Speckle reduction
AssigneeOxford University Innovation Limited
InventorsDavid J. Hansford, Julian A. J. Fells, Steve Elston, Stephen M. Morris
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Abstract
A device (100) for speckle reduction, comprising an optical cell (110) and a controller (130). The optical cell (110) comprises a first and second cell wall (121, 122) spaced apart by a gap, and a liquid crystal composition (114) in the gap. The controller (130) is configured to cause fluid turbulence in the liquid crystal composition. The fluid turbulence in the liquid crystal composition (114) results in time varying spatially random scattering of light (102) transmitted through the liquid crystal composition (114). The liquid crystal composition (114) has a chiral nematic phase.
Claims20
A device for speckle reduction, comprising an optical cell and a controller, wherein:
- the optical cell comprises a first and second cell wall spaced apart by a gap, and a liquid crystal composition in the gap;
- wherein the liquid crystal composition has a chiral nematic phase with a pitch of 50 nm to 1000 nm;
- the controller is configured to cause fluid turbulence in the liquid crystal composition;
- the fluid turbulence in the liquid crystal composition results in time varying spatially random scattering of light transmitted through the liquid crystal composition and
- wherein the liquid crystal composition has positive dielectric anisotropy and wherein the liquid crystal composition has positive anisotropic electrical conductivity.
An optical cell, comprising:
- a first and second cell wall spaced apart by a gap, a first and second electrode for causing an electric field within the gap and a liquid crystal composition in the gap comprising mobile ions, wherein the liquid crystal composition has a chiral nematic phase with a pitch of 50 nm to 1000 nm, and wherein the liquid crystal composition is selected to exhibit fluid turbulence due to movement of the mobile ions in response to the electric field such that the fluid turbulence in the liquid crystal composition results in time varying spatially random scattering of light transmitted through the liquid crystal composition, wherein the liquid crystal composition has positive dielectric anisotropy and wherein the liquid crystal composition has positive anisotropic electrical conductivity.
A method of speckle reduction, comprising:
- transmitting a coherent light beam through a liquid crystal cell comprising a liquid crystal composition;
- wherein the liquid crystal composition has a chiral nematic phase with a pitch of 50 nm to 1000 nm;
- causing fluid turbulence in the liquid crystal composition, the fluid turbulence scattering causing dynamic scattering of the coherent light beam, wherein the liquid crystal composition has positive dielectric anisotropy and wherein the liquid crystal composition has positive anisotropic electrical conductivity.
Dependencies are inferred from the claim text.