High repetition rate mid-infrared supercontinuum generation from 1.3 to 5.3 mu m in robust step-index tellurite fibers

We demonstrate broadband supercontinuum generation over two infrared octaves, spanning from 1.3 to 5.3 mu m, with an output power of 150 mW in robust step-index tellurite fibers with core diameters between 3.5 and 4.3 mu m. As a pump source, we use femtosecond mid-IR pulses from a home-built post-amplified optical parametric oscillator tunable between 1.5 and 4.0 mu m at a 43 MHz repetition rate. We study the influence of core size, pump wavelength, and fiber length to optimize the spectral bandwidth. A key requirement for efficient spectral broadening is a low and rather flat average anomalous dispersion over a wide spectral range that can be tailored accordingly by changing the fiber core diameter. Numerical simulations based on the generalized nonlinear Schrodinger equation are in good agreement with experimental results. (C) 2017 Optical Society of America