TAPER SHAPES FOR ULTRALOW SIDELOBE LEVELS IN DIRECTIONAL COUPLER FILTERS

摘要

An optical directional coupler filter having atleast two guides; an input guide and a coupled guide. Thespacing between the guides and hence the interactivestrength is tailored so as to provide ultralow sidelobelevels at a narrow spectral bandwidth. A formula has beenderived with respect to the tapered shape function of thewaveguides in order to arrive at the optimum results.