The 38.5 W spectral combined beam of a 19-element 940 nm diode laser bar has been demonstrated in the spectral beam combining experiment by using a Beam Transformation System (BTS). The outputs had a diffraction-limited beam quality in the fast axis and M2=10.5 in the slow axis. Spectral beam combining was achieved by using an external cavity including a transmission diffraction grating. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.