Recent experiments in our laboratories have led to holographic, photolithographic and laser writing techniques capable of patterning Bragg gratings in porous Vycor glass. Photodeposition of Bragg grating on optical fibers composed of fused silica core surrounded a nanoporous sol-gel derived silica has been examined. Gratings with line spacing of 10 jam have been achieved in the cladding of 180μm diameter fibers, and the gratings have been used to inject light into and remove light from the core of the fiber. Equivalent photodeposition experiments have been carried out on square fibers prepared by coating inline a squared core with an equivalent sol-gel based silica. However, attempts to photodeposit a grating failed. Since adsorptivity depends on morphology, the morphologies of the claddings on the round and square fibers have been examined by optical and atomic force microscopy. Surface morphologies have been quantified in terms of surface roughness and correlated with the adsorptivity with respect to Fe (CO){sub}5, the photoactive precursor. Surface roughness and adsorptivity are compared to that of commercially available Coming's code 7930 porous Vycor glass.
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