Formation of Periodic Structure in Glasses using Thermal Poring and Laser Irradiation for Optical Applications

研究了热极化条件对熔融石英晶体二次谐波产生的影响。考虑了氧点缺陷、Na^+和H^+等少数物种的作用，并对二阶非线性有源层的厚度、极化过程中的直流电流、透射电子显微镜的微观结构进行了评价。研究了一种新的硫化物玻璃系统RS-Ga_2S_3（R=Ca，Sr，Ba）玻璃的形成区域、物理性质和结构。研究了GeS_2和B_2O_3的加入对BaS-Ga_2S_3-GeS_2和BaO-P_2 O_5-B_2O_3系统玻璃热性能和结构的影响。在这些用于纤维光学的系统中发现了可以拉伸成纤维形式而不结晶的新玻璃组合物。在掺Sm非晶态SrS-Ga_2S_3薄膜中观察到了飞秒激光单次照射引起的微透镜形成。用产生放大锁模钛宝石激光器在金属SmS薄膜中诱导了金属-超导相变。从Ag的光掺杂行为来看，Ge-S、Ge-Sb-S和Ga_2S_3硫化物玻璃可分为两类：（1）含有S-S键和点缺陷的共价玻璃（如，富含S的Ge-S和Ge-Sb-S玻璃）和（2）含有改性剂离子如Ge^2+、Ba^2+和La^3+的离子玻璃（例如，Ge_<40>S_3<60>和Ga_2S_3玻璃）。前一种玻璃仅显示Ag光掺杂，并且适合于通过光进行结构改性以形成平面波导和光子晶体。后一种玻璃对激光辐射具有相对良好的稳定性，可适用于相对高功率的应用，如IR光纤激光器和放大器。

Effect of thermal poling conditions on second harmonic generation in fused quartz was studied. The roles of minority species such as oxygen point defects, Na^+ and H^+ were considered and the thickness of second-order nonlinear active layer, dc current during poling process, microstructure using transmission electron microscopy were evaluated. Glass forming region, physical properties and structure of vitreous RS-Ga_2S_3 (R=Ca,Sr,Ba) were studied as a new sulfide glass system. Effects of GeS_2 and B_2O_3 additions on the thermal properties and structure of BaS-Ga_2S_3-GeS_2 and BaO-P_2O_5-B_2O_3 glass systems were also studied, respectively. New glass compositions which can draw into fiber forms without crystallization were found in these systems for fiber optics. Microlens formation, as induced by single shot of a femtosecond laser pulse, was observed in Sm-doped non-crystalline SrS-Ga_2S_3 thin films. The metallic- to semiconductor-phase transition was induced in metallic SmS thin films by a generatively amplified mode-locked Ti : sapphire laser. From the point of Ag photo-doping behavior, Ge-S,Ge-Sb-S and Ga_2S_3 sulfide glasses can be classified into 2 groups : (1)covalent glasses containing S-S bonds and point defects (e.g., S-rich Ge-S and Ge-Sb-S glasses) and (2)ionic glasses containing modifier ions such as Ge^<2+>,Ba^<2+> and La^<3+> (e.g., Ge_<40>S_<60> and Ga_2S_3 glasses). The former glasses only show Ag photo-doping and are appropriate for structural modification by light for planar waveguide and photonic crystal formations. The latter glasses with relatively-good stability against laser irradiation may be suitable for relatively-high power applications as IR fiber lasers and amplifiers.