Laser writing of optical waveguides in sol-gel films

Laser heating can be used to fully densify selected areas of a partially densified sol-gel film deposited onto a glass substrate, thus substituting the conventional heat treatment in an oven. Here the topographic and optical characteristics of strip waveguides produced in a SiO2-TiO2 film by direct writing with a focused CO2 laser are presented, and the critical parameters of the process discussed.