导致光聚物全息存储布喇格偏移因素的研究

研究了光聚物高密度全息存储材料在全息记录过程中曝光量、曝光时间、厚度收缩比例、折射率调制度及记录角度等因素对布喇格偏移的影响规律,结果表明:曝光量一定时,布喇格偏移与曝光时间的关系不大,当曝光量不一定时布喇格偏移随曝光时间增加缓慢增加最后达到饱和;而布喇格偏移随厚度收缩比例和折射率调制度的增加以接近正比例的关系增加;记录光栅的倾斜度越大则布喇格偏移也越大.这些结论对光聚物高密度全息存储研究具有重要的意义.     

A New 1×K Tunable Multi-wavelength Router and its Features

Tunable wavelength routers (TWRs) for multiple wavelength selection are key devices in dynamic wavelength-routing wavelength division multiplexing (WDM) networks. In this paper, by cascading conventional 2×2 TWRs, a new 1×K TWR is proposed for large-scale dynamic wavelength-routing WDM networks. When the cascading numbers are smaller, the 1×K TWR can be directly applied to networking WDM networks. When the cascading numbers are larger, the 1×K TWR can be carried out by the integrating method and be extensively used to networking various multi-wavelength optical networks by the way of “EDFA+TWR”. Though the cascading method proposed is based on the acousto-optic TWRs, it can be also applied to cascading other kinds of TWRs.     

百焦耳级XeCl准分子激光实验研究

介绍了西北核技术研究所利用“闪光Ⅱ号”强流相对论电子束加速器作泵浦源研制的百焦耳级XeCl准分子激光器的主要性能和实验结果。     

短波瑞利衰落信道FH／MFSK编码系统的性能

基于ＳｔｕｂｅｒＧ．Ｌ．的系统模型，研究带反馈链路的选择式频率分集与编码ＦＨ／ＭＦＳＫ系统在具有加性白高斯噪声（ＡＷＧＮ）的瑞利衰落信道中的编码性能，给出了采用ＲＳ码、双－ｋ码、重发码时，编码前与编码后系统的码符差错概率与比特能量噪声比的关系曲线．研究结果表明：无编码时，单纯增加分集重数Ｌ对系统性能的改善并不是十分明显的，只有同时采用分集与编码技术，才能有效地改善系统的性能．     

Ultrasonic resonance regulated near-field scanning optical microscope and laser induced near-field optical-force interaction

We have developed a novel sample-tip regulation for a near-field optical microscope: an ultrasonic resonance regulation method. The regulation range is from 0 to 50 nm. It shows not only stability, simplicity in construction, but also versatility in vacuum, magnetic field, and low temperature environments. The main advantage of this technique is that it is a non-optical detecting scheme, which is very important for near-field spectroscopy. Such construction can also be used as a force microscope to study the topography of insulating samples. The laser light induced force interaction in the near-field range has been observed for the first time, showing that aided by laser radiation, the shear force between sample and tip can be changed depending on the type of sample. This can be interpreted as the light induced optical tip-sample interaction of light pressure effect. The van der Waals dispersion energy and the optical binding energy induced by laser beam between dielectric tip and samples play important role. The effect confirms a theoretical prediction. This new technique and phenomenon will add new aspects to near-field optics.     

飞秒脉冲激光对YAG晶体的辐照作用的研究

采用波长为800nm，脉冲宽度为120fs的飞秒激光对提拉法和温梯法生长的YAG晶体进行辐照。并对辐照后的样品进行吸收光谱及电子顺磁共振谱(EPR)的检测。结果表明，提拉法的晶体在经过辐照后，255nm吸收峰减弱，同时在370nm处产生新的宽峰吸收，其产生原因是由于样品内部分Fe^3 转化成Fe^2 ，并有少量F^ 心生成。对比两种不同方法生长的晶体，温梯法生长的YAG晶体的抗激光辐照能力略优于提拉法生长的晶体。     

用余震数据研究震区应力状态的一种计算机处理方法

使用全面搜索和优化处理相结合的方法,由一组余震的P波初动解资料可以推断出余震区的构造应力的主轴方向,应力主值的相对大小(1),并同时确定了余震的两个P波节面中的断层面。对1976年唐山地震相1966年邢台地震的余震资料的计算处理,都给出了余震区的主压应力为水平东西向,主张应力为近水平南北向的结果。因此可以认为,本方法对于用地震资料研究应力场是一个有用的工具。