We propose a new method to estimate the explosive crystallization (EC) velocity (v(EC)) of amorphous silicon (a-Si) films using multi-pulse flash lamp annealing (FLA). This system produces discrete pulses at frequencies of 1-10 kHz to form a quasi-millisecond pulse. The multi-pulses leave behind macroscopic stripe patterns on the surfaces of polycrystalline Si (poly-Si) films, the widths of which are indications of v(EC). We find that catalytic chemical-vapor-deposited (Cat-CVD) and sputtered a-Si films show v(EC) of similar to 4 m/s, whereas the use of electron-beam-evaporated a-Si results in much higher v(EC) of similar to 14 m/s, indicating the emergence of different EC mechanisms. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3602192] All rights reserved.