All-fiber broadband supercontinuum source with high efficiency in a step-index high nonlinear silica fiber

We demonstrate an all-fiber broadband supercontinuum (SC) source with high efficiency in a step-index high nonlinear silica fiber, which was pumped by a 1557 nm subpicosecond-pulse laser in the normal dispersion region. The broad SC spectrum covers the spectral range from 840 to 2390 nm, and the 10 dB bandwidth from 1120 nm to 2245 nm of the SC covers one octave, assuming the peaks near 1550 nm were filtered. The SC source system is constructed by all-fiber components, which can be fusion-spliced together directly with low loss, less than 0.1 dB. Thus the SC source has high energy transfer efficiency from the pump source. The maximum SC average power of 332 mW is obtained, including the peaks near 1550 nm. The spectral density for the 10 dB bandwidth is in the range from -17.3 to -7.3 dBm/nm.