Examination of Possibility of Formation of Aggregated Color Centers in Inorganic Glasses and Their Application to Photochemical Hole Burning

在碱卤化物晶体中，聚集的f中心（如M中心和r中心）表现为光化学孔燃烧（PHB）。如果在无机玻璃中产生聚集的缺氧型点缺陷，我们可以期望在无机玻璃中实现PHB的可能性，而不伴随掺杂染料分子作为PHB中心。在这项研究中，我们用可调激光检测了无机玻璃中聚集色心的形成及其光学吸收带中相关孔的形成。结果表明：(1)铝酸钙玻璃在强还原气氛中熔融后呈现光致变色现象。光诱导EPR得出结论，光致变色中心是一个被Ca^<2+ b>离子包围的电子，即像CaO中的f ^+中心一样被困在氧空位的位置。当激光在4.2K下照射560nm附近的吸收带时，未观察到光谱空穴的形成。(2)通过注入Si^+或p ^+、Si-Si键和中性氧空位，在SiO_2玻璃中产生了两种类型的缺氧缺陷。它们的浓度与注入离子的浓度相容，表明注入离子在底物结构中与氧发生化学反应，留下缺氧缺陷。在这两种缺陷中均未观察到左声子线。

Aggregated F-centers such as M and R-centers show photochemical hole burning (PHB) in alkali halide crystals. If aggregated oxygen-deficient type point defects are produced in inorganic glasses, we may expect a possibility that PHB is realized in inorganic glasses without accompanying doping of a dye molecule as a PHB center. In this study, we examined the formation of aggregated color centers in inorganic glasses and of a pertinent hole in their optical absorption bands with a tunable laser light.The results obtained are summarized as follows :(1) Calcium aluminate glasses melted in strongly reduced atmosphere were found to show photochromism. Light-induced EPR led the conclusion that the photochromic center is an electron trapped at the site of oxygen vacancy surrouned by Ca^<2+> ions, i. e., likeF^+ center in CaO. No spectral hole formation was observed when the laser light illuminated the absorption band centered around 560 nm at 4.2K.(2) Two types of oxygen-deficient defects were produced in SiO_2 glass by implantation of Si^+orP^+, Si-Si bonds and neutral oxygen vacancies. Their concentrations are compatible to those of implanted ions, suggesting that implanted ions react chemically with oxygen in the substrate structure leaving oxygen deficiency defects. No zoro-phonon line was observed for either of these defects.