Multiple Ruby Laser System For High Speed Photography

Abstract

A multiple ruby laser system is used to provide intense, extremely short (30 ns) highly monochromatic light pulses for high speed photography. The light output from the lasers is transmitted to the two optical systems with fiber optic light guides. The ruby lasers are employed with a conventional Cranz-Schardin system in dynamic photoelastic studies of stress waves and in studies of crack branching in tempered glass. The ruby lasers are employed with an unorthodox Cranz-Schardin system in ballistics studies of armor penetration. Of particular importance is the use of a microprocessor which provides precise synchronization by computing in real time the anticipated arrival time and controlling the Q-switching of the lasers. Variations in projectile velocity due to projectile weight, charge density, and drag are accommodated by programming the microprocessor.