Semiconductor sieves as nonlinear optical materials

Electrochemical etching techniques were used to fabricate semiconductor sie ves of gallium phosphide, i.e., two-dimensionally nanostructured membranes exhibiting an enhanced optical second harmonic generation (SHG) in comparis on with the bulk material. The SHG rotational and fundamental polarization dependencies studied under sample excitation by a 1064-nm Nd-YAG laser beam indicate optical homogeneity and uniaxial symmetry of the membranes. The a rtificial anisotropy and the enhanced nonlinear optical response induced by nanotexturization make semiconductor sieves very promising for use in all- optical devices. (C) 2000 American Institute of Physics. [S0003-6951(00)025 42-0].