Abstract
We report the first bulk frequency tripling in the far-infrared. The experiments are carried out at 20 in the doped semiconductors Ge, Si, and GaAs. Good power conversion efficiency is obtained (). Our arrangement allows an absolute determination of the nonlinear susceptibility (3ω,ω,ω,ω). We show that in the far-infrared, is dominated by free-carrier contributions. Hence, our measurement gives new insight into nonlinear transport properties such as the momentum dependence of the effective mass and of the relaxation time. Furthermore strong changes of (as well as of the absorption) are found to occur at high laser intensity above 100 kW/, which we attribute to carrier heating and hot carrier transfer into higher energy-band minima.
- Received 12 November 1985
DOI:https://doi.org/10.1103/PhysRevB.33.6962
©1986 American Physical Society