Broadband supercontinuum generation spanning 1.5-13 μm in Ge11.5As24Se64.5 based chalcogenide glass step index optical fiber

We have reported a design of a step index optical fiber in Ge11.5As24Se64.5 chalcogenide glass. The proposed design of optical fiber is analyzed using full vectorial finite element method. The structure offers a high nonlinear coefficient of 1431 W−1 km−1. Due to this high nonlinearity of the optical fiber a supercontinuum spectrum ranging from 1.5-13 μm is generated in only 10 mm long fiber by applying 50 fs laser secant pulses of 4000 W peak power at the pump wavelength of 3.1 μm. The use of femtosecond pulse laser results in the supercontinuum with high shot-to-shot coherence. Broadband mid-infrared supercontinuum generation has many applications such as in medical diagnosis, food quality control, gas sensing, telecommunication, and optical metrology etc.