Self-guiding multimode interference threshold switch

We propose a new passive optical thresholding device that combines the prin ciples of multimode interference (MMI) with self-guiding. The multimode reg ion is composed of a nonlinear optical material that will support a self-gu ided beam (i.e., a material with a positive Kerr nonlinearity). The device operates by switching between the MMI mode of operation and the self-guidin g mode of operation, depending on the input light intensity. We describe th e basic principles of a self-guiding MMI device, simulate the device, and d iscuss design issues associated with these optically controlled optical swi tches. (C) 2000 Optical Society of America.