Method and devices for controlling optical phase delay utilizing electrically tuned liquid crystal nano-structures

• US 20050190325A1
• Filed: 02/27/2004
• Published: 09/01/2005
• Est. Priority Date: 02/27/2004
• Status: Abandoned Application

• Current Assignee: Suning Tang
• Original Assignee: Suning Tang
• Inventors: Tang, Suning
• Application Number:
  US10/788,933
• Publication Number:
  US 20050190325A1
• Time in Patent Office: Days
• US Class Current: 349/117
• CPC Class Codes: G02F 1/13342 Holographic polymer dispersed liquid crystals
• CPC Class Codes: G02F 2201/20 delay line
• CPC Class Codes: G02F 2203/12 spatial light modulator

Abstract

A method and devices for obtaining optical phase delay utilizing electrically tuned liquid crystal nano-structures are disclosed. In one preferred embodiment, an electrically tuned liquid crystal nano-structure provides optical phase delay. The disclosed device consists of cover plates, electrodes, nanometer scaled structures with polymer regions and regions filled with liquid crystal materials, and the controlling electronic circuit. By adjusting the applied electric field in the liquid crystal nano-structure, different polarization components of the incoming light will experience different phase delays without changing their propagating direction. In another preferred embodiment, an optical polarization tuner based on aforementioned electrically tuned liquid crystal nano-structures is disclosed. The polarization tuner consists of an polarization beam splitter, two electrically tuned liquid crystal nano-structures, and two beam folding prisms. By adjusting the applied electrical fields through the two liquid crystal nano-structures, light outputs with different polarization states are obtained. In yet another preferred embodiment, a spatial light modulator device based on aforementioned electrically tuned liquid crystal nano-structures is disclosed. The spatial light modulator consists of a nano-structured liquid crystal, a multi-channel electrode structure and controlling electronic circuit. The multi-channel electrode structure can be used to establish different electrical fields in different spatial regions such that the phase of the incoming light can be modified with spatial specificity.

Claims

1. An optical phase delay device for providing phase delayed optical outputs comprising:

at least two parallel covering plates having a physical separation in between;

regions of polymer materials spaced by a distance substantially smaller than one micrometer;

regions of liquid crystal particles interleaving the said regions of polymers;

and a group of electrodes being fabricated near the said covering glass plates.

2. The optical phase delay device recited in claim 1 wherein the said covering plates being glass plates.

3. The optical phase delay device recited in claim 1 wherein the said liquid crystal regions having an ordinary refractive index n_o and an extraordinary refractive index n_e.

4. The optical phase delay device recited in claim 1 wherein the said polymer regions having an index of refraction n_p.

5. The optical phase delay device recited in claim 1 wherein the said polymer regions and liquid crystal regions being fabricated through a photolithography method.

6. The optical phase delay device recited in claim 1 wherein the said liquid crystal regions containing liquid crystal materials.

7. The optical phase delay device recited in claim 1 wherein the said polymer regions and liquid crystal regions being fabricated through a photolithography method using patterned phase masks and/or using patterned holographic two beam interference methods.

8. The optical phase delay device recited in claim 1 wherein the said electrodes being fabricated with electrically conductive materials such as metals, ITO (Indium-Tin oxide), and/or conductive polymeric mixtures.

9. The optical phase delay device recited in claim 1 wherein the said electrodes being fabricated through a photolithography method.

10. The optical phase delay device recited in claim 1 wherein the said cover plate being optically coupled to at least one polarization beam splitters.

11. The optical phase delay device recited in claim 1 wherein the said cover plate being optically coupled to at least one prism.

12. The optical phase delay device recited in claim 1 wherein the said polymer regions having separations measuring from 1 to 1000 nanometers.

13. The optical phase delay device recited in claim 1 wherein the said cover plates having a separation distance of 1 micrometers to 500 micrometers.

14. A method for providing optical phase delay comprising the following steps:

using a collimated light source having specific wavelength;

passing the input light to an electrically tuned liquid crystal nano-structure consisting of alternating polymer and liquid crystal regions;

applying electrical voltages to electrodes near the said liquid crystal nano-structure to tune the said optical phase delay.

15. The method recited in claim 14 wherein the said liquid crystal regions having an ordinary refractive index n_o and an extraordinary refractive index n_e.

16. The method recited in claim 14 wherein the said polymer regions having an index of refraction n_p.

17. The method recited in claim 14 wherein the said polymer regions and liquid crystal regions being fabricated through a photolithography method.

18. The method recited in claim 14 wherein the said liquid crystal regions containing liquid crystal materials.

19. The method recited in claim 14 wherein the said polymer regions and liquid crystal regions being fabricated through a photolithography method using patterned phase masks and/or using holographic two beam interference methods.

20. The method recited in claim 14 wherein the said the said electrodes being fabricated with electrically conductive materials such as metals, ITO (Indium-Tin oxide), and/or conductive polymeric mixtures.

21. The method recited in claim 14 wherein the said liquid crystal regions being optically coupled to at least one polarization beam splitters.

22. The method recited in claim 14 wherein the said polymer regions having separations measuring from 1 to 1000 nanometers.

23. The method recited in claim 14 wherein the said cover plates having a separation distance of 1 micrometers to 500 micrometers.