An optical module includes a carrier, a light emitter disposed on the carrier, a light detector disposed on the carrier, and a housing disposed on the carrier. The housing defines a first opening that exposes the light emitter and a second opening that exposes the light detector. The optical module further includes a first light transmission element disposed on the first opening and a second light transmission element disposed on the second opening. A first opaque layer is disposed on the first light transmission element, the first opaque layer defining a first aperture, and a second opaque layer disposed on the second light transmission element, the second opaque layer defining a second aperture.