Investigation of photo-activity of glasses 〜from the electronic and vibrational structures〜

本研究的目的是从电子和振动结构的角度研究玻璃缺陷的光活性。开展了Ge掺杂石英玻璃中Ge相关缺陷和光折变的光化学研究以及光活性有机-无机杂化材料的开发。 1．掺Ge石英玻璃中Ge相关中心的光活性和增强的光折变性在石英玻璃中发现最具光活性的Ge相关中心是Ge^<2>，这在很大程度上取决于Ge^<2>中心的局域结构，其导致光折射率变化的结构重排的活化能随着伊利德结构（更高配位结构）形成自由度的增加而降低。在此基础上，采用CVD法沉积了高光活性的Ge掺杂石英玻璃薄膜，该薄膜在KrF准分子激光照射下表现出>10^-3>的折射率变化。通道波导是通过激光照射直接写入的。采用直写技术制作了波导布拉格光栅。 2．含光活性取代基的有机硅氧烷的微制造通过光聚合在有机硅氧烷材料中制造微结构。硅氧烷主链和有机侧基的聚合度由制备条件独立控制。使用各种材料和制造参数设计所得材料的光学性能。3．有机-无机杂化材料的光热微制造利用激发离子或染料的非辐射声子发射产生的热量，通过光热过程在低熔点透明杂化材料中制造微光子结构。由于要制造的材料具有低于 200℃ 的低熔点，因此可以使用小于几 mW 的极低功率激光源进行微制造。

The purpose of the present study is the investigation of photo-activity of defects in glasses from view points of electronic and vibrational structures. The photo-chemistry of Ge-related defects and photorefractivity in Ge-doped silica glasses and development of the photo-active organic-inorganic hybrid materials were carried out.1. Photo-activity of Ge-related centers and enhanced photorefractivity in Ge-doped silica glassesThe most photo-active Ge-related center was found to be Ge^<2+> in silica glasses, which largely depends on the local structure of the Ge^<2+>-centers, whose activation energy of structural rearrangement responsible for photorefractive index change decreased with increasing the degree of freedom for the formation of illide structure (higher coordination structure). On the basis of the obtained results, highly photoactive Ge-doped silica glass thin film was deposited by CVD method, which exhibited >10^<-3> refractive index change by KrF excimer laser irradiation. Th … More e channel waveguides were directly written by laser irradiation. The waveguide Bragg grating was fabricated the direct writing technique.2. Micro-fabrication of organosiloxane containing photo-active substitutentsMicro-structures were fabricated in organosiloxane materials through photo-polymerization. The degree of polymerization of siloxane main chain and organic side group was independently controlled by the preparation conditions. Optical propoerties of the resultant materials were designed using the wide variety of material and fabrication parameters.3. Photo-thermal micro-fabrication of organic-inorganic hybrid materialsThe micro photonic structures were fabricated in the low-melting transparent hybrid materials through photo-thermal processes using heat generated by nonradiative phonon emission of excited ions or dyes. A very low power laser source less than several mW can be used for the micro fabrication because the materials to be fabricated exhibited low-melting point less than 200℃ Less