title: Sub-surface channels in sapphire made by ultraviolet picosecond laser irradiation and selective etching.
abstract: We demonstrate the realization of sub-surface channels in sapphire prepared by ultraviolet picosecond laser irradiation and subsequent selective wet etching. By optimizing the pulse energy and the separation between individual laser pulses, an optimization of channel length can be achieved with an aspect ratio as high as 3200. Due to strong variation in channel length, further investigation was done to improve the reproducibility. By multiple irradiations the standard deviation of the channel length could be reduced to 2.2%. The achieved channel length together with the high reproducibility and the use of a commercial picosecond laser system makes the process attractive for industrial application.
authors: Department of Optoelectronic Modules, Fraunhofer-Institut für Angewandte Festkörperphysik (IAF), Tullastrasse 72, D-79108 Freiburg, Germany. ruediger.moser@iaf.fraunhofer.de
authors: Rüdiger
authors: R
authors: Moser
authors: Nirdesh
authors: N
authors: Ojha
authors: Michael
authors: M
authors: Kunzer
authors: Ulrich T
authors: UT
authors: Schwarz
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry* / Q000528:radiation effects*; D007834:Lasers; D008422:Materials Testing; D011829:Radiation Dosage; D013499:Surface Properties
chemical_list: D000537:Aluminum Oxide