New industrial and innovative writing machine for the fabrication of sol-gel TiO2 based sub-micrometric period diffraction gratings

Unique industrial transfer of write on the fly technique, to produce long and large sub-micron period gratings on an industrial and commercial laser beam generator (Dilase 750 from KLOE company) has been successfully achieved. The write on the fly technique, enabling to produce stitchingless long gratings, is based on a continuous interferogram, generated by a high efficiency phase mask, illuminated with a laser beam and projected onto a photosensitive film. As the substrate is continuously moving, the technique is able to write large size gratings, limited by the displacement range of the machine. Demonstration is made on photopatternable solgel thin films (TiO2 xerogel film) on which 600 nm period gratings, several cm long and a few mm wide were written. This demonstration opens the way to cost-effective and rapid demonstrators and extends the possibilities towards high volume products.