Asymmetric nonlinear amplitude in patterns of porous silicon

A gradient pattern analysis is used to report a phenomenogical evidence of asymmetric nonlinear spatial distribution of porous silicon structures. We used a canonical sample set obtained from scanning force microscopy. Due to the high sensitivity of the gradient field operator, it is possible to cor relate the photoluminescence performance of porous silicon with different d egree of asymmetries and spatial nonlinearity. A generalization of this new approach to quantify nonlinear amplitude fragmentation in complex lattices is proposed. (C) 2000 Elsevier Science B.V. All rights reserved.