Generation of nonlinear polarization to emit terahertz waves in above gap states in GaSb/AlGaSb multiple quantum wells

Abstract

In this study, we report the generation of stable even-order nonlinear polarization in the above gap states in strained multiple quantumwells. Using the strain field, the even-order polarization to emit terahertz waves is generated in a zincblende crystal. Our results can make the material and laser choice ranges wide because the exciton resonant excitation is unnecessary.