A Photochemical Approach to Integrated Optics

Highly resolved refractive index patterns or patterns of iron oxide are obtained by photolysis of (CH₃)₃SnI or Fe(CO)₅ absorbed onto Coming's code 7930 porous Vycor glass followed by consolidation to a nonporous glass. The photochemistries of the molecules on the glass surface, as well as the distribution and relative sizes of the photodeposited metal oxides, are described. Rutherford backscattering, small-angle x-ray scattering, and scanning electron microscopy show that the glass consolidates about the iron oxide particle but not about the tin oxide particle. Tin oxide chemically modifies the glass surface so that it does not consolidate at temperatures as high as 1200°C.