The issue of laser damage to potassium dihydrogen phosphate (KDP) crystal is an important factor restricting the development of high-power laser facilities for inertial confinement fusion (ICF) such as the National Ignition Facility (NIF) in the United States, the Laser MegaJoule in France and the Shenguang Laser Facility in China[1–4]. Laser damage sites on the surface of optical components would reduce their resistance to high power lasers, accelerate the scrapping of components and deteriorate the quality of laser beams[5,6]. For high-cost optics like KDP crystal, NIF proposed a ‘recycling’ strategy to mitigate the growth of laser-induced surface damage and maximize its lifetime[7,8]. The main method uses an optics damage inspection system to determine whether laser damage to the optics surface has occurred[5,9]. Tiny defects such as surface fractures and laser ablation would then be replaced with specific smooth contours[7,10]. It is a very effective and feasible method for improving laser damage resistance of optical components during subsequent laser irradiation.