Abstract: The development of a high brightness fiber coupled laser diode module for pumping Ytterbium-doped large-core double cladding fiber lasers was reported. This module was based on high power broad area single emitters which were free space combined in a step arrange manner. The fast axis and slow axis of each diode laser were collimated by micro-lens, and the output beam of diode lasers was combined in the fast axis direction. Then the combined beam was focused using two groups of cylinder lens in the fast and slow axis direction respectively in order to eliminate the spherical aberration. Finally, the combined beam was coupled into an optical fiber. In this experiment, six 976 nm LDs with power of 6 Watts per diode were coupled in a 105 m, 0.15 NA optical fiber. The output power of the fiber coupled module was 29.0 W at operating current of 6.2 A. The coupling efficiency reached 80.1%, and the brightness exceeded 4.74 MW/cm2-str.