Novel approach for design of low index contrast multimode interference devices

Abstract

2008) Novel approach for design of low index contrast multimode interference devices, Journal of Modern Optics, 55:12, 1913-1921 To link to this article: http://dx.Self-imaging theory is widely accepted as a good method in designing multimode interference (MMI) couplers, but it is also true that self-imaging theory is not suitable for low-contrast structures. An improved self-imaging theory is proposed in this paper for the optimal design of low-contrast 1 Â N MMI couplers. The average effective width of the MMI waveguide and the average effective propagation constant of the MMI waveguide are used in the improved self-imaging theory. An approach is given to find the average effective width. We use this approach in the optimal design of a 1 Â 4 silica MMI coupler, and the results show that the improved self-imaging theory is more accurate than conventional self-imaging theory for low-contrast structures.

MMI-based ultra linear electro-optic modulator with high output RF gain

“…1. It is composed of the input monomode waveguide (zone I), the multimode section (zone II) in which the interference effect of modal fields occurs, and the output monomode waveguides (zone III) [14][15][16]. The basic property of MMI coupler is self-imaging, which is the interference result of the motivated modes in the waveguide .The 1 × 2 MMI coupler splits the light from the input monomode waveguide into two parts with equal intensities and different phases.…”