Intense terahertz emission from surface-illuminated GaAs grown on Si(100) and Si(111) substrates
Abstract
We present results on the generation of terahertz radiation from femtosecond laser-irradiated GaAs layers grown on Si(100) and Si(111) substrates. Results show that the terahertz emission is an order of magnitude stronger than that of a bulk GaAs wafer. GaAs layers grown on Si(100) appear to have stronger emission compared with their Si(111) counterpart although the disparity is not very significant. This enhancement to the GaAs-related emission is presently ascribed to the strain field at the GaAs/Si interface. These results show proof of concept on the feasibility of terahertz optoelectronics being integrated into the existing semiconductor technology.