An optical proximity sensor includes an optical path extender that extends an optical path length of the optical proximity sensor without a corresponding extension of a geometric path length of the optical proximity sensor. The optical path extender may be a high-refractive index material positioned along the optical path through the optical proximity sensor. The optical path extender may include one or more redirection features configured to change a direction of the light traveling within the optical proximity sensor. The optical path extender may include a photonic component configured to simulate an extension of the geometric path within an optical proximity sensor by applying a momentum-dependent transfer function to the light traveling through it.