A nonlinear optical device structure is formed by a compound semiconductor having a graded chemical composition such that the average drift velocity of electrons is in the same direction as, but of greater magnitude than, that of holes. In this way, when a pump optical beam (control beam) is flashed (as by a picosecond pulse) upon the structure, electron-hole pairs are created with a resulting temporary spatial separation between the holes and the electron--whereby an electric dipole moment is temporarily induced in the structure. In turn, this dipole moment temporarily modifies either the birefringence or absorption property, or both, with respect to a controlled beam--whereby the polarization, phase, or intensity, of the controlled beam can be modified by the control beam. After the electrons and holes drift to positions which extinguish the dipole the structure is ready for a repeat performance.