光子

In order to reduce the dead time and enhance the counting rate of single photon avalanche detector with higher quantum efficiency , we design a flexible and chronometrical circuit which realizes the excellent active technology with active quenching and fast reset.

该技术使探测器工作在更加安全高效的模式下，最后实验测得探测器总的死时间由原全被动模式下大于2us缩短至120ns，单光子计数率由被动中低于1MHz上升到8MHz以上，因此可以满足一些高速光子计数的需要。

A new type of high-birefringence photonic crystal fiber is brought forward, and the method introducing circinal holes with different sizes or elliptical holes which is used to design high-birefringence photonic crystal fiber is replaced by introducing fluorine-doped solid circles.

提出了一种新结构的高双折射光子晶体光纤，通过引入掺氟实心圆的方式形成双折射，而不采用大多数高双折射光子晶体光纤中引入不同孔径空气孔或椭圆空气孔的结构。

The lower PBG exists in one third of the first Brilloin zone while the upper one can appear, simultaneously and complimentarily, in the rest two thirds of the first Brillouin zone.

低频光子带隙在1/3布里渊区内存在，而高频的光子能带在另外的2/3布里渊区内存在。

In this thesis, we investi-gated some typical production processes related to chargino and neutralino viaelectron-positron, photon-photon and hadron-hadron collision at futural Linear Colliders and Large Hadron Colliders, and gave the analysis and discussion of both the radiative corrections and CP violating effects. To reach the required precision, we performed the calculation beyond the tree level. From the calculation we can conclude that the physical signals arising from charginos and neutralinos are considerable, both in direct production and indirect search process.

在本文中，我们研究了在未来的直线加速器和大型强子对撞机上通过电子正电子、光子光子和强子强子对撞与chargino，neutralino相关的一些典型过程，并给出了辐射修正和CP破坏效应的分析讨论，为了达到所要求的足够的精度，我们进行了树图阶以上的计算，通过计算我们可以得出结论，无论是直接产生还是间接寻找过程，来自chargino和neutralino的物理信号都将是显著的。

A photonic crystal-air interface or line defect is utilized as a holophote or a partial reflective mirror to design a paralleled plane cavity, a single ring cavity structure and a multi-ring cavity structure. The method has simple design idea, good integration and wide application; by adopting the method, the self aligning photonic crystal lasers with different wave bands can be designed according to the luminescent characteristics of different materials; particularly, the utilization of semiconductor materials to design a light source of optical communication wave bands has more important practical value.

利用光子晶体-空气界面或线缺陷作为全反射或部分反射镜设计平行平面腔、单环形和多环形腔结构；该方法设计思路简单，集成性好，适用范围广，可根据不同材料的发光特性设计不同波段的自准直光子晶体激光器，特别是用半导体材料设计光通讯波段的光源器件具有更重要的实用价值。

For these states, I study the mean photon number distribution and their non-classical properties, which are photon antibunching, violations of Cauchy-Schwarz inequality and two-mode squeezing. Insection 4, I extend uncorrelated two-mode SU(1,1) coherent states to the multi-mode SU(1,1) coherent states.

对这些态，我们研究了平均光子数分布及其非经典特性，它们包括光子聚束，Cauchy-Schwarz不等式的违背和双模压缩。

Multibranched porphyrin ; two-photon absorption ; two-photon fluorescence ; intramolecular energy transfer

卟啉多枝分子；双光子吸收；双光子荧光；分子内能量转移

The enhanced two-photon absorption found in these chromophores was attributed to the fact that the multibranched chromophores had both an extended π-conjugated system and an increased intramolecular cooperative effect compared to the one-branched chromophore.

这些多枝结构化合物的双光子吸收截面较大，双光子吸收增强来源于多枝分子中扩展的π共扼体系和重复单元的协同效应。

The main idea is to lift the band degeneracy at high symmetry points in the Brillouin zone of crystals by lowering the structure symmetry of crystal. One way is introducing nonspherical atom configurations, another is introducing anisotropy in atom dielectricity.

设计的核心思想是通过降低光子晶体结构的对称性，消除光子能带在晶体的布里渊区高对称点上的本征简并，以获得完全的带隙我们采用两种方法，一种是将晶体的原子做成非球对称，另一种用各向异性的颗粒球做晶体原子。

PBG structures with a nonspherical atom configuration can also exhibit complete band gaps in fcc and bcc lattices, when the atoms are arrayed along a certain direction.

能带计算还表明，面心立方、体心立方结构的非球形对称颗粒的光子晶体，当原子取向合适时，也能够形成完全的光子带隙。

Shop assistant: Please check at the door.

店员：请您到门口柜台交费。

In the end, transportation of PAHs in the environmental matrix was preliminarily investigated and discussed according to PAHs data of soils and sediments from a certain region in Shanghai. The result indicated that there are two or more pathways on PAHs transportation in the environmental matrix.

最后，对上海特定地区内PAHs在环境介质中的迁移径途进行了分析讨论，结果表明上海市土壤和沉积物等环境介质中PAHs的迁移存在多种途径。