用激光外差法探测固体表面超声位移

论述了应用激光外差和锁相环解调原理探测固体表面超声位移的原理、方法、并利用激光外差干涉仪对固体表面的超声位移进行了探测，得到了很好的结果。     

2×1.244Gb／s光时分复用系统的研究

使用光纤作延迟器，利用高温熔融拉伸法微调延迟时间，完成了２×１．２４４Ｇｂ／ｓ全光时分复用系统，满足了同步传输模式的要求。     

First scanning Fabry-Perot interferometer developed in China

A scanning Fabry-Perot interferometer （SFPI） was first developed and deployed at the Langfang near Space Environment Field Scientific Observation Station （39.38°N, 116.65°E） of the National Space Science Center, CAS. The instrument is designed to measure the mesospheric and ther- mospheric wind velocities using the atomic oxygen 557.7-nm and 630.0-nm emissions. Data from February 28 to March 3 and February 28 to March 15 in 2011 were chosen for case study and mean value study, respectively. The errors of the meridional and zonal winds are 6.5 and 7.5 m/s at 557.7-nm and at 630.0-nm, they are 7.1 and 6.6 m/s, respectively. During the whole experiment, the instrument has performed in good condition and provided high-quality data. The mean neutral wind data were consistent with that predicted by HWM07. Good agreement has been found in between the SFPI and a neighbor Meridian Project Fabry-Perot interferometer （MP FPI）, with a corresponding coefficient （re） larger than 80 %. In general, the scanning FPI meets the design goal, and it is a useful ground-based instrument for measuring mesospheric and thermospheric winds at middle latitudes and is able to provide high-quality data for future scientific studies.     

迈克耳孙干涉仪改进方法对比研究

用GSZF-4型迈克耳孙干涉仪测量He-Ne的激光波长时,系统误差主要来源于迈克耳孙干涉仪传动装置的传动比不为一恒定值.通过对该问题作进一步分析,并提出新的改进方法,使传动装王的传动比为一恒定值.从实验结果对比分析发现,对于现有仪器,该方法简单易行,有利于减小系统误羔,提高实验精度.     

基于光纤Fabry-Perot的电流传感器

利用光纤抗电磁干扰、绝缘性好, 体积小等特性,提出一种新型的光纤电流传感器. 该传感器将悬臂梁结构和光纤Fabry-Perot相结合,基于材料力学理论和电磁感应原理,利用Fabry-Perot干涉仪原理来实现对电流的测量. 在解调方式上采用了相位解调法,分析了该传感器的工作原理及光纤F-P的测量原理,建立了光纤F-P腔的数学模型,推导出电流检测理论公式,并进行了相关实验,证明该电流传感器具有绝缘性好、结构简单、灵敏度高等优点.     

FDA对测向时差组合定位的欺骗研究

针对雷达电子战中,敌方无源探测雷达通过接收干扰机信号实现测向定位,威胁我方干扰机安全的问题,提出一种基于频率分集阵列(FDA)的测向时差组合定位欺骗技术。首先在建立FDA阵列模型的基础上,通过欧拉公式得到采用非线性频控函数的FDA阵列因子及相位方向图;之后推导了FDA阵列作用于干涉仪测得的信号到达角β;之后,以虚拟干扰机位置与真实位置的欧氏距离D为评价指标,分析欺骗效果。仿真结果表明,阵列载频位于L、S波段的欺骗效果优于X波段。在一定参数范围内,D值随着阵列阵元总数、阵列载频的增加而增大。远场条件下,采用正弦及对数频控函数的FDA阵列在消除方向图耦合的同时,其定位欺骗的D值取值在6～10km之间。     

基于最大后验概率的单星多目标无源定位算法

为提高单星无源定位精度和速度,同时满足小型化和低功耗的要求,提出了基于最大后验概率和旋转长基线干涉仪的无源定位算法。核心思想是利用最大后验概率原理解决多辐射源信号去交织难题;利用旋转干涉仪天线基线和目标辐射源来波方向瞬时变化减小测向定位模糊,从而实现了利用单个旋转长基线干涉仪系统对多辐射源目标快速高精度定位。仿真表明,该算法可行性强,定位精度高、速度快,具有很高的应用价值。     

LiTaO3强度调制器在脉冲调制中的稳定性研究

介绍工作在1．053μm波长下Mach-Zehender(MZ)LiTaO3光强度调制器的工作原理．对它在脉冲调制时的稳定性进行了研究,讨论了直流电压漂移造成的工作不稳定性的问题．根据系统的特点,首次采用补偿电压和光开关相结合的工作方式,在没有信号的周期中输入补偿电压,释放积累在调制器里的电荷,并在补偿周期关闭光路,防止光泄露影响下一级系统,在两级串连的情况下,得到了-45dB的消光比。     

不同DDF构成的MZI的光脉冲压缩特性比较

比较了3种不同色散递减类型光纤构成的马赫-曾德尔干涉仪（MZI）的先脉冲压缩特性．结果表明：考虑高阶效应时,各种色散渐减光纤构成的MZI的脉冲压缩比例较大,脉座能量也大,对数渐减光纤构成的MZI压缩脉冲质量最好;不考虑高阶效应时,也是对数渐减光纤构成的MZI的压缩脉冲质量最好．     

Squeezing bandwidth controllable twin beam light and phase sensitive nonlinear interferometer based on atomic ensembles

We review our recent experimental progress in quantum technology employing amplification effect of four-wave mixing in a rubidium vapor. We have produced an intensity difference squeezed light source at frequencies as low as 1.5 kHz which is so far the lowest frequency at which squeezing has been observed in an atomic system. Moreover, we find that the bandwidth of our squeezed light source can be controlled with light intensity pumping. Using our non-classical light source, we have further developed a nonlinear Mach-Zehnder (MZ) interferometer, for which the maximum fringe intensity depends quadratically on the intensity of the phase-sensing field at the high-gain regime, leading to much better sensitivity than a linear MZ interferometer in which the beam splitters have the same phase-sensing intensity. The quantum technologies developed by our group could have great potential in areas such as precision measurement and quantum information.