Abstract: A crystallization apparatus for crystallizing a semiconductor layer formed on a substrate. The crystallization apparatus includes a laser generator, which generates a laser beam, an optical device for changing a path of the laser beam emitted from the laser generating device, and a stage on which the substrate is arranged, wherein the optical device changes the path of the laser beam by rotating with respect to a constant axis, and the stage is moved so that the laser beam having the changed path is irradiated to a constant region on the semiconductor layer.

Abstract: An optical module for irradiation of laser beams includes a mirror mount, a rotation shaft coupled to a center of the mirror mount, a vibration member coupled to one end of the mirror mount and the vibration member vibrating the end of the mirror mount in front-and-rear directions, a mirror fixed to the mirror mount and the mirror irradiating laser beams by performing reciprocal rotational motion with the mirror mount with respect to the rotation shaft, and a weight arranged on at least one of a first side and a second side of the mirror mount. The weight is interposed between the rotation shaft and the at least one of the first side and the second side to compensate concentricity of the mirror.