TRANSIENT NONLINEAR OPTICAL-PROPERTIES OF DELTA-DOPED ASYMMETRIC SUPERLATTICES MEASURED BY PICOSECOND ELECTROOPTIC SAMPLING

We have performed the first picosecond time-resolved measurements of the photorefractive and nonlinear absorptive properties of asymmetric GaAs doping superlattices. The lack of inversion symmetry in these structures results in a net photoinduced electric field and, therefore, photorefractive phenomena via the χ(2) of the material. Using the electro-optic sampling technique, the temporal behavior of the photorefractive, and nonlinear absorption effects are uniquely determined. We have observed peak refractive index changes of 3.8×10-4 at an energy density of 40 fJ/μm2.