Abstract

A large variety of semiconductor samples have been used to generate highly directional, optically steerable, and diffraction-limited ultrafast electromagnetic radiation. Samples have been selected from III-V, II-VI, and group IV semiconductors, including single-crystal, polycrystalline, and amorphous structures. We have compared the optically induced radiated fields from different semiconductor surfaces (interfaces), including an air/semiconductor interface, a metal/semiconductor interface, a p-n junction (solar cell), and a strain-induced piezoelectric layer. In addition, we report the temperature dependence of optically induced electromagnetic pulses. When the surface depletion width was tuned to cross the optical absorption length by varying the sample temperature, a dramatic change of the radiation waveform from the narrow-bandgap semiconductors was observed. We also observed a three-fold rotation symmetry of the radiation from (111)-oriented samples. Finally, we describe the conversion efficiency of optically induced electromagnetic radiation from these samples.

© 1990 Optical Society of America