We report on high-power operation of a cladding-pumped Er,Yb -doped broadband superfluorescent fiber source in the 1.55 μm spectral region. Over 16 W of single-ended amplified spontaneous emission output was generated employing a simple, all-fiber geometry without the use of a high reflectivity mirror or seed source. The wavelength range spanned from ~1531 nm to 1568.5 nm with a bandwidth (FWHM) of ~17 nm and the corresponding slope efficiency with respect to launched pump power at 975 nm was 30.7%.