一种新型偏振分光棱镜的设计和应用

一种新型的偏振分光棱镜结构,实现了将偏振态相互垂直的光以不同的角度输入后合为一 束的功能,尤其能与双光纤准直器配合使用。通过计算说明二者角度可相互匹配,并分析了在准直器的角度加工出现小的偏差时,通过微量调节输入光束的方向能予以补偿。实验将该棱镜用于偏振光合束器和光学环行器等无源器件中取得了良好效果。     

The indices of refraction of molecular-beam epitaxy-grown Be<Subscript>x</Subscript>Zn<Subscript>1−x</Subscript>Te ternary alloys

We have used a combination of prism-coupling, reflectivity, and ellipsometric techniques to investigate the indices of refraction, n, of a series of Be_xZn_1−xTe thin films grown on InP substrates. After determining the concentrations of each of the Be_xZn_1−xTe alloys using x-ray diffraction measurements, we measured their n at discrete wavelengths using a prism-coupler setup. In addition, we used reflectivity measurements to complement the prism-coupler data and arrive at the dispersion relations of n for the Be_xZn_1−xTe alloys below their fundamental energy gaps. We then employed a rotating analyzer-spectroscopic ellipsometer to measure the complex reflection ratio for each of the films at angles of incidence of 65°, 70°, and 75°. By using the n values obtained from both the prism-coupler and the reflection-spectroscopy techniques to guide the ellipsometric analysis, we were able to obtain accurate results for the dispersion of n for the Be_xZn_1−xTe alloys, not only below their fundamental energy gaps, but also above their energy gaps (up to 6.5 eV) using these three complementary techniques.     

宽调谐窄线宽脉冲钛宝石激光器

介绍了一种采用色散型布儒斯特棱镜扩束器调谐的脉冲钛宝石激光系统，通过泵浦光反馈泵浦，使转换效率提高了～８％；采用色散型布儒斯特棱镜扩束器加光栅（或平面镜）调谐，实现了窄线宽可调谐输出，输出激光能量为２３ｍＪ，转换效率达１９％．调谐范围为６８０～９１３ｎｍ，输出激光线宽小于０．０１ｎｍ。     

高透射比紫外偏光棱镜

报导一种由方解石和氟化钙晶体制成的棱镜在紫外区有非常高的透射比。通过精挑方解石，透射范围可到达０．２１μｍ。     

偏光棱镜视场角的严格分析

本文以格兰·泰勒棱镜为例,给出了任意入射面上的视场角计算公式,分析了视场角与入射面方位的关系,为高精度棱镜的测量和棱镜特征参量的精确标定提供了依据。     

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。     

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.     

用分光计测液体折射率

主要介绍了利用分光计,采用最小偏向法测液体折射率.在测量中使用空心棱镜时是否会对测量产生影响,通过实验证明此方法的可行性.