W. Zapka, P. Pokrowsky, et al.
Optics Letters
We observe that 266 nm laser pulses of 30 ps duration and fluence near 10 J/cm2 causes reproducible surface sputtering and etching of crystalline sapphire in air. The etching rate for the initial ten pulses is relatively slow, 0.04 μm/pulse, producing a smooth surface of the etched area and a broad-angle plume emission. After some 20 pulses, the etching rate is dramatically faster, 0.5 μm/pulse, producing a rough etched surface and a plume composed of broad-angle emission as well as a narrow perpendicular jet emission. Micron-sized depressions can be made on the sapphire with no visible damage or cracking to the surroundings.
W. Zapka, P. Pokrowsky, et al.
Optics Letters
Doug J. Krajnovich, M. Kulkarni, et al.
Applied Optics
A. Schenzle, R.G. Devoe, et al.
Applied Physics B Photophysics and Laser Chemistry
W. Zapka, A.C. Tam, et al.
Microelectronic Engineering