Optical system including a planar waveguide
OwnerAdrian Robert Leigh Travisinventor
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Abstract
An optical waveguide system includes a generally planar waveguide 1 arranged so that light can be injected by a projector 2 into one edge at a range of out-of-plane angles. The waveguide 1 is tapered so that different out-of-plane angles, after being totally internally reflected for a certain distance, leave the waveguide at different respective points along the waveguide. This expands the image in the direction of propagation along the waveguide. Meanwhile the image is expanded transversely by a parallel-sided input waveguide 3. A large-area flat-panel display is thus created, or the planar waveguide can be used as a planar collimating light source or, using layers of controllable optical index, an optical switch.
Claims19
An optical system including a generally planar waveguide having an input edge and a planar extent along which light can propagate by total internal reflection away from the edge, and a source of modulated light arranged to inject light rays into the input edge at a range of out-of-plane angles, the waveguide being constituted as a light-ejecting waveguide such that a ray entering at different a given out-of-plane angle is totally internally reflected up to a point where waveguiding is no longer possible and the ray thus leaves the ejecting waveguide, instead of being totally internally reflected, at different respective a point along the direction of propagation in the waveguide that corresponds to the angle of entry.
An optical modulating device including:
- a generally planar waveguide having an input edge and a planar extent along which light can propagate by total internal reflection way from the edge, the waveguide being constituted as a light-ejecting waveguide such that rays entering at different out-of-plane angles leave the waveguide, instead of being totally internally reflected, at different respective points along the waveguide,
- an input waveguide that is essentially one-dimensional and is arranged along the said input edge of the ejecting waveguide, in order to direct light input from a source substantially over the whole of the said input edge of the ejecting waveguide, and
- a source of modulated light arranged to inject light rays into the input waveguide;
- each waveguide further including an addressable part arranged to alter the position at which light leaves the respective waveguide, the source being adapted to input light into the input waveguide at a single angle and ray collection devices such as optical fibers being arranged to collect the ray emitted from the planar ejecting waveguide as the points of emission are varied.
An optical system including a generally planar waveguide having an input edge and a planar extent along which light can propagate by total internal reflection away from the edge, and a source of light arranged to inject light rays into the input edge at a range of out-of-plane angles, the waveguide being constituted as a light-ejecting waveguide such that a ray entering at a given out-of-plane angle is totally internally reflected up to a point where waveguiding is no longer possible and the ray thus leaves the ejecting waveguide, instead of being totally internally reflected, at a point along the direction of propagation in the waveguide that corresponds to the angle of entry, and further including an input waveguide arranged to direct light input from the source so that it is injected substantially over the whole of the said input edge of the ejecting waveguide, the input waveguide itself being a planner or slab waveguide with an input edge, arranged to spread light originating from a point on the input edge within the plane while preserving its out-of-plane angle, so as to inject the light into the said edge of the ejecting waveguide.
Dependencies are inferred from the claim text.