High energy laser beam steering with periodic shock waves

Abstract

Atmospheric density gradients bend light as can be seen with naturally occurring mirages. Shock waves also produce density changes that bend or refract light. While a single shock front from a supersonic projectile refracts light only on the order of hundreds of arcseconds, theoretical results indicate that beam deflections of thirty or more degrees are possible from periodic shock waves. Two types of idealized plane periodic shock waves are analyzed. A ballisticsderived periodic shock wave based on empirical data from projectile firings and a synthetic-derived periodic shock wave based on a tradeoff between peak pressure amplitude and shock wave period required to produce a target density gradient. Predicted laser beam refractions from both types of idealized plane periodic shock waves are presented. Predicted laser beam steering angle versus peak pressure for fixed period synthetic-derived periodic shock waves is presented. Predicted laser beam steering angle versus shock wave period for fixed peak pressure amplitude syntheticderived periodic shock wave is presented.