非谐振腔型KTP光参变振荡器

研究了双晶体走离补偿、非谐振腔型KTP光参变振荡器，利用一套膜片实现了KTP相位匹配所允许的全波段调谐，信号光调谐范围0.698μm-1.026μm，闲频光调谐范围1.105μm-2.237μm。5倍阈值处，信号光840nm最高输出能量53mJ，能量转换效率25.8%，量子转换效率40％，闲频光的量子郊率也达到32％。     

Solutions for a Mode Ⅲ Growing Crack in a Piezoelectric Plane Under Two Kinds of Electric Boundary Conditions ＊

The solutions for a mode Ⅲ crack growing along an arbitrary propagation path in a piezoelectric plane are studied under the impermeable surface condition and the electrical contact surface condition respectively. According to the two kinds of electric boundary conditions, the Hilbert and Riemann boundary value problems in a half-plane including opening smooth arc are obtained from the theoretical analysis. Moreover, the equipollence of the solution formed under these two electric boundaries is proved, and unified solutions for the stress and electric displacement distribution in the crack-tipfield of the piezoelectric plane are achieved.     

A Fully Vectorial Effective Index Method for Accurate Dispersion Calculation of Photonic Crystal Fibres

A fully vectorial effective index method is developed for accurate dispersion calculation of photonic crystal fibres （PCFs）. In order to improve the accuracy of the model, different values for the effective core radius are used when PCFs have different fibre parameters. The accuracy of our approach is demonstrated by comparing our results with other numerical and experimental results reported in literature. It is found that the accuracy of the fully vectorial effective index method is improved and our results agree well with accurate numerical results obtained by other methods as well as the previously reported experimental data.     

X射线晶体谱仪的设计

分析了Z箍缩等离子体的辐射特性;介绍了用平面晶体作为分光元件的X射线晶体谱仪的原理、结构参数设计及性能分析;对晶体谱仪测量X射线辐射谱的初步实验进行分析,给出预估的实验结果。     

Spatially Inhomogeneous Gain Modification in Photonic Crystals

The electric and magnetic energy distributions in photonic crystals （PC） are calculated by using the plane wave expansion （PWE） method. Even though the total electric and magnetic energy in each unit cell of photonic crystals are equal to each other, the ratio of electric and magnetic energy densities varies depending on the local position. Based on Fermi＇s golden rule, the optical gain is analysed in the full quantum framework that takes the nonuniform energy density ratio into account. This nonuniform energy density ratio in photonic crystals, defined in an equal form as gain modification factor, leads to spatially inhomogeneous modification of optical gain. Results reported in the paper provide a new perspective for analysing gain characteristics, as well as the lasing properties, in photonic crystals.     

Design of Two-Dimensional Photonic Crystal Edge Emitting Laser for Photonic Integrated Circuits

An edge emitting laser based on two-dimensional photonic crystal slabs is proposed. The device consists of a square lattice microcavity, which is composed of two structures with the same period but different radius of air-holes, and a waveguide. In the cavity, laser resonance in the inner structure benefits from not only the anomalous dispersion characteristic of the first band-edge at the M point in the first Brillouin-zone but also zero photon states in the outer structure. A line defect waveguide is introduced in the outer structure for extracting photons from the inner cavity. Three-dimensional finite-difference time-domain simulations apparently show the in-plane laser output from the waveguide. The microcavity has an effective mode volume of about 3.2（λ/nslab）^3 for oscillation mode and the quality factor of the device including line defect waveguide is estimated to be as high as 1300.     

热效应对光折变晶体两波耦合的特性影响的理论分析

用一种模型对两波耦合进行了分析，导出了强度相位的解析式，对影响两波耦合的参数进行了理论分析。分析了对ＢａＴｉＯ３光折变晶体的两波耦合的测量结果。     

双折射双频激光器偏振特性的分析

用激光原理和晶体光学原理分析了腔内加旋光晶体的激光器输出光的偏振特性，实验和分析表明，激光器输出两束不同频率的垂直线偏振光，激光器两端输出光的偏振面有一夹角ａ，且此夹角与晶轴和传光方向的夹角θ有关。理论计算结果在双折射双频激光器的实验结果符合很好。     

氙灯泵浦新型晶体Nd∶S－VAP调Q激光器腔内倍频研究

采用氙灯泵浦晶体Ｎｄ∶Ｓ－ＶＡＰ，ＫＴＰ晶体腔内倍频，实现了Ｎｄ∶Ｓ－ＶＡＰ晶体０．５３２５μｍ绿光激光ＢＤＮ染料片调Ｑ运转。测量了输出绿光激光的特性及不同腔长和染料片小信号透过率情况下的输出能量及脉冲宽度，给出了染料片调Ｑ腔内倍频的耦合波方程组，数值求解方程组，所得的理论数据与实验结果很好地相符