普通物理教材中氦氖能级图的一些问题

现有的普通物理教材中，在有关激光章节中介绍氦氖激光器耐，关于氦氖能级图可谓五花八门，图1～4给出了几本教材中(包括激光的专门教材)的氦氖能级图．可以看到对氖能级标注的光谱学符号各不相同，一些教师反映备课时不知哪一个是正确的?     

Simultaneously compensating tunable CD and adaptive PMD using two different nonlinearly chirped fiber Bragg gratings

Experimental research of simultaneous tunable chromatic dispersion(CD)and adaptive polarization mode dispersion(PMD)compensations in optical fiber communication system was reported.Two different nonlinearly chirped fiber Bragg gratings fabricated through the equivalent chirp technology were adopted in the experiment.One of the gratings was used as CD compensator,with a tunable dispersion range from 300 to 600 ps/nm.The other made of photosensitive polarization maintaining fiber was used as a tunable delay line of PMD compensator,which provided a varying amount of differential group delay(DGD)from 40 to 110 ps.Our experiment was operated at 10-Gb/s non-return-to-zero(NRZ)system and the results showed that the eye pattern recovery is excellent after both PMD and CD are compensated.Especially,the power penalty at a bit error rate(BER)of 10-9 is about 1 dB.     

直接激光气化产生水溶剂化的氧化镁团簇

用飞行时间质谱仪探测了直接激光气化碱式碳酸镁样品产生的质谱，结果表明：氧化镁团簇与同时产生的水分子发生了原位溶剂化反应并产生了各种尺寸的溶剂化氧化团簇离子，这些团簇离子包括：（Ｍｇ（Ｈ２Ｏ）ｍ）＾＋（ｍ＝０，１，２，３），（Ｍｇ（ＭｇＯ）Ｈ２Ｏ）ｍ（ｍ＝１，２，３，４）（Ｈ（ＭｇＯ）（Ｈ２Ｏ）ｍ）＾＋（ｍ＝０，１，２，３，４，５，６），（Ｈ（ＭｇＯ）２（Ｈ２Ｏ）ｍ）＾＋（ｍ＝０，１，２，３，４，５     

利用波叠加观点讨论光波导模式的物理意义

不同于传统的光波民模式理论，本文从光波叠加的观战分析了光波导中形成光场模式的机制，给我场模式的物理定义，用普通物理方法计算了平面光波导中模式的场分布，并给出了特征方程以及一些波导参量的物理意义。     

孕妇分娩方案的模糊综合评判

本文应用模糊数学方法建立孕妇分娩方案的综合评判模型 .此模型应用于临床实践 ,获得了满意的效果     

三芯非线性光纤耦合器中的短脉冲光开关

利用变分法研究三芯非线性光纤耦合器中的短脉冲光开关,解析分析线性三耦合非线性Schr?dinger方程的结果与数值模拟符合得很好.并且得到在非线性光纤耦合器中孤子的耦合长度和开关阈值,与连续波情况和两芯光纤耦合器的结果不同. 关键词： 光纤耦合器 光开关 耦合长度 开关阈值     

Zero dispersion wavelength and dispersion slope control of hollow-core photonic bandgap fibres

This paper investigates the zero dispersion wavelength and dispersion slope control of hollow-core photonic bandgap fibres (PBGFs) by using a full-vector finite element method. By simulation we found that theoretically the zero dispersion wavelength can be tailored by respectively changing the rounded diameter of air holes, pitch, refractive index, normalized thickness of core rings, and hole diameter to pitch ratio. At the same time the tailoring of dispersion slope can also be realized by changing the rounded diameter of air holes or pitch or normalized thickness of core rings. To illustrate the reasonability of fibre designs, this paper also gives the variance of normalized interface field intensity which measures the scattering loss relatively versus wavelength for different designs. From the viewpoint of loss, varying the rounded diameter and the thickness of core ring could shift zero wavelength but it is difficult to get the required parameters within so tiny range in practical drawing of PBGFs, on the other hand, it is possible in practice to respectively alter the pitch and refractive index to shift zero wavelength. But varying hole diameter to pitch ratio is not worthwhile because they each induce large increase of loss and narrowness of transmission bandwidth. The zero dispersion wavelength can be engineered by respectively varying the rounded diameter of air holes, pitch, refractive index, and normalized thickness of core rings without incurring large loss penalties.     

40 Gb/s光时分复用系统中两级偏振模色散自适应补偿实验研究

偏振模色散效应严重制约着长距离高速光纤通信的发展,偏振模色散的自适应补偿成为光通信领域研究的焦点。利用两阶段偏振模色散补偿器,采用6个自由度的粒子群优化算法(PSO),通过在线监测搜索光纤链路信号的偏振度极值作为反馈控制信息,在40Gb／s归零码高速光纤传输链路中成功实现了ms量级的偏振模色散自适应补偿。补偿前后采用庞加莱球法测量光纤链路中偏振模色散量,测量结果表明在信号中心波长1560．5nm处,差分群时延补偿前后测量值分别为21ps和1．3ps,而二阶偏振模色散补偿前后测量值分别为266ps^2和43．5ps^2。补偿后实验链路中的一阶和二阶的偏振模色散同时得到不同程度的补偿,并且系统的总的功率代价在误码率为10^-9时小于1dB。     

提高RZ码偏振度椭球对偏振模色散响应范围的方法

提出了使用适当带宽的光带通滤波器和选择合适的脉冲宽度两种方法来增加RZ码光纤通信系统中偏振度椭球对偏振模色散的响应范围,模拟计算得到了40 Gb/s的 RZ码在不同脉冲宽度以及同一脉冲宽度下不同的滤波器带宽两种情况下偏振度椭球的短轴随偏振模色散的变化情况. 结果表明, 采用这二种方法可以明显地提高偏振度椭球的短轴对偏振模色散的响应范围. 另外, 数值模拟结果还表明对于40 Gb/s的系统滤波器带宽应大于50 Hz, 光源脉宽应在4 ps~10 ps较为合适. 通过实验证明了这二种方案是可行的.     

甲苯对水/AOT/醇反相微乳液体系电导行为的影响

采用电导法研究了以二(2-乙基己基)琥珀酸酯磺酸钠(AOT)为表面活性剂、庚醇和癸醇分别与甲苯的混合溶剂为油相的反相微乳液体系在有无添加剂氯化钠时的电导行为。 结果表明,甲苯对水/AOT/癸醇体系电导渗滤有明显的抑制作用,而对水/AOT/庚醇体系没有影响;添加氯化钠对水/AOT/庚醇（癸醇）/甲苯体系的电导率基本无影响。