According to example embodiments, a laser optical system includes a laser generator, at least one scan module, an objective lens, a relay lens, a review optical system, and a control device. The laser generator is configured to generate a laser beam. The at least one scan module is configured to reflect the laser beam generated by the laser generator and to direct the laser beam in different directions. The objective lens is configured to focus the laser beam on a substrate. The relay lens is configured to guide the laser beam scanned by the at least one scan module to within an incident range of the objective lens. The review optical system is configured to monitor, in real time, repair of the substrate using the laser beam. The control device is configured to control the at least one scan module.