Electrically-controllable thin film Fresnel zone device
AssigneeGeneral Electric Company
InventorsAlan Purvis, Michael G. Clark
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Abstract
An optical component comprises a thin film of an electrically controllable birefringent material confined between substantially planar surfaces. A respective electrode structure is provided on each of the surfaces, each electrode structure being patterned such that an electric field applied across the film by means of electrode structures, when a voltage is applied therebetween, causes modulation of the refractive index of the material such that the wavefront of electromagnetic radiation incident of the component and transmitted through the thin film is divided into Fresnel zones.
Claims13
An electrically-controllable optical component, comprising:
- two substantially planar surfaces;
- a thin film of electrically-controllable birefringent material confined between said surfaces, said material having a refractive index;
- a respective electrode structure on each of said surfaces between which structures a voltage can be applied to apply an electric field across said thin film to cause modulation of said refractive index of said material;
- said electrode structures being patterned such that when electromagnetic radiation having a wavefront is incident on said component and said voltage is applied between said structures, then said wavefront is divided into Fresnel zones according to phase retardations impressed on said wavefront by said thin film.
Dependencies are inferred from the claim text.