Abstract

Femtosecond laser irradiation in transparent materials is a powerful and straightforward method for the fabrication of optical waveguides. Using this technique, several integrated optical devices have been demonstrated, such as couplers, splitters, and interferometers. At present, such devices are fabricated in a serial way, which means that each waveguide is written after the other. We introduce a novel technique, based on adaptive beam shaping of the femtosecond laser with a Spatial Light Modulator (SLM), that allows the implementation of multiple foci with controlled power distribution and dynamically variable distance. We use this technique for the fabrication of complex integrated optical devices in a single sweep. In particular, we demonstrate multiple parallel waveguides and directional couplers [1]. The writing of one waveguide after the other may result in different optical properties in particular when the distance is small, since the second waveguide is partially fabricated on an already modified region. This aspect can be overcome with our approach.

© 2009 IEEE