Optical control of polarity in short electrical pulses generated from coplanar waveguide metal-semiconductor-metal photodetectors

Abstract

We have demonstrated a simple technique to control the polarity of electrical pulses generated from metal-semiconductor-metal photodetectors. By applying the optical beam to different regions of a coplanar waveguide structure incorporating the photodetector, a change in sign of the electrical signal was observed. The signal had an amplitude of 8.5 mV and a full width at half maximum about 150 ps. The results are explained based on voltage induced on the detector electrode.