Ultrabroadband mid-infrared supercontinuum generation through dispersion engineering of chalcogenide microstructured fibers

We demonstrate numerically that the use of dispersion-engineered microstrucured fibers made with chalcogenide glasses allows one to generate ultrabroadband supercontinuum spectra in the mid-infrared region by launching optical pulses at a suitable wavelength. As a specific example, numerical simulations show that such a 1 cm long fiber, made with Ge11.5As24Se64.5 glass and pumped at a wavelength of 3.1 mu m using short pulses with a relatively modest peak power of 3 kW, can produce a spectrum extending from 1.3 mu m to beyond 11 mu m ( more than 3 octaves). We consider three fiber structures with microstrucured air holes in their cladding and find their optimum designs through dispersion engineering. Among these, equiangular spiral microstrucured fiber is found to be the most promising candidate for generating an ultrawide supercontinuum in the mid-infrared region. (C) 2015 Optical Society of America