Influence of the pulse energy on the morphology of waveguide written by use of femtosecond laser

Femtosecond laser light focusing inside transparent glass offers new possibilities for the fabrication of passive or active optical circuits in three dimensional geometries [1]. Examples of couplers, ring resonators or optical sensors fabricated by this way may be found in references [2–4]. Chalcogenide glasses such as As 2 S 3 are very interesting hosts for photowritten structures owing to their high photosensitivity and their wide transparency range from visible to infrared.