LASER PEENING PROCESSING APPARATUS AND METHOD OF LASER PEENING PROCESSING

According to one implementation, a laser peening processing apparatus includes a laser oscillator, a condensing lens, an optical element, a liquid tank and a beam expander. The laser oscillator oscillates laser light. The condensing lens condenses the laser light on a surface of an object. The optical element changes a travelling direction of the laser light. The liquid tank inputs the laser light into liquid, and emits and ejects the laser light and the liquid from an exit to the surface. The beam expander adjusts a magnifying ratio of a beam diameter of the laser light entering into the condensing lens. By adjusting the magnifying ratio, a beam diameter of the laser light irradiating the surface becomes a diameter required for laser peening processing of the surface. The adjusting the magnifying ratio also prevents the laser light, having an excess beam diameter, from entering into the optical element.