Numerical Investigation of Supercontinuum Generation Through AsSe2/As2S5 Chalcogenide Photonic Crystal Fibres and Rib Structures

Abstract

We compare numerically the supercontinuum generation (SCG) phenomenon in the Mid-Infrared (MIR) region through AsSe2/As2S5 chalcogenide based optical waveguides namely photonic crystal fiber (PCF) and rib-like structures. The same material combination is used in the two configurations for MIRSCG. Specifically, the studied PCF is composed of a core made of AsSe2 glass and a surrounding cladding made of As2S5 glass while the AsSe2/As2S5 chalcogenide rib waveguide (AsSe2/As2S5-ChRW) is filled in its upper cladding by air while the lower one is constituted by the As2S5 glass. The comparison is conducted in the anomalous dispersion regime on a very short 1 mm-length of propagation for a 50 fs sechtype pulse in the HE11 mode at 4 μm wavelength for each waveguide. Despite the ultra-broadband and coherent MIR-SCG spectrum of 18.75 μm in bandwidth obtained with the considered AsSe2/As2S5-PCF, we found that an AsSe2/As2S5-ChRW that has a height H = 1.98 μm and a width W = 5 μm allows a SCG spanning approximately from 1 beyond 20 μm with a very low energy as 0.4 nJ.