US Patent 7206140 Lens, lens array and optical receiver

In one embodiment, a lens has an object surface and an image surface, with the shape of the image surface being defined by an equation having a conic component and a cone component. The lens may be incorporated into an optical receiver having a photodetector that is positioned to receive light emitted from the image surface of the lens. In some uses, the image surface of the lens mitigates return loss through the lens.