Experimental and theoretical study of supercontinuum generation in an As2S3 chalcogenide microstructured optical fiber

Alternative materials to silica glass are necessary for supercontinuum (SC) generation at longer wavelengths in the midinfrared (MIR) region. The alternative materials should possess the properties of wide transmission window and high nonlinearity, simultaneously. Chalcogenide glass is the suitable candidate due to its excellent properties of transmission and nonlinearity in MIR region. In this paper, we demonstrate the SC generation in a suspended-core As 2 S 3 chalcogenide microstructured optical fiber (MOF). The variation of SC is investigated by changing the fiber length, pump peak power and pump wavelength. In the case of long fibers (20 and 40 cm), the SC ranges are discontinuous and stop at the wavelengths shorter than 3500 nm, due to fiber absorption. In the case of short fiber as 2.4 cm, the SC range is continuous and can extend to the wavelengths longer than 4 μm. The process of SC broadening is observed when the pump peak power increases from 0.24 to 1.32 kW at 2500 nm in the 2.4 cm long fiber. The variation of SC range with the pump wavelength changing from 2200 to 2600 nm is studied. The selected wavelengths correspond to the dispersion of As 2 S 3 MOF from the normal to anomalous region. The SC generation is simulated by the generalized nonlinear Schrodinger equation. The simulation includes the SC difference between 1.3 and 2.4 cm long fiber at 2500 nm pumping and the variation of SC with pump peak power in 2.4 cm long fiber. The simulation agrees well with the experiment.