Mid-infrared supercontinuum generation in multimode step index chalcogenide fiber

In this paper, we propose a design of a high numerical aperture multimode hybrid step-index fiber for mid-infrared (mid-IR) supercontinuum generation (SCG) where two chalcogenide glass compositions As40Se60 and Ge10As23.4Se66.6 for the core and the cladding are selected, respectively. Aiming to get accurate modeling of the SCG by the fundamental mode, we solve the multimode generalized nonlinear Schrodinger equations and demonstrate nonlinear coupling and energy transfer between high order modes. The proposed study points out the impact of nonlinear mode coupling that should be taken into account in order to successfully predict the mid-infrared supercontinuum generation in highly nonlinear multimode fibers.