Nonlinear directional couplers (NLDCs) with a variable coupling coefficient (VCC) in self-focusing and self-defocusing materials are investigated. Specifically, the Gaussian type VCC NLDCs are studied in detail. The results show that the responses of the VCC NLDCs on self-focusing and self-defocusing materials are different, especially when input power is high. The coupled-mode theory can also be used to predict the characteristics of the VCC NLDC on self-focusing material, even when input power is high.
© 2003 Optical Society of America
(130.3120) Integrated optics : Integrated optics devices
(130.3130) Integrated optics : Integrated optics materials
(130.4310) Integrated optics : Nonlinear
(230.1150) Optical devices : All-optical devices
Gang J. Liu, Bin M. Liang, Qu Li, and Guo L. Jin, "Variable Coupling Coefficient Nonlinear Directional Couplers with Self-Focusing and Self-Defocusing Nonlinearity," Appl. Opt. 42, 4315-4319 (2003)