Surface micro-texture on sapphire fabricated by laser ablation trajectory regulation

Abstract

Fabrication of the surface micro-texture on the C-plane sapphire is undertaken by a 355 nm Ultraviolet (UV) pulsed laser. The surface micro-textures of sapphire with different laser scanning line spacing ranging from 10 μm to 100 μm are obtained, where the selection range of scanning line spacing is controlled in the range of the groove width and plasma width to obtain a surface of high Peak-Valley (PV) value. A reasonable processing order is proposed to manufacture different types of surface micro-textures on sapphire by laser ablation trajectory regulation. In the multiple-passes laser ablation of sapphire by the UV nanosecond pulsed laser, the scanning lines in each direction is treated as once scanning. On this basis, the multiple processing can be carried out to avoid the influence of the subsequent scanning on the machined groove. In addition, the effect of different scanning line spacing on the PV value is quantified and different types of surface micro-textures on sapphire, including the squares, the rhombuses and the hexagons, are successfully fabricated, which can be applied in the friction reduction or anti-reflection field.