X-ray diffraction measurements of a femtosecond-laser written waveguides in an YAG single crystal

Miniaturization of optical components is one major task for the further development of high tech equipment. Perfect single crystals or glasses can be structured with femtosecond-lasers. Thus e. g. waveguides can be created and used as laser resonator [1–3]. In order to improve performance it is necessary to obtain detailed information about the local physical properties in the patterned area and its surrounding. While the bulk properties of a crystal are well known it is very difficult to obtain information about basic physical quantities like crystal structure, density and refractive index in the patterned area.