We present experimental results on coherent beam combining from large arrays of high power broad-area semiconductor
lasers. Our laser array consists of 47 high-power anti-reflection coated broad-area semiconductor lasers and each laser
emitter is capable of emitting 1.8 W when uncoated with a maximum array output power of 80W. The total available
power from the AR coated array is approximately 40W. By using an external V-shape cavity design, we experimentally
demonstrated a coherently combined beam at the output power of ~13 W with the 0.07 nm FWHM spectrum linewidth
that is limited by the sensitivity of the optical spectrum analyzer. We also discuss coherent beam combining of highpower
broad area laser diode array in current driver pulse mode operation.