FSR Decrement and Coupling Coefficient Increment in Add-Drop Filters

In this paper, effects of the structural parameters on the opticalcharacteristics of an add-drop filter, consisting of two straightwaveguides and a micro-ring resonator (MRR), have been investigated. Inthis research, effects of MRR radius, the width of MRR and waveguide andthe gap between MRR and waveguide, on free spectral range (FSR) andcoupling coefficient have been studied. It is found that by enhancing thegap and width, coupling coefficient would be increased at first but after awhile it would be decreased. It is also shown that, increasing the radiusand width would decrease FSR. The main goal of this research is todecrease FSR and increase the coupling coefficient of add-drop filters in ajoint state, which are widely used in communication applications

Keywords:

Add-drop filter , Coupling coefficient , Free spectral range , Micro ring resonator