Sub-picosecond Laser-Driven Shocks in Metals and Energetic Materials

Abstract

A high‐energy sub‐picosecond laser was used both to drive a shock into thin film targets and to spectroscopically interrogate the shocked material. Targets were thin films of molecular materials coated or grown upon thin vapor‐plated metal films on thin glass substrates, or neat metal films on thin glass substrates. The non‐linear optical interaction of the shock‐driving laser with the thin glass substrate produced surprisingly flat shock waves. Sub‐picosecond time‐resolved frequency‐ and spatial‐domain interferometries were used to characterize the shock wave as it transited from the thin metal film into the thin molecular material layer. Overviews of the effect of the pressure‐dependent complex index of refraction of the shocked thin film metal layer, ultrafast interferometric interrogation of shocked molecular materials (examples: glycidyl azide polymer and nitrocellulose thin films), and progress in preparation of, as well as the need for, uniform, well oriented, thin energetic material layers appropriate to such highly time‐resolved methods are presented.