Rapidly sequenced pair of two-dimensional images of OH laser-induced fluorescence in a flame

Abstract

A Nd:YAG laser was Q switched twice during one flashlamp pulse and pumped a dye laser, whose frequency-doubled output, tuned to an OH absorption line, illuminated a planar region through a flame. The OH laser-induced fluorescence was focused onto an oscillating mirror, which directed the successive two-dimensional images onto different halves of a vidicon tube. Usable pair separation times of 40 to 180 microsec were obtained. The method has promise for studying changes in small-scale structure in turbulent reactive flows and for instantaneous measurement of the spatial distribution of two observables.