Design and analysis of suspended core channel waveguide made using As2Se3 glass system for mid-infrared supercontinuum generation

Abstract

In this study, we propose a promising 5 mm long air-clad suspended core channel waveguide made of As2Se3 chalcogenide glass for ultra-broadband supercontinuum generation (SCG) in the mid-infrared (MIR). The linear analysis of the proposed waveguide is carried out numerically by considering the potential application of pump sources at three different wavelength regions such as 1.55, 2.8, and 3.5 µm. Among several waveguide geometries analyzed, numerical simulation for SCG at the output of an optimized structure shows that a flat supercontinuum coverage from 1.5 to 15 µm can be predicted using a pump at 3.5 µm with a moderate peak power of 2000 W. To the best of the authors’ knowledge, this would be the broadest spectra in the MIR by the suspended planar waveguide design. In addition, waveguide structural imperfection has also been discussed as it is difficult to control the waveguide dimensions during the fabrication process precisely. The effect of possible deviations along the transverse dimensions is rigorously analyzed and an imperfection among the several deviations is found which could lead to a substantial supercontinuum bandwidth reduction at the waveguide output. Finally, the degree of coherence of the obtained supercontinuum coverage is also tested and it has been achieved nearly coherent spectral outcome from the proposed suspended waveguide design.