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Two Photon Absorption

The Two Photon Absorption unit at Vienna University of Technology accomplishes new and innovative concepts in the fabrication of waveguide materials and functional biophotopolymers as scaffolds for medical applications.

Lithographic methods generate complexe structures with high resolution.

Nowadays, information technology based on electronic devices is near its physical limits. Smaller integrated circuits and higher clock rates could only be achieved by other techniques. By using photonic technologies e.g. optical fibres, operating speeds of up to several 100 Gb/s have already been reported. Therefore integration of photonic technologies in electronic devices is one of the major goals in information technology today. Integrated waveguides and optical systems have already been established for glass-fiber connections in high-end computers or currently in the backplane for daughtercards in servers, routers and switches. It will be a challenge to integrate this technology in multi-processor boards, motherboards or multichip modules in the near future.

Based on the current project in the framework of the Austrian Nano Initiative with several partners  Jürgen Stampfl from Institute of Materials Science and Technology and Robert Liska from Institute of Applied Synthetic Chemistry at Vienna University of Technology focus on the development of photosensitive refractive index material which can be written by two photon absorption induced processes. Waveguide materials formed by this process and integration in integrated circuits, e.g for mobile phones, is currently one of the main targets of their project.

Two photon absorption induced refractive index change is the ideal technique for real 3D refractive index change in new photosensitive materials currently under development with a resolution well below the micrometer scale. Recently, Stampfl and Liska have shown that it is possible to write parts with wall thickness of ~300nm and a surface roughness below 50 nm with this technique.

Beside the main target of their current project several other promising fields can be utilized by this technique. Preparation of micro- and nanoelectromechanical (MEMS/NEMS) devices, photonic crystals and 3D optical data storage are other relevant applications. This technique would also fit for projects based on the development of biocompatible and biodegradable photopolymers.
The final aim is to explore pathways to print complex models of trabecular bone and vascular systems on demand out of a new generation of biocompatible photopolymers and to equip them with cell selective peptides by a TPA graft technique.

Therefore Stampfl and Liska will especially focus on the selective surface modification of cellular materials at the inner surface, which has not been described until now.