Focal surface

Abstract: An optical filter device comprised of two parallel arrays of lenses. Each lens in the first array faces a lens in the second array to form a pixel. Lens pairs in a pixel are separated by the sum of their focal distances and include in their common focal surface a "smart" layer for modulating light passing through the focal surface. Preferred embodiments include car rear view mirrors, sunglasses, glasses for night driving, laser goggles, nuclear goggles, sun visors, sun shields, windshields, space suit helmet visors, optical instrument protection devices, window filters and energy conservation devices.

Abstract: An image sensor module includes a flexible support mounted with a flexible substrate that includes optical circuitry on its surface. The substrate is formed sufficiently thin so that it can be shaped into a curved configuration. The combination of substrate and support can be mounted inside an optically transmissive housing and shaped into a variety of curved configurations that match the curved focal surface of a lens. In another approach, the support is a rigid support having a curved surface contour that substantially corresponds to a curved focal surface of a lens. The substrate is coupled with the curved surface contour of the rigid support and mounted with a lens such that the optical circuitry of the substrate obtains a curve that substantially matches that of the focal surface of the lens. Methodologies for fabricating the above modules are also disclosed.

Abstract: A new lens antenna for wide-angle beam-steering application is presented. The 2-D lens permittivity profile according to Luneburg is modified using transformation optics to obtain a planar focal surface, allowing for a simple cost-effective planar feed technology. A slice of the lens is confined between two metallic surfaces forming a parallel-plate transmission line, enabling beam-steering in the plane containing the slice. Stacking up such slices result in a more focused beam and beam-steering capabilities in the perpendicular plane. As a result, full 2-D beam-steering becomes possible, with a very wide steering range of ±60° in one plane and a smaller steering range of ±15° in the orthogonal plane. The inhomogeneous dielectric slice is made of four dielectric materials with different permittivity, with a pattern of drilled holes of different diameters realizing a smooth gradient of the effective permittivity. The measured performance of the antenna prototype, operating at about 10 GHz includes 17.2 dB maximum directivity, a scan loss better than 0.8 dB, a sidelobe level better than 11 dB, and an aperture efficiency of 74%, outperforming any other reported beam steering antenna with planar focal surface.

Abstract: Luneburg lens with flat focal surface has been developed to work together with planar antenna feeds for beam steering applications. According to our analysis of the conventional flattened Luneburg lens, it cannot accommodate enough feeding elements which can cover its whole scan range with half power beamwidths (HPBWs). In this paper, a novel Luneburg lens with extended flat focal surface is proposed based on the theory of Quasi-Conformal Transformation Optics (QCTO), with its beam steering features reserved. To demonstrate this design, a three-dimensional (3D) prototype of this novel extend-flattened Luneburg lens working at Ku band is fabricated based on 3D printing techniques, whose flat focal surface is attached to a 9-element microstrip antenna array to achieve different scan angles. Our measured results show that, with different antenna elements being fed, the HPBWs can cover the whole scan range.