Large volume ablation of Sapphire with ultra-short laser pulses

The superior optical and mechanical properties of Sapphire (Al ₂ O ₃ ) are highly desirable in various opto-electronics and micro-mechanical applications. However, Sapphire's intrinsic hardness and resistance to most chemicals result in significant processing difficulties. Laser micro-machining is emerging as a promising technology, in particular, the use of ultra-short pulses for material ablation. In this work we investigate and characterize experimentally large volume ablation of Sapphire with femtosecond pulses, and compare the results to previously reported drilling and cutting experiments. We manage to identify optimized parameters for overcoming deleterious thermal effects and debris scattering, and demonstrate high quality 180 μm-deep ablation of 1 mm × 15 mm area in Sapphire.