Photosensitivity and Treatments for Enhancing the Photosensitivity of Silica-Based Glasses and Fibers

Abstract

Due to excellent physical and chemical properties, vitreous silica-based (v-SiO_2- based) glasses prove to be key materials in optical waveguides, metal-oxide semiconductors, and other optical elements. Thus, numerous elaboration methods are used to produce v-silica-based devices. For example, the techniques of vaporphase deposition (e.g., flame hydrolysis deposition (FHD), modified chemical vapor deposition (MCVD), plasma-enhanced chemical vapor deposition (PECVD)) are common in the fabrication of most standard telecommunication silica fibers or planar waveguides [1–4]. Moreover, planar waveguides or thin films can be produced from silica-containing solid source by physical vapor-deposition techniques such as rf reactive sputtering deposition [5–6] and helicon-activated reactive evaporation (HARE) [7]. Waveguides can also be fabricated by means of electron [8] or ion (Si, Ge, Se, O, B, P, or H) implantation in pure silica [9–13]. Furthermore, other processes including sol-gel synthesis [14–15] and conventional melting of raw materials are routinely used to manufacture sol-gel fiber [15], glassy thin films, or multicomponent glass in which waveguides are realized by means of techniques such as ion exchange [16–17].