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中缺陷的光活性。研究了掺锗硅玻璃中锗相关缺陷和光折射率的光化学性质，以及光活性有机-无机杂化材料的研制。掺锗硅玻璃中最具光活性的锗中心是Ge <2+>-，这在很大程度上取决于Ge <2+>-中心的局部结构，其引起光折射率变化的结构重排活化能随着illide结构（高配位结构）形成自由度的增加而降低。在此基础上，采用CVD方法制备了具有高光活性的掺锗硅玻璃薄膜，该薄膜在KrF准分子激光照射下折射率变化为>0 ^<-3>。采用激光辐照直接刻写了更多的e通道波导。采用直接写入技术制备了波导布拉格光栅。含光活性取代基有机硅氧烷的微制备采用光聚合法制备了有机硅氧烷材料的微观结构。制备条件独立控制了硅氧烷主链和有机侧基的聚合程度。利用各种各样的材料和制造参数来设计合成材料的光学特性。有机-无机杂化材料的光热微加工利用激发离子或染料的非辐射声子发射产生的热量，在低熔点透明杂化材料中制备微光子结构。由于所制备的材料具有低于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加工

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