Optical device and methods
AssigneeCambridge Enterprise Limited
InventorsDaping Chu, Brian Robertson
Life of this patent
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Abstract
Methods and devices for manipulating optical signals. In one example, a LCOS (liquid crystal on silicon) device includes a surface bearing an anti-reflection structure. The anti-reflection structure includes i) a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases with distance away from the surface; and ii) a configuration of the topography, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on the surface.
Claims7
An LCOS (liquid crystal on silicon) device comprising a surface bearing an anti-reflection structure, wherein:
- i) the anti-reflection structure comprises a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases in a direction that is perpendicular to said surface;
- and
- ii) a configuration of said topography comprising a stepped pyramid, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on said surface.
A method of suppressing an unwanted reflection using the LCOS device;
- wherein the LCOS device comprises a surface bearing an anti-reflection structure, and
- i) the anti-reflection structure comprises a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases in a direction that is perpendicular to said surface;
- and
- ii) a configuration of said topography comprising a stepped pyramid, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on said surface, the method comprising configuring said anti-reflection structure such that, for at least two different wavelengths, λ1, and λ2, in a first lateral spatial region of said surface, reflection from said surface at λ1 is greater than at λ2, and in a second, different lateral spatial region of said surface, reflection from said surface at λ2 is greater than λ1.
Dependencies are inferred from the claim text.