Liquid crystal for light modulation

Patent metadata

Field	Value
Publication number	US-12468187-B2
Application number	US-202218702414-A
Country	US
Kind code	B2
Filing date	Oct 10, 2022
Priority date	Nov 2, 2021
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A liquid crystal device ( 400 ) is provided comprising: a liquid crystal layer having a thickness and comprising: a liquid crystal material; and a plurality of polymer structures ( 414 a, 414 b ) comprising polymerised liquid crystal material. Each polymer structure ( 414 a, 414 b ) is located at a different depth in the thickness of the liquid crystal layer. Electrodes are provided configured to apply an electric field to the liquid crystal layer. Each polymer structure ( 414 a, 414 b ) has a different selected locked-in liquid crystal state.

First claim

The invention claimed is:

1 . A liquid crystal device comprising:
a liquid crystal layer having a thickness and comprising: a liquid crystal material; and a plurality of polymer structures comprising polymerised liquid crystal material, each polymer structure located at a different depth in the thickness of the liquid crystal layer; and electrodes configured to apply an electric field to the liquid crystal layer; wherein each polymer structure has a selected locked-in liquid crystal state; wherein the polymer structures are arranged to provide different thicknesses of polymerised liquid crystal with a common director orientation at different lateral or radial positions in the device, the different thicknesses configured to modulate a phase of light by a different amount so as to provide a variable phase change at different areas of the device.

2 . The liquid crystal device of claim 1 , wherein at least two of the polymer structures at least partially spatially overlap one another in a direction extending through the thickness of the liquid crystal layer.

3 . The liquid crystal device of claim 1 , wherein each polymer structure is configured to provide a different spatial phase modulation of light incident on the device.

4 . The liquid crystal device of claim 1 , wherein the electrodes are configured to apply an electric field across at least a part of the liquid crystal layer.

5 . The liquid crystal of claim 4 , further comprising a first electrode and a second electrode configured to apply a field across the thickness of the liquid crystal layer.

6 . The liquid crystal device of claim 4 , wherein the electrodes are operable to apply a substantially uniform electric field.

7 . The liquid crystal device of claim 4 , wherein at least one of the electrodes comprises a plurality of individually addressable electrode elements.

8 . A liquid crystal device comprising:
a liquid crystal layer having a thickness and comprising: a liquid crystal material; and a plurality of polymer structures comprising polymerised liquid crystal material, each polymer structure located at a different depth in the thickness of the liquid crystal layer; and electrodes configured to apply an electric field to the liquid crystal layer; wherein each polymer structure has a different selected locked-in liquid crystal state, wherein each of the different liquid crystal states of the polymer structures corresponds to a state of the liquid crystal material at a different pre-determined electric field strength.

9 . The liquid crystal device of claim 8 , wherein at least one of the polymer structures comprises a plurality of regions of polymerised liquid crystal material.

10 . A liquid crystal device comprising:
a liquid crystal layer having a thickness and comprising: a liquid crystal material; and a plurality of polymer structures comprising polymerised liquid crystal material, each polymer structure located at a different depth in the thickness of the liquid crystal layer; and electrodes configured to apply an electric field to the liquid crystal layer; wherein each polymer structure has a selected locked-in liquid crystal state, wherein at least one of the polymer structures is or comprises a diffractive optical element.

11 . The liquid crystal device of claim 10 , wherein at least one of the polymer structures is or comprises a diffraction grating.

12 . The liquid crystal device of claim 11 , wherein at least one diffraction grating is configured to produce a hexatic diffraction pattern, and optionally wherein the at least one diffraction grating comprises a triangular mesh.

13 . The liquid crystal device of claim 11 , wherein at least one diffraction grating is configured to produce a 1 -D diffraction pattern, and optionally wherein the at least one diffraction grating comprises a plurality of pillars or walls.

14 . The liquid crystal device of claim 10 , wherein at least one of the polymer structures is or comprises a hologram.

15 . The liquid crystal device of claim 1 , further comprising a first substrate and a second substrate, wherein at least one of the polymer structures is tethered or secured to the first substrate or the second substrate.

16 . The liquid crystal device of claim 15 , wherein the plurality of polymer structures comprises a first polymer structure tethered or secured to the first substrate, and a second polymer structure tethered or secured to the second substrate.

17 . The liquid crystal device of claim 1 , wherein at least one of the polymer structures is at least partially tethered or secured to one or more other polymer structures.

18 . An apparatus for aberration correction, comprising the liquid crystal device of claim 1 .

19 . A holographic display device comprising the liquid crystal device of claim 13 .

20 . A method of electrically controlling spatial phase modulation of light incident on a liquid crystal device comprising:
a liquid crystal layer having a thickness and comprising: a liquid crystal material; and a plurality of polymer structures comprising polymerised liquid crystal material, each polymer structure located at a different depth in the thickness of the liquid crystal layer; and electrodes configured to apply an electric field to the liquid crystal layer; wherein each polymer structure has a selected locked-in liquid crystal state; wherein the polymer structures are arranged to provide different thicknesses of polymerised liquid crystal with a common director orientation at different lateral or radial positions in the device, the different thicknesses configured to modulate a phase of light by a different amount so as to provide a variable phase change at different areas of the device, the method comprising: applying an electric field across the liquid crystal layer to selectively control a spatial phase modulation of light incident on the device.

Assignees

• Univ Oxford Innovation Ltd

Inventors

• Sanford O'Neill John
• Salter Patrick
• Morris Stephen
• Elston Steve
• Booth Martin

Classifications

• G02F2201/305

  diffraction grating · CPC title

• G02F1/13439

  characterised by their electrical, optical, physical properties; materials therefor; method of making · CPC title

• G03H1/04

  Processes or apparatus for producing holograms (G03H1/26 takes precedence) · CPC title

• G02F1/1343

  Electrodes {(reflective electrodes G02F1/133553)} · CPC title

• G02F1/13342 Primary

  Holographic polymer dispersed liquid crystals · CPC title