Low-Noise Supercontinuum Using a $1.85 \mu \mathbf{m}$ fs Pump and a Normal Dispersion ZBLAN Fibre

Extremely low-noise supercontinuum (SC) can be generated using a polarisation-maintaining (PM) all-normal dispersion fibre and a femtosecond (fs) pump [1]. These low-noise SC sources have enabled applications such as shot-noise-limited SC-based ultra-high-resolution optical coherence tomography [2], and broadband scanning near-field optical microscopy [3] in the near-infrared. The specific requirements needed in the advancement of low-noise SC sources have been made possible by the the maturity of silica optical fibre technology and ultrafast erbium (Er) lasers. In this work we have investigated the possibility of extending the low-noise SC into the technologically less mature mid-infrared (MIR) wavelength region.