ABSTRACT
In this paper, we experimentally demonstrate an ultrafast and large nonlinear optical response by controlling the thickness of the GaAs layers in a double hetero-structure through a degenerate four-wave mixing (DFWM) experiment. We show that the polarization corresponding to the second quantized level of the CM state (n = 2) induces a large nonlinear response although this is optically forbidden for ordinal treatment using LWA. We prepare very high quality samples of GaAs layers in order to properly measure the nonlinear optical response of excitons, which extend coherently over the sample. A calculation based on a nonlocal response theory is performed to explain the experimental result.
