Experimental study on seed light source coherence dependence of continuous-wave supercontinuum performance

We experimentally compare output performance between laser beam (erbium fiber ring laser) and amplified spontaneous emission (ASE) beam (erbium fiber ASE) driven supercontinuums (SCs) in terms of seed beam temporal coherence. We control the degree of temporal coherence of the seed beams by using an optical filter to change their spectral linewidth. The random phase ASE driven SC is found to have better performance than the phase-correlated laser driven SC in terms of spectral smoothness and output power. Significantly high relative-intensity-noise in the output SCs is observed for both cases, i.e. the laser driven SC and the ASE driven SC irrespective of the seed beam temporal coherence due to the nonlinear amplification of quantum fluctuations both in the input pump beam and in the Raman scattering process.