Systems and methods for optical imaging using an optical sensor in an active area of the display are described. The optical sensor includes a set of detector elements positioned in a detector plane; a transparent layer; and a set of first reflective surfaces in the transparent layer. Each reflective surface in the first set of reflective surfaces is positioned to receive light from a portion of a sensing region of the display and to reflect the received light. The optical sensor further includes a second set of reflective surfaces, each reflective surface in the second set of reflective surfaces is positioned to receive the transmitted light from the first set of reflective surfaces, and to further reflect the received light towards one of the set of detector elements.