Mid-infrared supercontinuum generation by pumping at normal dispersion regime of As-Se glass fiber

In this work, we investigated a new procedure for preparation of purified As-Se glass. After drawing the fibers, an unclad fiber with minimum loss of 2.2 dB/m and a fiber coated with polyether sulfone with minimum loss of 4.2 dB/m were obtained. By pumping the unclad glass fiber in the normal dispersion region at 3 μm, the broadest supercontinuum generation spectrum, covering 1.6 μm to 11 μm with a 40 dB spectral flatness, was recorded from a 15 cm long fiber. The results showed that broadband SC covering nearly almost all transmittance of the material can be achieved with a pump laser in the normal dispersion region.