亚微米AZO光栅及其漫透射分布特性

探讨亚微米掺铝氧化锌(AZO)光栅的漫透射光谱特性。在AZO薄膜上涂布光刻胶,用325nm激光双光束干涉曝光得到掩模图案。将其置于质量分数为0.5%的稀盐酸溶液中湿法刻蚀,制备出周期(780～1280nm)和高度(60～300nm)能独立调控的AZO一维光栅。正入射双向透射分布函数(BTDF)测试结果表明,400～900nm波段内平均镜面透射率随光栅周期增大而降低,与紫外-可见分光光度计测得的结果吻合;同时,周期越大被衍射到30°～80°范围内的漫透射比重和漫透射峰值均越大,而峰位角越小。根据光栅方程对实验结果给出了合理的解释。     

DMD光栅的衍射特性及其在可调谐激光中的应用

相比较于液晶空间光调制器,数字微镜晶片(DMD)具有开关速度快、显示精度高、偏振不相关、衍射效率高和宽带调制等优势。研究利用DMD的衍射效应作为波长选择器,将其应用于可调谐光纤激光器中,理论推导这种二维DMD光栅的衍射效率与入射光角度,像素间距等物理量之间的定量关系,重点讨论了两种不同像素间距的0.7″和0.55″DMD在单像素因子和多像素干涉共同作用下的衍射级数和强度分布。研究结果表明:0.7″DMD在光强不显著为零且满足实验约束条件下,允许出现4个干涉极大值,但由于极大值位置均远离闪耀条件,因此光强相对较弱。0.55″DMD仅出现1个干涉极大值,且接近闪耀条件,因此光强和效率均明显高于0.7″DMD的情况。由此可见,在可调谐光纤激光器中,利用0.55″DMD光栅作为波长选择器更有利于减小衍射损耗,提高系统稳定性。     

超声波声速测量方法的探讨

介绍一种测量空气中超声波声速的新方法--改变频率干涉法（也叫改变频率驻波法）.并对实验数据、测量精度进行了分析.     

干涉分波器上光程差的突变分析

用菲涅耳公式分析干涉分波器上发生的光程突变，比较各种类型干涉分波器产生光程突变的共同点和差异，这一点有利于对薄膜干涉中额外程差的选取。     

Interference in the Quantum Ising Model

Using the measure of interference defined in this paper, we investigate the quantum phase transition of one-dimensional Ising chains. We find that thermal fluctuations affect the interference more strongly at the critical point. We also show that the derivative of the interference with respect to the coupling parameter, A, can be depressed by the thermal fluctuation. Finally, we find that this suppression is due to multi-particle excitations.     

泡沫-水两用幕厚度与光衰减效果的关系

理论分析与实验研究了水幕系统施放泡沫-水两用干扰幕产生的泡沫幕/水幕施放厚度与光衰减效果的关系。实验对空中和模拟甲板表面施放不同气流量比例的4～32层离散液滴状水幕和泡沫幕,测量其对平行光的衰减。实验结果表明:对于不同泡沫-水两用幕施放位置和气流量比例,随着施放厚度的增加,光衰减效果均明显提高,透射照度的衰减最高可达95.8%（空中）与98.4%（甲板表面）;透射照度衰减的速率随施放层数的增加而逐渐减小。     

基于外差干涉的微振动测量技术研究

针对外差干涉的微振动测量存在稳定性低、严重受环境噪声影响等缺点,提出了对光路的改进方案。根据差分原理将其改为双光路,消除环境噪声的干扰;通过偏振分光棱镜（PBS）将椭圆偏振光变为线偏光,提高干涉信号幅值;改进频移装置(AOM),抑制频率漂移;增加光阑,滤除杂散光,提高系统信噪比。通过探测5 kHz压电陶瓷振动信号,以及2.5 MHz高频激光超声信号进行实验验证,结果表明:信号稳定且无纹波,系统分辨率为2.3 nm,信噪比提高16.7倍。两路干涉信号幅值分别为552 mV和736 mV,较传统外差干涉信号幅值提高近10倍,有利于纳米量级微振动信号的检测。     

Measurement-Based Interference in Quantum Computation

The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent with the visibility in qubit systems. By taking cluster states as examples, we show in the one-way quantum computation that the gate fidelity is proportional to the interference of the measured qubit and is inversely proportional to the interference of all register qubits. We also find that the interference increases with the number of the computing steps. So we conjecture that the interference may be the source of the speedup of the one-way quantum computation.     

Semi-classical theory and experimental research for polarization flipping in a single frequency laser with feedback effect

In this paper, we propose a semi-classical theory to successfully explain the polarization flipping in a single frequency laser. An experimental setup is built to verify this theory. The observed experimental phenomena are consistent with the theoretical analysis. We perform phase retardation measurements of birefringent components using this experimental system. The results show that the measurement repeatability is 0.12° and the measurement accuracy is 0.22 °.     

植醇对牧草中脂肪酸测定的干扰及其消除

通过对牧草脂肪酸的测定,分析气相色谱法直接碱催化甲酯化、碱皂化三氟化硼催化甲酯化2种前处理方法中植醇的干扰情况,优化碱皂化三氟化硼催化的试验条件。实验结果表明,在2种前处理方法中,植醇对牧草脂肪酸的测定均产生干扰,其中直接碱催化甲酯化法干扰较重。80℃是碱皂化三氟化硼催化甲酯化处理牧草的最优水浴温度,能完全去除植醇,且80℃时,脂肪酸的甲酯化效率最高。在添加量为100、500 mg/kg 2种水平中,5种脂肪酸甲酯的平均回收率在87.5%~94.1%之间,相对标准偏差(RSD)在2.0%~5.1%之间。改进的方法能消除植醇的干扰,其准确度和精密度能满足牧草脂肪酸测定要求。