A mid-IR source with increased bandwidth using tapered As2S3 chalcogenide photonic crystal fibers

We present simulation results for supercontinuum generation using tapered As2S3 chalcogenide photonic crystal fibers (PCFs). We demonstrate that an increased soliton self-frequency shift can be achieved using a tapered PCF. There is an optimal tapered PCF, which yields an additional 0.4 mu m shift to longer wavelengths relative to the shift that is obtained in an untapered PCF, leading to an increase in the bandwidth from 2.5 mu m to 3.6 mu m. However, the ratio of the output power in the region between 3 and 5 mu m to the input power decreases in a tapered fiber because of the increased fiber leakage loss. (C) 2012 Elsevier B.V. All rights reserved.