光周期的

The influences of decay coefficient of the cavity and the intensity of the field on the phase distribution as well as its fluctuation are discussed.The results show:if there is absence of the phase damping,the phase distribution oscillates with the period π/λ.It presents single leaf at t=nπ/λ,but it splits into multi-leaf construction during the evolution period due to the interaction between the field and the atoms.

结果表明：当腔不存在损耗时，光场相位分布概率以π/λ作周期性振荡；且在t=nπ/λ时刻，光场和原子是退纠缠的，相位分布概率曲线在极坐标图中呈单叶型结构；但在演化周期内，由于光场与原子的相互作用相位分布概率曲线会劈裂为多叶型结构。

A cyclic dynamic magnetizing optomagnetic synchronous magnetic light testing method synchronously imposes a linear polarization cyclic laser narrow pulse train and a cyclic alternating magnetic field to a magnetic sample.

一种周期动态磁化的光-磁同步磁光测试方法，使用线偏振态的周期激光窄脉冲列和周期交变磁场同时作用在磁样品上。

The cyclic alternating magnetic field realizes cyclic and dynamic magnetization of the magnetic sample. After the cyclic laser narrow pulse train reacts with the magnetic sample, polarization of transparent lights or reflected lights of the pulse train will change to measure magnetization variation of the magnetic sample.

周期交变磁场使磁样品被周期动态磁化，而周期激光窄脉冲列与磁样品作用后，由于磁光效应，其透射或反射光的偏振态将发生变化，度量磁样品的磁化变化。

Five novel torsion-mirror optical actuators including double-beam thickness differential structure with single torsional axis, double flexible folded-beam structure with single torsional axis, double-beam vertical torsion comb structure with single torsion axis, four-beam differential compound-micromirror structure with double torsional axis and the combined structure of the four basis forms above, are brought forward. All of these devices could be fabricated by the same silicon micromachining process we have developed. The deformation compensation design with local enhancement for the thin torsional beam which is the key structure of these devices is also put forward to improve the reliability. The three-dimension solid model and two-dimension reduced order model of the torsion-mirror optical actuator are established and then the numerical simulations for evaluating the device characteristics of the statics, dynamics, electrostatic field, mechanical and electrostatic coupling, fluid and solid coupling are carried out to optimize the structure design. Furthermore, three optical fibre clamping structures which could be integrated monolithicly are designed and analyzed to improve the optical coupling capability. 4. Three flexible process flows combined with bulk silicon micromachining and surface silicon micromachining are brought forward to fabricate these novel single-crystal silicon or polysilicon torsion-mirror optical actuators by using the same lithography masks for both SOI wafer and regular silicon wafer. A series of important process experiments are carried out to optimize the process parameters and the process flows. Some novel and typical process phenomena which occurred during the microfabrication are analyzed and then the corresponding solutions are put forward. 5. A MEMS dynamic testing system which exploit blur image synthetic technique, stroboscopic image matching technique, stroboscopic mirau microscopic interferometry technique and microscopic laser dopper vibrometer technique is set up to measure three-dimension and six-freedom micro motions of any MEMS devices with nanometer resolution.

在对硅微机械扭转镜光致动器的光机电特性系统地理论研究的基础上提出了硅微机械扭转镜光致动器的结构设计准则。3、提出了单轴双梁厚度差分结构、单轴双柔性折叠梁结构、单轴双梁垂直扭转梳齿结构、双轴四梁差动复合微镜结构以及以上四种基本结构组合后的衍生结构等五种工艺加工技术兼容的新型的硅微机械扭转镜光致动器，对器件关键结构薄厚度、高耐疲劳扭转梁进行了局部加强的变形补偿设计，建立了器件的三维实体模型以及两维降阶模型，对提出的新结构硅微机械扭转镜光致动器进行了系统的静力学、动力学、静电场、力电耦合和流体固体耦合的建模仿真与优化设计，同时设计并分析了三种可实现单芯片集成的弹性光纤定位夹紧结构。4、提出了组合体硅微加工技术与表面硅微加工技术、兼容同一套光刻版图、可分别基于SOI 晶片和普通Si 晶片、适应于制造提出的各种新结构单晶硅和多晶硅硅微机械扭转镜光致动器的三套柔性加工工艺流程，开展了一系列重要工艺步骤的单项工艺试验，对工艺流程与工艺参数进行了优化，针对加工过程中出现的具有普遍意义的典型工艺问题进行了讨论和分析，并提出了解决方法。5、创新性地将模糊图像合成技术、频闪图像匹配技术、频闪Mirau 显微干涉技术与显微激光多普勒测振技术有机结合，建立起了一套周期运动测量与瞬态运动测量相结合、单点运动测量与全视场运动测量相结合、满足不同MEMS 器件各种动态测试要求的集成的MEMS 三维六自由度微运动精密测量系统。

By utilizing the cross gain modulation effect and the period 1 oscillation harmonic frequency locked in an optically injected semiconductor laser , we can extract the wavelength conversional individual channel optical clock from the optical time division multiplexing OTDM signal .

光注入半导体激光器会产生非线性单周期振荡特性，利用交叉增益调制效应及对单周期振荡的微波锁频效应，可从光时分复用信号中提取出波长转换的分路光时钟。

The result indicates that the output power oscillates and weakens along with increasing input power,and its oscillation period depends on the distance between the medium and beam focal point.Limiter′s limiting ability will decrease if waist size of the incident Gaussian beam and the aperture size increase.With a fixed input power scope,medium′s best limiting position will move towards the focal point if waist size of Gaussian beam and the aperture size increase,but the best limiting position will change a lot with different input power scopes.

结果表明：限幅器的出射功率随入射功率的增加衰减振荡，其振荡周期取决于介质相对于光束焦点的位置；限幅器的限幅能力随入射光束腰半径和光阑孔径的变大而减弱；入射功率范围固定，入射光束腰半径和光阑孔径增大时，介质的最佳限幅位置向入射光束的焦点靠近，但是在某些入射功率范围内会存在多个最佳限幅位置；光限幅器的箝位输出功率随光阑线性透过率的增加存在线性增加和非线性增加两个不同区域，实际应用中应在线性增加区域确定光阑孔径的大小。

We calculated the main effective second order nonlinear optical coefficients of the 〓 quasperiodic superlattice, analyzed the relationship between them and the quasi-periodic structure parameters, studied the extinction phenomenon and the extinction rules in quasi-periodic structure, standardized the expression of frequency conversion in homogenous crystal, periodic and quasi periodic superlattice crystal.

计算了〓准周期超晶格的有效二阶非线性系数，研究了它与准周期各结构参数之间的关系，分析了准周期结构中的消光规律，统一了频率转移效应在均匀材料、周期超晶格和准周期超晶格中的表述。

This project was established based on the first cooperative development of optical in situ real time detecting technique probing the atomic scale layer-by-layer epitaxy growth of oxide film. Over the last three years, we have given full play to the advantages and characteristics of both sides and have finished the assumptions and plans of this subject satisfactorily. 1. In Institute of Physics, we set up advanced oblique-incidence reflectivity difference equipment and wrote one data acquisition procedure that made the simultaneous detection of optical signal and RHEED signal into reality. 2. The first observation of sustained oscillations over hundreds of monolayers in both real and imaginary signals during the epitaxy growth of SrNb0.1Ti0.9O3 on SrTiO3 substrate in LMBE testifies that oblique-incidence is an excellent method to detect and monitor film epitaxy growth real time. 3. For the first time, we verify that oblique-incidence reflectivity difference method can be used to monitor the layer-by-layer growth mode during continuous growth through the correspondence between optical signals to atomic or molecular step edge density on the growth surface. 4. Phenomenological analysis shows that optical signals comprise three parts, the first is proportional to the average thickness of the film and depends on the bulk phase dielectric response; the second is proportional to the coverage of terraces and depends on the dielectric response of atoms or unit cells in the terrace; the third is proportional to the coverage of step edges and depends on the effective dielectric response of atoms or unit cells at step edges. This makes oblique-incident reflectivity difference technique a quantitative macroscopic method to monitor film growth.

中文摘要：本课题是在合作首次发展了氧化物薄膜原子尺度层状外延生长光学原位实时探测方法的基础上立项的，三年来，我们充分发挥双方的优势和特点，圆满完成了课题的设想和计划。1、在物理所建立了一套先进的光反射差法装置，编写了计算机系统的数据采集程序，实现了两路光学信号和RHEED数据的同步采集和显示。2、用激光分子束外延在SrTiO3基底上生长SrNb0.1Ti0.9O3薄膜，首次观测到连续外延几百个原胞层，周期振荡的光反射差实部和虚部信号，证明了光反射差法是一种能原位实时探测与监控薄膜层状外延生长的好方法。3、首次验证了通过对生长表面原子或分子台阶密度的响应，光反射差法可用于原位实时监测在连续生长条件下薄膜的层式生长模式。4、通过唯象理论的研究，证明光反射差信号由三项组成，第一项只与薄膜的平均厚度和宏观光学电介质常数有关；第二项与分子台阶面覆盖度和台阶面上分子层的光学电介质常数有关；第三项与台阶边缘的覆盖度成正比，并和在台阶边缘的分子的有效光学介电常数有关。

Based on noncollinear optical parametric amplification in periodically poled lithium niobate which is realized by quasi-phase matching technology, we consider the possibility of semi-noncollinear phase matching method between collinear and noncollinear geometry.

基于周期性极化铌酸锂晶体的准相位匹配光参变放大过程，通过倾斜周期极化铌酸锂晶体中极化域一定角度，实现了介于共线匹配方式和非共线匹配方式之间的一种半非共线型准相位匹配方式，并以该匹配方式下的各光矢量几何关系得出相位匹配曲线，找到在特定抽运光和信号光波长下能获得宽带增益放大的周期极化长度。

Analytical formulae are presented for the first time to describe the shift in the resonance wavelength of LPG in response to etching of the fiber cladding or a change in the external refractive index. The accuracy of the formula is confirmed by comparision with numerical simulations and experimental results. We demonstrated that the resonance wavelengths of an etched LPG are more sensitive refractive index than those of an unetched grating. The bending properties of long period fiber grating written in different type fiber are studied experimentally. The transmission peaks and the central wavelength of LPG change with the bending of the fiber. A new peak appears at the shorter wavelength when the fiber is being bent. The changes of the peaks are different for different photosensitive fiber. Those properties have broad application foreground in fiber sensors and tunable filters.

分别从理论和实验上对长周期光栅的折射率特性以及光纤包层半径对长周期光栅特性的影响进行了研究，首次给出了描述光纤包层半径腐蚀和外界折射率改变与长周期光栅共振波长关系的理论表达式，实验与理论和数据模拟的结果很好符合，利用腐蚀光纤包层的方法可以有效地提高LPG的折射率灵敏度；对不同光纤中写入的长周期光栅的弯曲特性进行了实验研究，LPG的透射峰形状及其中心波长随光纤弯曲而发生变化，并且随着弯曲将在短波方向出现新的透射峰，其透射峰的变化规律因所用光敏光纤的不同而不同，这一特性在光纤传感和可调谐滤波器方面有重要的应用前景。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。