Linear and quadratic electro-optic coefficients of self-organized In0.4Ga0.6As/GaAs quantum dots

The electro-optic properties of self-organized In0.4Ga0.6As/GaAs quantum dots have been studied experimentally. Single-mode ridge waveguide structures were grown by molecular beam epitaxy with self-organized In0.4Ga0.6As/GaAs quantum dots in the guiding region. The measured linear and quadratic electro-optic coefficients are 2.58×10−11 m/V and 6.25×10−17 m2/V2, respectively, which are much higher than those obtained for bulk GaAs or quantum well structures. The measured transmission characteristics indicate that low-voltage amplitude modulators can be realized with quantum dot active regions.