Instantaneous measurements of laser-induced plasma shock waves with an optical fiber sensor

High power laser-induced plasma shock waves in air were measured instantane ously with an optical fiber sensor based on detection beam deflection. It w as proved that the time-of-flight deflection angle directly imaged the chan ging rate of the refractive index at the measurement position while a shock wave transmitted the detection beam. This method is suitable for measureme nts of shock waves in transparent flow fields with axisymmetric refractive index distributions. (C) 1999 Elsevier Science B.V. All rights reserved.