

9. A device for modulating and reflecting light as recited in claim 8, wherein said potential is applied to said electro-optic layer from two orthogonal directions.

10. A device for modulating and reflecting x-rays, comprising a plurality of layers of material having a high electron density interleaved with a plurality of layers having a low electron density, wherein the transmittance of said device to x-rays travelling through said device in a direction orthogonal to said plurality of layers is increased by increasing the electron density in said layers having a low electron density by applying a current source thereto.

11. A device for modulating and reflecting x-rays, comprising a plurality of layers of material having a high electron density interleaved with a plurality of layers having a low electron density, wherein the reflectance of said device to x-rays travelling in a direction orthogonal to said pluralities of layers is increased by increasing the electron density in said layers having a high electron density by applying a current source thereto.

12. A device for modulating and reflecting x-rays, comprising a plurality of layers of material having a high electron density interleaved with a plurality of layers having a low electron density, wherein the transmittance of said device to x-rays travelling through said device in a direction orthogonal to said plurality of layers is increased by decreasing the electron density in said layers having a high electron density by applying a current sink and load thereto.

13. A device for modulating and reflecting x-rays, comprising a plurality of layers of material having a high electron density interleaved with a plurality of layers having a low electron density, wherein the reflectance of said device to x-rays travelling in a direction orthogonal to said pluralities of layers is increased by decreasing the electron density in said layers having a low electron density by applying a current sink and load thereto.