Novel structure of the optical elements to be operated in the long, mid, and near infrared wavelengths of lights is provided. A digital heterodyning technique is disclosed in which a photon detector is sampled at a rate slightly faster than a digitally pulsed excitation signal. The beam of light generated by the light source must be aligned precisely with central axis of the lens and with the photodetector array. The first input is electrically coupled to the first terminal of the first transistor, the second input is electrically coupled to the second terminal of the first transistor, and the first output is coupled to the control terminal of the first transistor. The third conductive region is formed on the second plane.