An electro-optic switching circuit is described which will produce a pulse of duration 1 ns or less from a ruby laser. The switch external to the Q-spoiled oscillator cavity, uses a KD*P Pockels cell which is driven by a full-wave voltage pulse. The laser pulse, after *15 amplification, has an energy of 3*10^-2J and is sufficiently coherent and free of jitter to find a ready application in the diagnostics of highly transient plasma.