US Patent 11629948 Optical interferometry proximity sensor with optical path extender

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.