High-Power Flat Supercontinuum Generation by Using UHNA7 Fiber With Spectrum of 1.77-3.31 μm

In this work, we demonstrated a high-power flat mid-infrared (MIR) supercontinuum (SC) source based on a piece of UHNA7 fiber which pumped by a flat 1.9-
$2.6~\mu \text{m}$
SC source. The SC spectrum with a coverage of 1.77-
$3.31~\mu \text{m}$
and a maximal average output power of 12.01 W was obtained by optimizing seed pulse parameters and UHNA7 fiber length. The 5 dB spectral bandwidth of SC spectrum was close to ~1000 nm, spanning 1925 to 2894 nm. To the best of our knowledge, this is a MIR SC source that combines high-power and flatness based on low GeO2 doped fiber to date. Furthermore, we investigated the SC power stability, corresponding to the root-mean-square (RMS) value of 0.074% in 1 hour. The set-up has an all-fiber structure and therefore offers excellent portability and stability, making it an ideal light source for fiber optic sensing and spectral imaging technology.