Effects of waveguide dimensions on split-core optical waveguide for dispersion and supercontinuum applications

This article presents the theoretical study of a novel chalcogenide optical waveguide. The core of waveguide consists of two D-shaped structures separated by a slab. The cladding is a rectangular slab containing a core within its dimensions. The chalcogenides GeAsSe and GeAsS are considered to be core and cladding of the waveguide, respectively. The dispersion effects and supercontinuum (SC) were calculated for various values of the radius of the top D-shaped core (D) and offset distance (d) from the right end of the bottom core. SC is generated by pumping 50 fs secant hyperbolic (sech) pulses at 1 kW peak power at 3.5 µm as a central wavelength. The maximum wide-spectrum, ranging from 2.2 to 6.5 µm was obtained for D = 1.7 µm and d = 0.4 µm. Increase in ‘d’ leads to a uniform intensity of output SC spectra with sacrificing a small amount of broadening. These results should be useful to create SC sources with uniform intensity as well as broad spectrum in the near to mid-infrared regions.