Photochemical method to produce waveguiding in glass

A photochemical method is described whereby light guiding structures can be directly written with a focused laser beam in a high silica glass that is initially porous. The process mechanism is exemplified using titanocene dichloride as the visible-light sensitive compound impregnated into the porous glass. Examples of the guiding structure realizable from this method are provided. An analysis of the refractive index profile produced by the focused Ar ion laser is given along with a discussion of the limitation of our method.