Optical nonlinearity enhancement of graded metal-dielectric composite filmsJ. P. Huang1, 2, L. Dong1, 3 and K. W. Yu1
1 Department of Physics, The Chinese University of Hong Kong Shatin, NT, Hong Kong
2 Max Planck Institute for Polymer Research - Ackermannweg 10 55128 Mainz, Germany
3 Biophysics and Statistical Mechanics Group, Laboratory of Computational Engineering, Helsinki University of Technology - P.O. Box 9203 FIN-02015 HUT, Finland
(Received 28 April 2004; accepted in final form 15 June 2004)
We have derived the local electric field inside graded metal-dielectric composite films with weak nonlinearity analytically, which further yields the effective linear dielectric constant and third-order nonlinear susceptibility of the graded structures. As a result, the composition-dependent gradation can produce a broad resonant plasmon band in the optical region, resulting in a large enhancement of the optical nonlinearity and hence a large figure of merit.
77.22.Ej - Polarization and depolarization.
42.65.An - Optical susceptibility, hyperpolarizability.
42.79.Ry - Gradient-index (GRIN) devices.
© EDP Sciences 2004