  The use of laser with a Gaussian-beam profile is frequently adopted in
attempts of crystallizing non-single-crystal thin films; however, it merely
results in the formation of poly-crystal thin films. In this paper, selective
area crystallization of non-single-crystal copper(II) oxide (CuO) is described.
The crystallization is induced by laser, laser-induced crystallization, with a
beam profile in the shape of chevron. The crystallization is verified by the
exhibition of a transition from a non-single-crystal phase consisting of small
100 nm x 100 nm grains of CuO to a single-crystal phase of copper(I) oxide
(Cu2O). The transition is identified by electron back scattering diffraction
and Raman spectroscopy, which clearly suggests that a single-crystal domain of
Cu2O with size as large as 5 {\mu}m x 1 mm develops. Provided these
experimental findings, a theoretical assessment based on a cellular automaton
model, with the behaviors of localized recrystallization and stochastic
nucleation, is developed. The theoretical assessment can qualitatively describe
the laser beam geometry-dependence of vital observable features (e.g., size and
gross geometry of grains) in the laser-induced crystallization. The theoretical
assessment predicts that differences in resulting crystallinity, either
single-crystal or poly-crystal, primarily depend on a geometrical profile with
which melting of non-single-crystal regions takes place along the laser scan
direction; concave-trailing profiles yield larger grains which lead to
single-crystal while convex-trailing profiles results in smaller grains which
lead to poly-crystal, casting light on the fundamental question Why does a
chevron-beam profile succeed in producing single-crystal while a Gaussian-beam
profile fails?
