Third-harmonic generation in InAs/GaAs self-assembled quantum dots

We have observed third-harmonic generation associated with intraband transitions in semiconductor quantum dots. The frequency tripling $\left(12\mathrm{}\mathrm{\mu }\overrightarrow{m}4\mathrm{}\mathrm{\mu }\mathrm{m}\right)$ occurs in the valence band of InAs/GaAs self-assembled quantum dots. We show that the third-harmonic generation is enhanced due to the achievement of the double resonance condition between intraband transitions. A third-order nonlinear susceptibility $|{\chi }_{3\omega }^{\mathrm{}\left(3\right)\mathrm{}}|$ as large as $1.5\times {10}^{-14}(\mathrm{m}/\mathrm{V}{)}^2$ is measured for one dot plane.