LIQUID CRYSTAL WAVEGUIDE HAVING REFRACTIVE SHAPES FOR DYNAMICALLY CONTROLLING LIGHT

• US 20080008414A1
• Filed: 07/06/2007
• Published: 01/10/2008
• Est. Priority Date: 01/22/2004
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Vescent Photonics Incorporated
• Inventors: Anderson, Michael, Davis, Scott, Rommel, Scott
• Granted Patent: US 8,380,025 B2
• Time in Patent Office: Days
• US Class Current: 385/008
• CPC Class Codes: G02F 1/133757 with different alignment orientations
• CPC Class Codes: G02F 1/295 Analog deflection from or in an optical waveguide structure]

Abstract

Liquid crystal waveguides for dynamically controlling the refraction of light. Generally, liquid crystal materials may be disposed within a waveguide in a cladding proximate or adjacent to a core layer of the waveguide. In one example, portions of the liquid crystal material can be induced to form refractive or lens shapes in the cladding that interact with a portion (e.g. evanescent) of light in the waveguide so as to permit electronic control of the refraction/bending, focusing, or defocusing of light as it travels through the waveguide. In one example, a waveguide may be formed using one or more patterned or shaped electrodes that induce formation of such refractive or lens shapes of liquid crystal material, or alternatively, an alignment layer may have one or more regions that define such refractive or lens shapes to induce formation of refractive or lens shapes of the liquid crystal material. In another example, such refractive or lens shapes of liquid crystal material may be formed by patterning or shaping a cladding to define a region or cavity to contain liquid crystal material in which the liquid crystal materials may interact with the evanescent light.

Claims

1. A method for dynamically controlling refraction of light through a waveguide having a core and at least one cladding, comprising:

providing a liquid crystal material within said at least one cladding;

providing for forming at least one refractive shape from said liquid crystal material in said at least one cladding; and

providing for passing an evanescent portion of said light through said at least one refractive shape, thereby refracting the light.

2. The method of claim 1, wherein the at least one cladding includes an upper and lower cladding, and wherein the operation of providing a liquid crystal material further comprises:

providing the liquid crystal material in said upper cladding.

3. The method of claim 1, wherein the at least one cladding includes an upper and lower cladding, and wherein the operation of providing a liquid crystal material further comprises:

providing the liquid crystal material in said lower cladding.

4. The method of claim 1, wherein the operation of providing for forming at least one refractive shape further comprises:

providing for applying an electric field to at least a portion of the liquid crystal material, thereby inducing said portion of the liquid crystal material to form at least one refractive shape.

5. The method of claim 4, wherein the at least one refractive shape has a variable index of refraction, the method further comprising:

providing for varying the electric field, thereby adjusting the variable index of refraction of the at least one refractive shape.

6. The method of claim 1, wherein the operation of providing for forming at least one refractive shape further comprises:

providing at least one electrode for receiving at least one voltage;

forming said electrode to include at least one refractive shape; and

providing for applying a voltage to said electrode thereby inducing said portion of the liquid crystal material to form at least one refractive shape.

7. The method of claim 6, further comprising:

providing for varying the voltage applied to said electrode in order to adjust an index of refraction of the at least one refractive shape.

8. The method of claim 1, wherein the operation of providing for forming at least one refractive shape further comprises:

providing at least one alignment layer adjacent at least one cladding;

forming the alignment layer to have at least a first region biasing said liquid crystal material in a first orientation, and the alignment layer having a second region biasing said liquid crystal material in a second orientation, said second region defining at least one refractive shape;

providing at least one electrode for receiving at least one voltage, said electrode defining a plane; and

providing for applying a voltage to said electrode, thereby re-orienting the liquid crystal material in the at least one cladding.

9. The method of claim 8, wherein the first region has a first index of refraction and the second region has a second index of refraction, the method further comprising:

providing for varying the voltage applied to said at least one electrode in order to adjust a difference between the first and second index of refraction.

10. The method of claim 1, wherein the operation of providing for forming at least one refractive shape further comprises:

forming a cavity in the at least one cladding, the cavity defining at least one refractive shape;

placing the liquid crystal material in said cavity;

providing for applying an electric field to said cavity, thereby re-orienting the liquid crystal material in the cavity.

11. The method of claim 10, wherein the liquid crystal material in the cavity has an index of refraction, and when the electric field is applied to the cavity, the index of refraction of the liquid crystal material in the cavity changes, thereby altering an amount of refraction of the light in the waveguide.

12. The method of claim 10, wherein the operation of providing for applying an electric field further comprises:

providing at least one electrode for receiving at least one voltage, said electrode defining a plane; and

providing for applying a voltage to said electrode.

13. A method for dynamically controlling refraction of light through a waveguide having a core and at least one cladding, comprising:

providing a liquid crystal material disposed within said at least one cladding;

providing at least one electrode; and

providing for applying a voltage to said electrode to refract the light in the waveguide.

14. The method of claim 13, wherein the operation of providing for forming at least one refractive shape further comprises:

providing at least one alignment layer adjacent at least one cladding;

forming the alignment layer to have at least a first region biasing said liquid crystal material in a first orientation, and the alignment layer having a second region biasing said liquid crystal material in a second orientation, said second region defining at least one refractive shape;

providing at least one electrode for receiving at least one voltage, said electrode defining a plane; and

providing for applying a voltage to said electrode, thereby re-orienting the liquid crystal material in the at least one cladding.

15. The method of claim 14, wherein the first region has a first index of refraction and the second region has a second index of refraction, the method further comprising:

providing for varying the voltage applied to said electrode in order to adjust a difference between the first and second index of refraction.

16. The method of claim 13, wherein the operation of providing for forming at least one refractive shape further comprises:

forming a cavity in the at least one cladding, the cavity defining at least one refractive shape;

placing the liquid crystal material in said cavity;

providing for applying an electric field to said cavity, thereby re-orienting the liquid crystal material in the cavity.

17. The method of claim 16, wherein the liquid crystal material in the cavity has an index of refraction, and when the electric field is applied to the cavity, the index of refraction of the liquid crystal material in the cavity changes, thereby altering an amount of refraction of the light in the waveguide.

18. A method for controlling refraction of a light beam through a waveguide having a core and at least one cladding, comprising:

providing a liquid crystal material within said at least one cladding;

providing for forming at least one refractive shape from said liquid crystal material in said at least one cladding; and

providing at least one alignment layer adjacent the core, said alignment layer inducing a substantially uniform arrangement of the liquid crystal material of the at least one refractive shape; and

providing for passing the light beam through the waveguide, wherein an evanescent portion of the light beam interacts with the at least one refractive shape having the substantially uniform arrangement of the liquid crystal material, thereby reducing attenuation of the light beam as it travels through the waveguide.

19. The method of claim 18, wherein the operation of providing for forming at least one refractive shape further comprises:

providing at least one electrode for receiving at least one voltage;

forming said electrode to include at least one refractive shape; and

providing for applying a voltage to said electrode thereby inducing said portion of the liquid crystal material to form at least one refractive shape.

20. The method of claim 19, further comprising:

providing for varying the voltage applied to said electrode in order to adjust an index of refraction of the at least one refractive shape.