Generation of an ultra-flat, low-noise and linearly polarized fiber supercontinuum covering 670 nm-1390 nm

Abstract

Supercontinuum (SC) generation in all-normal dispersion (ANDi) photonic crystal fibers (PCFs) has recently been investigated due to its ability to generate a low-noise broadband coherent spectrum, with a noise level much lower than typical SC sources based on anomalous dispersion fibers [1] , [2] . Several recent works have however reported some limitations on the input pulse duration due to both stimulated Raman scattering (SRS) and polarization modulation instability (PMI) [2] . Here, using a polarization-maintaining (PM) ANDi PCF pumped by a compact ytterbium-doped femtosecond laser at 1049 nm, we overcome these limitations and demonstrate an ultra-flat octave-spanning (670 nm-1390 nm) coherent SC with excellent low noise (RIN<0.54 % from 700 nm to 1100 nm) and polarization (PER>17 dB) properties. This highly-stable broadband PM-fiber based source could find strong potential applications in biomedical imaging and microscopy where improved signal to noise ratio is essential.