Fig. 1. Optical layout for the five-channel SBC fiber lasers. Five beams are combined by a diffraction grating with a density of 960  lines/mm. The wavelength-dependent incidence angles can be aligned by means of the steering mirrors. YDFA is the Yb-doped fiber amplifier; CCD is the charged coupled device.

Fig. 2. Spectrum of the combined beam. The smallest wavelength interval is 2.8 nm between 1055.7 and 1058.5 nm.

Fig. 3. Far-field pattern of the combined output beam, mainly maintaining the good beam quality of the incident beams.