Wavelength selective switching using double ring resonators coupled by a three waveguide directional coupler.
A novel design of a two bus coupled rings 2 x 2 switch with inter ring coupling enabled by a three waveguide (3w) directional coupler is proposed. The device is analyzed using a theoretical model based on coupled mode theory and optical transfer formulae. We show that injected free carriers tuning of the central waveguide in the 3w coupler affects only the bonding resonance mode while the other anti bonding mode is transparent. This feature can be used to perform selective optical switching, and a numerical design example is given on the silicon photonics platform. The selective switch can be employed in a two color duplex bidirectional communication system which conveniently separates the simultaneous transmitted and received signals in a single fiber optic waveguide.
Optics express