A proximity sensor includes a sensor package having an attachment pad with a radiation source and a radiation detector housed within the sensor package. The source and the detector are held in a fixed relation to the attachment pad, and are mounted by one of a direct or indirect attachment to the attachment pad. A portion of the attachment pad is adapted to form a baffle which forms at least part of an optical isolator. The optical isolator is adapted to substantially prevent the internal propagation of radiation between the source and the detector within the sensor package.