1.8–13 μm supercontinuum generation by pumping at normal dispersion regime of As–Se–Te glass fiber

Abstract

AbstractMid‐infrared (MIR) band supercontinuum (SC) light source has highly important application prospects in aerospace, biomedicine, MIR sensing, and pollutant monitoring. As–Se–Te glass has high nonlinear refractive index, wide MIR transmission range and weak crystallization ability. As40Se40Te20 glass fiber is suitable for producing wide MIR–SC spectrum. In this study, purified As40Se40Te20 glass was prepared and unclad and step‐index fibers were drawn. An unclad As40Se40Te20 glass fiber with minimum loss of 1.7 dB/m at 8.8 μm was obtained. By pumping the unclad fiber in the normal dispersion region at 5 μm, we recorded the broadest SC generation spectrum, which covered 1.8–13 μm with a 30 dB spectral flatness, from a fiber with 15 cm length. Besides, As40Se40Te20/As40Se42Te18 step‐index fiber with minimum loss of 5.6 dB/m at 5 μm was drawn from isolation extruded preform. The step‐index fiber was pumped in the normal dispersion region at 5 μm, and the SC spectrum, covering 2.1–11.2 μm with a 40 dB spectral flatness, was recorded from a fiber with 15 cm length. The SC spectrum, which was achieved by pumping the As40Se40Te20 fiber, covered almost all the transparent range of material.