Bi代石榴石磁光膜／金属反射层／玻璃多层结构磁光盘的优化设计

从磁光读出和热磁写入两者结合的角度提出一个新的优化目标函数．并用其完成了Ｂｉ代ＤｙＧａＩＧ／金属反射层／玻璃多层结构磁光盘的优化设计。结果表明新优化目标函数更具实际意义。     

磁畴观测方法现状与展望

磁性材料的宏观磁性能主要是由磁畴结构及其运动变化方式所决定,因此磁畴图像的观测是一个很重要的研究课题。目前,磁畴观测的方法已有很多种,如粉纹法、磁光效应法、电子全息法等。本文主要介绍了各种磁畴观测方法的特点及发展状况,与铁磁学、电子信息、磁性材料及器件等学科的关系,指出磁畴观测方法的发展趋势,磁畴实验技术和装置的发展与完善将为磁畴动力学研究提供基础。     

双光楔可控扫描一维轨迹分析

根据几何光学和光的标量衍射理论,对双光楔的折射特性进行了数学分析.研究发现,以相反旋向相同转速旋转的双光楔对光的折射作用等效于一个折射角随2个光楔转角变化的单光楔.在此基础上,对通过双光楔的光束在像面上的衍射光场分布作了理论分析,得到了在夫琅禾费衍射下,光束经转动双光楔在像平面上的衍射光斑随时间变化的规律,从而为一维扫描的可控操作提供了理论指导.     

Transmission-type SPR sensor based on coupling of surface plasmons to radiation modes using a dielectric grating

A transmission-type surface plasmon resonance (SPR) sensor is presented. In the transmission-type SPR structure, surface plasmon waves are outcoupled to radia-tion modes by the use of dielectric grating on a thin-film layer of Ag. Compared with the traditional reflection-type SPR sensor, the new method provides larger detectable range, which might be useful to investigate thick targets such as in cell analysis. Theoretical simulations show that the structures provide high transmission efficiency for surface plasmon resonance and the devices present extre-mely linear sensing characteristics. Furthermore, it is found that the transmission efficiency and the refractive index detection sensitivity of the SPR sensor can be improved by the use of a lower refractive index glass prism.     

光学浮区法生长的GdFeO3单晶

正交钙钛矿结构GdFeO3材料是一种新型的磁光材料。采用光学浮区法生长磁光晶体GdFeO3,通过多次试验,生长出的晶体直径达到8mm,长度为50~80mm,晶体截面抛光后未发现明显的夹杂物等缺陷。测试结果证明光学浮区法是生长GdFeO3磁光晶体的有效方法。     

沃拉斯顿棱镜可见光区减反射膜研制

为了提高镀膜材料和冰洲石基底的附着力以及提高棱镜的透过比,拓宽有效使用带宽,借助于计算机辅助设计方法,设计了高性能多层减反射膜系;选用合适的光学薄膜材料,利用电子束蒸镀,借助于离子源辅助蒸镀,制作了高性能的宽带减反射膜．测试结果表明：e光,o光的平均剩余反射率小于0．5％,有效使用带宽覆盖可见光区;为了改善薄膜和基底问的附着力,采用Al2O3做过渡层。     

单元式偏光分束棱镜分束角和光强分束比

为了研究单元式偏光分束棱镜分束角和光强分束比与棱镜结构的关系,采用从理论上分析o光、e光的分束角和光强分束比与光轴取向、棱镜结构角及入射角的关系,并从实验上测量分束角和光强分束比随入射角变化的方法,进行了理论分析和实验验证,取得了分束角和光强分束比随光轴取向、棱镜结构角及入射角的变化关系的数学表达式,并得到了二者随入射角变化的实验数据。结果表明,在误差所允许的范围内,实验所测的光强分束比和分束角随入射角的变化与理论计算是一致的,且分束角的变化约为入射角的1/2。     

双光楔实现外腔半导体激光器波长精密调谐研究

提出利用旋转双光楔的方法来实现外腔半导体激光器波长的精密调谐.双光楔中,较大楔角的光楔用于粗调,较小楔角的光楔用于细调.与传统的Littman结构光栅外腔半导体激光器相比,通过这种方法,波长的精密调谐无需机械调谐装置,手动即可实现;对调谐的机械要求以及对振动的敏感性降低,波长选择精度相应大大提高.     

分布矩形光束的多棱镜面反射器道路灯具

本文介绍了道路灯具反射器的演变及现状,提出了一种可分布矩形光束的多棱镜面反射器道路灯具的设计原理,并分析其照明质量及低杆安装的可行性,展望了它在道路照明中的应用前景。     

THERMOGENIC PETROLEUM POTENTIAL OF THE NANKAI SUBDUCTION ZONE,OFFSHORE SW JAPAN

In the Kumano forearc basin, offshore SW Japan, the potential occurrence of hydrocarbons has been inferred from both geophysical surveys which point to the presence of natural gas hydrates, and geochemical analyses of gas samples recovered from boreholes and submarine mud volcanoes. The forearc basin is located in the inner part of the Nankai Trough where the Philippine Sea plate is subducting northwards beneath SW Japan. The basin succession unconformably overlies a deformed accretionary prism complex. Hydrocarbons with both microbial and thermogenic origins have been recorded in the Kumano Basin, but the thermogenic petroleum potential is poorly constrained because the regional‐scale geological architecture of the Nankai subduction zone is not well understood. In this paper, the regional‐scale petroleum potential of the Nankai Trough is investigated based on the geological interpretation of new seismic reflection images. The images were derived from legacy seismic survey data using advanced processing techniques such as reverse time migration, which make use of both primary and multiple reflections in wide‐angle seismic data collected with ocean‐bottom seismographs. In the study area, a seaward‐dipping reflector was identified which terminates at the plate boundary décollement and which is interpreted as part of the boundary between previously‐identified older (>14 Ma) and younger (<6 Ma) accretionary prisms. A triangle body at the base of the younger accretionary prism is interpreted to consist of underthrusted sediments including thick hemipelagic mudstones with source rock potential which were scraped off the down‐going oceanic plate. These tentatively identified, deeply‐buried mudstones may have the potential to generate thermogenic hydrocarbons which may then migrate upwards along dipping carrier beds or faults and fractures to the unconformity at the base of the Kumano forearc basin succession. The presence of hydrocarbons in the accretionary prism may be inferred from positive amplitude anomalies which have been identified in the reprocessed multi‐channel seismic data. The new reflection interpretations therefore allow the potential for thermogenic petroleum to be proposed in the study area. The hydrocarbon potential at this subduction margin may therefore rely not only on shallow microbial methane, but may also involve deeper, thermogenic petroleum generated within the underlying accretionary prism.