基于高阶厄米高斯模倾角测量

本文主要对高阶厄米高斯模式的倾角测量进行了理论分析,提出了利用高阶厄米高斯模式可以进一步提高倾角测量的方案,并对不同模式进行倾角测量的精度进行了对比。计算结果表明,采用的模式的阶数越高,倾角测量的精度越高,这一结果为进一步提高倾角测量实验提供理论依据。     

可调谐PPLN中红外光参量振荡器失调特性

通过对晶体进行周期调谐,实现了中红外参量光输出,在此基础上研究了晶体移动、腔镜偏转等对失调特性的影响。结果表明：由于PPLN通道的小尺寸波导特性和参量振荡特性,其失调特性不同于常规激光器。PPLN晶体沿不同轴移动的功率变化曲线有不同的特点,沿x轴移动的失调容限大于沿y轴移动的失调容限;腔镜的失调容限与腔镜偏转方向有关,腔镜横向偏转的失调容限大于纵向偏转的失调容限;PPLN晶体温度和通道对失调容限几乎没有影响。     

Electrooptic study of antiferroelectric mixtures for display application

The aim of this paper is to study the influence of electric field on alignment of para-, ferro- and antiferroelectric phases in the vicinity of SmA^* — SmC^* or SmC^* — SmC _A ^* phase transitions as to obtain mono-domain cells. Four mixtures studied (W-193B, W-193B-1, W-201, W-204D) show the SmC _A ^* phase in a wide room temperature range. Measurements of the spontaneous polarization versus temperature by using reversal current method give an answer to the question, what kind of the transitions take place between para-, ferro- or antiferroelectric phases using the Landau mean field theory. Optimal electrooptic parameters for different compositions of the mixtures such as tilt angle, spontaneous polarization and saturation voltage have been measured to compare parameters of the mixtures studied.     

Gain characteristics of a 210 km hybrid Raman/erbium-doped fiber amplified loop

As an alternative to using gain flattening filters or other optical devices that add attenuation to balance the gain in the optical spectrum, we have studied the effects of combining gain from Raman amplifiers and erbium-doped fiber amplifiers (EDFAs) in a fiber recirculating loop. We have shown a parameter range for which the gain profile is flat, and have analyzed the variation of the gain tilt as a function of the individual contributions of the Raman and EDFA amplifiers.     

Pulse-front tilt created in misaligned dispersionless optical systems and correct interferometric autocorrelation

In this work we present a matrix analysis of the sensitivity of otherwise dispersionless 4f and 2f-2f optical systems to misalignments resulting in spatio-temporal distortions of ultrashort laser pulses. Special attention is given to the possible creation of a pulse-front tilt (PFT). The exact analytical expression for the second-harmonic interferometric autocorrelation signal of an inverted-field autocorrelator is calculated. It confirms the effective broadening of the ultrashort pulses in the presence of an arbitrary PFT.     

测试基准倾斜对辨识加速度计数学模型精度的影响

建立了考虑测试基准倾斜时加速度计的数学模型。用初始安装误差角辨识理论及算法，在一定范围内消除或减弱了测试基准倾斜对加速度计数学模型辨识精度的影响。该方法可以降低对测试设备地基和调平装置精度的要求，降低其测试和标定成本，提高测试工作效率。     

虚共焦非稳腔腔镜倾斜对激光传输的影响

首先用几何光学方法分析了虚共焦非稳腔腔镜倾斜引起的准直光线偏离光轴,形成偏斜光线的角度灵敏度和偏斜距离灵敏度同非稳腔放大率ｍ和腔镜倾斜角β之间的关系,然后用Ｃ－６程序计算、分析了柱面条状虚共焦非稳腔单镜、双镜反向和同向倾斜三种情况下不同倾斜角对近场相位和远场强度的影响。数值结果表明,镜腔倾斜会使近场相位由均匀分布变成非均匀分布。从布导致远场光束质量变坏。     

倾斜固体潮及其组合信息与强震响应特征分析

采用格尔木和湟源倾斜数据计算倾斜固体潮潮汐因子及其组合信息,分析发现,倾斜M2波和O1波潮汐因子比值的不同离散程度对所处区域的应力水平和方向具有较好的指示意义。结合6级以上地震,进一步讨论了固体潮及其组合信息与强震之间的响应特征,得到：倾斜潮汐因子对6级以上地震响应较好,且主要为具有中短期预报意义的震前响应和同震响应。而在倾斜潮汐因子组合信息中,介质各向异性主要在震前4～5个月出现异常,剪切应变在震前1～7个月出现异常,面膨胀因子主要在震前1个月或震时显著增大,处于不同区域的倾斜潮汐因子组合信息对于强震的响应率并不相同。     

包含倾斜晶界的双晶ZnO的热输运行为

用嵌入位错线法和重合位置点阵法构建含有小角度和大角度倾斜角的双晶氧化锌纳米结构.用非平衡分子动力学方法模拟双晶氧化锌在不同倾斜角度下的晶界能、卡皮查热阻,并研究了样本长度和温度对卡皮查热阻和热导率的影响.模拟结果表明,晶界能在小角度区域随倾斜角线性增加,而在大角度区域达到稳定,与卡皮查热阻的变化趋势一致.热导率随样本长度的增加而增加,卡皮查热阻表现出相反的趋势.然而随着温度的增加,热导率和卡皮查热阻都减小.通过比较含5.45°和38.94°晶界样本的声子态密度,发现声子光学支对热传导的影响不大,主要由声子声学支贡献,大角度晶界对声子散射作用更强,声学支波峰向低频率移动.