Abstract

Usual III-V semiconductors has the strong zinc-blende 43m symmetry that leads to the existence of only one non-linear coefficient (d₁₄) for the second-order susceptibility tensor. Though this coefficient is extremely large one important consequence of the symmetry rules is that second-order processes are forbidden along the three common substrate orientations crystal axes [100], [010] and [001]. This vanishing susceptibility prevents any second-order nonlinear opto-electronic device grown on usual crystal direction GaAs from working in a normal incidence configuration (i.e. with fields propagating along the (001) direction). We demonstrate experimentally that ordered semiconductors, changing the crystal symmetry from the usual zinc-blende for III-V semiconductors to CuPt-type can overcome this limitation.

© 2000 IEEE