一种新型的空气扰动探测方法

基于光折变材料的二波耦合特性提出了一种新型的空气扰动探测方法。空气中的微扰导致入射到光折变材料中两束光的光程差发生改变，干涉条纹随之发生变化。由于光折变体相位栅建立时间比较长，体相位栅不能及时跟随干涉条纹发生变化，导致干涉条纹与体相位栅间的相移将随空气扰动信息的变化而变化。相移角的改变将导致瞬态能量转移，输出两束光的能量在瞬态能量转移作用下将实现对空气扰动信息的光调制，并且这种调制过程是一种差分调制方式。在接收端采用电差分检测方法便可解调出空气扰动信息。这种利用光折变体相位栅的差分探测方法在未来的探测领域将有广泛的应用前景。     

Temperature effect on dissipative holographicscreening-photovoltaic solitons in a biased dissipative system

In a biased dissipative photovoltaic-photorefractive system, this paper investigates the temperature effect on the evolution and the self-deflection of the dissipative holographic screening-photovoltaic （DHSP） solitons. The results reveal that, the evolution and the self-deflection of the bright and dark DHSP solitons are influenced by the system temperature. At a given temperature, for a stable DHSP soliton originally formed in the dissipative system, it attempts to evolve into another DHSP soliton when the temperature change is appropriately small, whereas it will become unstable or break down if the temperature departure is large enough. Moreover, the self-deflection degree of the solitary beam centre increases as temperature rises in some range, while it is decided by the system parameters and is slight under small-signal condition. The system temperature can be adjusted to change the formation and the self-deflection of the solitary beam in order to gain certain optical ends. In a word, the system temperature plays a role for the DHSP solitons in the dissipative system.     

Evolution and stability of spatial solitons in a photorefractive two-wave mixing system

The dynamical evolution and stability of bright dissipative holographic solitons in biased photorefractive materials in which the self-trapping beam obtains a gain from the pump beam via two-wave mixing has been investigated numerically. Results show that these solitons are stable relative to small perturbations. Adjusting some system parameters, such as the bias field and the angle between beams, can easily control the generation of such solitons. Potential applications in optical switches or repeaters are discussed.     

用RSP—Ⅰ型全息干版做光学全息演示实验

采用新型红敏光致聚合物全息干版拍摄全息图,在日光灯下操作,实验过程观察得清楚;位相型全息图的处理方法简单;重现的全息像效果明显:具有高亮度、高清晰度、极强的立体感,强烈的艺术效果.     

光折变空间光孤子的顶侧面观测法

基于CCD图像采集技术与计算机软件处理技术，提出了空间光孤子的顶侧面观测法.此方法能够非常直观地显示出光孤子在晶体内部传输时，在水平及垂直方向上不同位置的轮廓图.用这种方法观测到了KNSBN晶体中的二维光伏明孤子，观测结果与理论模拟结果相一致.     

基于光折变双光束耦合的刚性全息明孤子的温度依赖特性研究

研究了基于双光束耦合的光折变耗散系统中全息明孤子的温度演化特性.数值计算结果表明，晶体温度与刚性全息孤子的稳定性密切相关.在一定温度下，全息孤子能在晶体中传播足够远的距离；当晶体温度漂移不大时，入射孤子能演化成稳定的全息孤子继续传播；而当晶体温度变化足够大时，孤子波强度随传播距离增加或减小，入射孤子不能以稳定的全息孤子态传播.讨论了将刚性全息孤子的温度特性应用于光学衰减、中继器件的可能性. 关键词： 空间光孤子 光折变非线性光学 耗散系统 全息聚焦     

A polarization stabilizer up to 12.6 krad/s with an additional function of stable state of polarization transformation

This paper reports on an experiment about a novel method of polarization stabilization. The polarization stabilizer proposed here has an additional function of polarization transformation from any state of polarization into any others. The particle swarm optimization is introduced as a control algorithm in the process of either searching or endless tracking. The tracking speed of the stabilizer is obtained up to 12.6~krad/s by using hardware we have in the laboratory, which means that we can achieve a higher speed practical polarization stabilizer if we have faster hardware.     

闭路光伏暗空间孤子的自偏转特性研究

通过考虑扩散效应的影响,采用数值方法,研究了一维稳态闭路光伏暗空间孤子的自偏转特性。结果表明,在扩散项的影响下,光伏暗空间孤子光束的中心沿一个抛物线轨迹在光折变晶体光轴方向上产生偏转;孤子中心偏转距离随光伏场以及入射孤子波强度的增加而单调增加。光伏暗空间孤子与明孤子的自偏转规律有明显不同。     

红敏光致聚合物全息干板的特点及其使用方法

RSP—Ⅰ型红敏光致聚合物是一种新型全息记录介质,它完全由国产化学试剂配制而成。它对氦氖激光λ=632.8nm的红光敏感。感光灵敏度为1mJ/cm~2,衍射效率>80%。分辨率>4000cy/mm。在室温环境下可保存半年以上。可在日光灯下拍摄全息图。所摄反射型体积全息图图像清晰、明亮,可与重铬酸盐明胶版媲美。     

An experiment of PMD compensation in 40-Gb/s PSBT transmission system

An adaptive polarization mode dispersion （PMD） compensation experiment is reported in a 40-Gb/s phase shaped binary transmission （PSBT） communication system, with the use of a new digital signal processor （DSP）-based optical PMD compensator. PMD tolerance is found to be enhanced by 8 ps after PMD compensation with 1-dB optical signal-to-noise ratio （OSNR） penalty. Under the condition of fast change of states of polarization up to 85 rad/s in the fiber link, the performance of our PMD compensator undergoes the bit error ratio （BER） test for as long as 10 h.