The disclosure relates to methods and systems for single-scan line-scan crystallizations using superimposed scanning elements. In one aspect, the method includes generating a plurality of laser beam pulses from a pulsed laser source, wherein each laser beam pulse has a fluence selected to melt the thin film and, upon cooling, induce crystallization in the thin film; directing a first laser beam pulse onto a thin film using a first beam path; advancing the thin film at a constant first scan velocity in a first direction; and deflecting a second laser beam pulse from the first beam path to a second beam path using an optical scanning element such that the deflection results in the film experiencing a second scan velocity of the laser beam pulses relative to the thin film, wherein the second scan velocity is less than the first scan velocity.