We have designed a multipulse laser system to measure nanosecond time scale, plasma‐density gradients by moire´ deflectometry. The complete system consists of four, transverse‐excited, atmospheric pressure (TEA) N2laser oscillators and two low‐pressure N2laser amplifiers; two oscillator pulses are injected into a single amplifier. The amplified pulses are less than 1 ns in duration, with a variable, interpulse time of 4–10 ns. As described here, two TEA oscillators and a single amplifier were used to image air‐density gradients in an expanding, air‐shock wave produced by a spark discharge. ©1996 American Institute of Physics.