We report high-power operation of a broadband superfluorescent source with an all-fiber configuration. The superfluorescent source yields an amplified spontaneous emission (ASE) output of 43.2 and 25.1 W from both ends, respectively. The maximum combined ASE output is 68.3 W with a slope efficiency of 78.6%. The wavelength bandwidths (FWHM) of the counterpropagating and copropagating ASE output are 31.5 and 18.9 nm, respectively. The fused angle-polished side-pumping coupler is applied to set up the all-fiber configuration. Furthermore, the influence of reflectivity on the laser threshold of the ASE sources is studied theoretically. The experimental results agree with the theoretical analysis.