Interferometric laser technique for accurate velocity measurement in shock wave physics

Abstract

An interferometric system for continuously measuring specimen velocity is described. The Döppler shift of a laser beam reflected from the specimen’s free surface is transformed into a variation of the diameter of Fabry–Perot interference rings, and the evolution of the diameter versus time is continuously recorded by a streak camera. Two examples of the use of this system for study of shock waves are given to show the accuracy of this device.