Product Code: ICAL09_M302

Micro Structuring of Sapphire and Fused Silica by High Speed and High Precision In-volume Selective Laser Etching
Authors:
Martin Hermans, Lehrstuhl Fuer Lasertechnik Rwth Aachen University; Aachen Germany
Jens Gottmann, Lehrstuhl Fuer Lasertechnik Rwth Aachen University; Aachen Germany
Maren Hoerstmann-Jungemann, Lehrstuhl Fuer Lasertechnik Rwth Aachen University; Aachen Germany
Philipp Kramer, Lehrstuhl fur Lasertechnik, RWTH Aachen University; Aachen Germany
Presented at ICALEO 2009

Micro structuring of sapphire and fused silica is an important market e.g. the production of microfluidic devices and sensors that combine optical and microfluidic functions as well as freeform microlense systems. New techniques which enable the processing of sapphire and fused silica are requested. The (in-volume) selective laser etching technique ( I)SLE is a two step process for the micromachining of sapphire and fused silica. First the sample is irradiated using fs-laser direct writing inducing material modifications within the focal volume by non-linear absorption processes. Subsequently the sample is wet etched. The use of high repetition rate fs-lasers, e.g. FCPA lasers with f=0.1-5 MHz, potentially allows for a high productivity, but can not be achieved with nowadays handling systems concerning speed without sacrificing precision and/or numerical aperture. To overcome the limitations mentioned above a scanning optics for fs-laser writing with high precision (x=100-300 nm), high speed (v=100-300 mm/s) and large numerical aperture (NA=0.4-1.2) is developed. New results which are achieved with ISLE/SLE method in combination with the developed scanning optics will be shown and discussed. Furthermore the potential for applications e.g. in microoptics is investigated.