Nobu Kuzuu

Optical Properties of Soot Remelted Silica Irradiated with Excimer Lasers

Characteristics of ArF laser induced luminescence, and absorption bands in soot remelted silica, before and after annealing in various atmospheres, were investigated. A soot remelted silica containing no OH has an absorption band at 5.1 eV which can be annealed out with H 2 , but an absorption band at 5.8 eV is induced by subsequent the ArF laser irradiation. In a soot remelted silica containing 50 ppm of OH, an emission band at 1.9 eV was induced by the ArF laser irradiation. The 1.9 eV band can be annealed out with He and H 2 , but, by annealing in H 2 , the 5.8 eV absorption band was induced by the ArF laser irradiation as in the case of the silica containing no OH.

Excimer Laser Induced 5.8 eV Absorption and 1.9 eV Emission Bands in Fused Silicas

Characteristics of ArF excimer laser induced 1.9 eV emission and 5.8 eV absorption bands in type III and soot remelted silicas were investigated. In a type III silica synthesized in a reducing condition, an absorption band at 5.8 eV band is induced. The creation of this band can be prevented by annealing in an atmosphere of He. In the soot remelted silicas with and without OH, the creation of the 5.8 eV band is strongly promoted by annealing in H2. An emission band at 1.9 eV is induced in a type III fused silica synthesized in an oxydizing condition and soot remelted silica containing OH. When annealing in He, creation of the 1.9 eV band is strongly promoted in the former but suppressed in the latter sample. This difference is derived from the difference of higher order structures between the type III and the soot remelted silicas.