Andreev-Fano Effect in a Hybrid Normal-Metal/Superconductor Interferometer

We report on a new type of Fano effect, named as Andreev-Fano effect, in a hybrid normal-metal/supeeconductor (N/S) interferometer embedded with a quantum dot. Compared with the conventional Fano effect, AndreevFano effect has some new features related to the characteristics of Andreev reflection. In the Iinear response regime, the line shape is the square of the conventional Fano shape, while in the nonlinear transport, a sharp resonant structure is superposed on an expanded interference pattern, which is qualitatively different from the conventional Fano effect. The phase dependence of the hybrid N/S interferometer is also distinguished from those of all-N or all-S interferometers.     

过氧聚钨酸薄膜上光栅的制备

用过氧聚钨酸（PPTA）水溶液，通过离心涂膜法在显微镜载玻片上制备了具有光滑表面且厚度为100nm的PPTA薄膜，利用PPTA薄膜在紫外光照下可研制光栅以及其它光学元件的薄膜材料，具有很高的利用价值。     

Implementation of a Nonzero-order Joint Transform Correlator Using Interferometric Technique

The implementation of a nonzero-order joint transform correlator using the double port Mach-Zehnder interferometric technique is proposed and demonstrated. This approach provides on-line processing for directly removing the zero-order components of a joint power spectrum in one step and performs the nonzero-order optical correlation. Experimental results are presented and discussed.     

An ASE Reduction Filter Using Cascaded Optical Fiber Grating Couplers in EDFA Repeater

A new configuration for an ASE reduction filter in EDFA repeaters for WDM optical transmission systems using optical fiber grating couplers (FGCs) was proposed and first demonstrated. The filtering characteristics of the proposed filter for amplified single wavelength signal and 2-channel WDM signals using EDFA were identified. It was found that the filter was effective to improve SNR in optical domain by reducing ASE noise. The required FGC characteristics for the filter were theoretically predicted under the condition that the total filter loss did not exceed 3 dB. More than 70% of drop efficiency was required in each FGC for the application of the proposed filter to an 8-channel WDM system using EDFA repeaters.     

Analysis of a Young–Michelson tandem interferometer

In a Young–Michelson tandem interferometer a Michelson interferometer is illuminated through a pair of Young slits. The pattern produced by this set-up is analyzed theoretically. The consequences of small misalignments and uncompensated arms in the Michelson interferometer are studied. The effects of the spatial and temporal partial coherence of the source are also explored. Experimental results using a laser source are shown to be in good agreement with the predicted theoretical calculations.     

基于悬臂梁调谐技术的光纤光栅无源振动监测

采用匹配光纤光栅设计了一种结构简单的振动信号无源监测装置.该装置利用悬臂梁调谐技术能够将微小振动信号转化为光电探测器可探测的光强信号,利用示波器实现实时监测.实验中对振幅为3mm的简谐振动信号进行了监测,测量结果与振动频率一致,可测量7～20Hz的振动,信噪比不低于14.9dB.监测频率受限是因为悬臂梁的性质,如采用金属材料或者采用齿轮组对转子进行减速,该装置可探测更高的频率.     

用迈克耳逊干涉仪测量气体折射率的误差的研究

研究在用迈克尔逊干涉仪测量气体折射率时存在的系统和方法误差，提出了误差修正方法。     

F-H实验仪与光栅光谱仪连用观测253.7nm谱线

通过F-H实验仪和光栅光谱仪的连用，可实时观测汞原子从6s6s1So态激发到6s6sSP1态，退激时，辐射出能量为4．9eV的光量子，其波长为253．7nm．     

Focused ion beam Moiré method

A focused ion beam (FIB) Moiré method is proposed to measure the in-plane deformation of object in a micrometer scale. The FIB Moiré is generated by the interference between a prepared specimen grating and FIB raster scan lines. The principle of the FIB Moiré is described. The sensitivity and accuracy of deformation measurement are discussed in detail. Several specimen gratings with 0.14 and 0.20 μm spacing are used to generate FIB Moiré patterns. The FIB Moiré method is successfully used to measure the residual deformation in a micro-electro-mechanical system structure after removing the SiO₂ sacrificial layer with a 5000 lines/mm grating. The results demonstrate the feasibility of this method.     

高斯光束计算平板波导自由传输区远场分布及其修正

对近轴近似条件下求解亥姆霍兹方程得到的高斯光束显式传播公式做了分析，同时，基于基尔霍夫衍射理论，在菲涅耳近似的条件下给出了相应的高斯光束在远场的传播公式，在此基础上，对近轴近似条件做出了定量分析，给出了这个近似条件引入的误差，提出了一种计算高斯光束远场分布的修正方法，并采用有限差分-光束传播方法(FD-BPM)来检验各种方法的准确性。把这种修正方法应用到平面光集成波导器件，如阵列波导光栅(AWG)、蚀刻衍射光栅(EDG)等器件的设计和模拟中，可以大大降低工作的复杂性，同时可以得到精确的结果。