An optical proximity sensor is provided that comprises an infrared light emitter an infrared light detector, a first molded optically transmissive infrared light pass component disposed over and covering the light emitter and a second molded optically transmissive infrared light pass component disposed over and covering the light detector. Located in-between the light emitter and the first molded optically transmissive infrared light pass component, and the light detector and the second molded optically transmissive infrared light pass component is a gap. Layers of infrared opaque, attenuating or blocking material are disposed on at least some of the external surfaces forming the gap to substantially attenuate or block the transmission of undesired direct, scattered or reflected light between the light emitter and the light detector, and thereby minimize optical crosstalk and interference between the light emitter and the light detector.