Numerical investigation of tunable Fano-based optical bistability in coupled nonlinear gratings
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
Elservier
Abstract
In this paper, we numerically report the optical bistability based on tunable Fano resonances in
photonic structures consisting of two coupled nonlinear slab waveguide gratings facing to
each other. Quality factor (Q-factor) and asymmetric factor (q-factor) of Fano resonance of the
coupled grating structure can be tuned by changing the gap-distance and horizontal
shifted-alignment. The switching intensity not only depends on the Q-factor, but also strongly
depends on the q-factor of the resonance. Considering strong coupling coefficients and optimizing
the gap-distance between two gratings, the Fano resonance with high Q-factor and optimal q-factor
can be excited. It is found that the horizontal shifted-alignment of the system provides high-order
resonant mode having higher Q-factor and thus reduces the switching intensity than that of the
perfect alignment system. Depending on the wavelengths of operation and q-
factors of Fano resonances, the optical bistabilities will provide various switching intensities.
Description
Keywords
Gratings; Optical bistability; Integrated optics devices