A coaxial opto-electronic transducer adapted for fabrication by integrated circuit techniques is disclosed. A semiconductor light source is disposed on a base member. A support member having a void therein is disposed about the semiconductor light source on the base member. A polycrystalline photoresponsive device is located on the support member proximately the void therein. Light emitted by the light source is reflected from an object in the path of propagation of the light and a portion of the reflected light is directed onto the photoresponsive device. Since the polycrystalline photoresponsive device is on the order of 1 mil in thickness, and is spaced from the periphery of the void in the support member, the support member serves to prevent direct illumination of the photoresponsive device by light emitted by the semiconductor light source.