Nonlinear Refractive Index of Chalcogenide Glass in the Mid-Infrared Region

The mid-infrared region exhibits various absorption specific to molecular bonds, enabling applications in medical, industrial, and advanced measurement fields. Recent advancements in laser technology have fueled interest in utilizing nonlinear effects within this region. Chalcogenide glass (ChG) has received significant attention broad band mid-infrared supercontinuum (SC) material due to its broad infrared transmission range and high nonlinearity. There are already some works on nonlinear refractive index of ChG [1]–[3]. It is necessary to know the dispersion of the nonlinear refractive index $(n_{2})$ of ChG to perform highly accurate simulation of broad band SC in ChG. However, it has not been clarified in case of ChG to the best of the author's knowledge. We measured the nonlinear refractive index dispersion of a ChG in the mid-infrared region and clarified its effect on the mid-infrared SC.