Investigation of tellurium-based chalcogenide double-clad fiber for coherent mid-infrared supercontinuum generation

Abstract

Abstract Considerable investigations have been carried out for chromatic dispersion tailoring of chalcogenide glass fiber with various structures and different material compositions. Here we proposed a tellurium-based chalcogenide glass fiber with a dual-clad structure in a W-type refractive-index profile. The structure of the fiber based on Ge-As-Se-Te glasses was numerically analyzed in detail. The simulation results indicate that an all normal dispersion profile can be realized in this tellurium glass fiber with an optimized dual-cladding structure. Then the optimized tellurium chalcogenide fiber with an all-normal dispersion profile was fabricated by multi-extrusion method. Pumping with a 5 μm ultra-short pulsed laser (150 fs, 1 kHz), abroadband supercontinuum (SC) covering 1.5–11 μm can be generated in the 19 cm-long fiber. The coherence of SC was also investigated by numerical simulation. The result shows that a high coherent SC covering 3.5–10.5 μm can be generated in this all-normal dispersion fiber. In conclusion, all-normal dispersion profile can be realized easily in this tellurium-based glass fiber due to their large materials ZDWs.