Spatial Mapping of Transient Atomic Concentrations Using Acousto-Optic Deflection

Abstract

We report a new imaging system for obtaining spatially and temporally resolved atomic absorption profiles for transient events. This is based on an aconsto-optic beam deflector that scans the probe laser beam in one dimension repeatedly across the spatial region of interest. Scan rates of 10 µs durations essentially freeze the absorbing species in time to allow a spatial resolution of 0.06 cm over a 1.2 cm length. With the use of 2K of buffer memory and a digitization interval of 200 ns (12 bits), the time evolution can be followed up to a total of 400 µs. The capabilities are demonstrated in the study of atom formation in a laser-generated plume from a sodium tungstate surface.