The propagation characteristic of shock wave front is very important for the research on the power and effect of explosion. A device was developed to measure shock wave speed based on the principle that the insertion loss of fiber curved critically with its minimum radius of curvature increases sharply when pressure is put on it. The principle, configuration, operation process and experimental validation were discussed in detail. Experiment of shock wave from 50g TNT exploder has been carried out, and the mean speeds at 4 specified distances from the explosion center have been measured. The data obtained indicate that the speed gradually reduced with the increased distance from the explosion center, and the results prove that the device based on critically curved fiber loops is practical and effective to measure the shock wave speed. http://www.joa-journal.org/paperInfo.aspx?ID=1844
