Chalcogenide microporous fibers for linear and nonlinear applications in the mid-infrared

A new type of microstructured fiber for mid-infrared light is introduced. The chalcogenide glass-based microporous fiber allows extensive dispersion engineering that enables design of flattened waveguide dispersion windows and multiple zero-dispersion points - either blueshifted or red-shifted from the bulk material zero-dispersion point including the spectral region of CO2 laser lines similar to 10.6 mu m. Supercontinuum simulations for a specific chalcogenide microporous fiber are performed that demonstrate the potential of the proposed microstructured fiber design to generate a broad continuum in the middle-infrared region using pulsed CO2 laser as a pump. In addition, an analytical description of the Raman response function of chalcogenide As2Se3 is provided, and a Raman time constant of 5.4 fs at the 1.54 mu m pump is computed. What distinguishes the microporous fiber from the microwire, nanowire and other small solid-core designs is the prospect of extensive chromatic dispersion engineering combined with the low loss guidance created by the porosity, thus offering long interaction lengths in nonlinear media. (C) 2010 Optical Society of America