All-optical wavelength conversion based on nonlinear polarization rotation (NPR) in SOA and AWG filtering

An all-optical wavelength converter, based on nonlinear polarization rotation (NPR) in semiconductor optical amplifier (SOA) and array waveguide grating (AWG) filtering, is experimentally demonstrated. The wavelength converter can provide excellent operation including extinction ratio and Q factor. The simultaneous two wavelength conversion outputs are successfully obtained at 20 Gb/s.     

Half baudrate electrical clock based demultiplexing scheme for OTDM-DQPSK signal using SOA and optical filter

A demultiplexing scheme based on semiconductor optical amplifier(SOA)and optical filter for optical time division multiplexing differential quadrature phase shift keying(OTDM-DQPSK)system is proposed and investigated experimentally.With only a common half baudrate electrical clock modulated 33%duty cycle return-to-zero(RZ-33)optical clock signal as pump,this scheme is cost-effective,energy-efficient,and integration-potential.A proof-of-concept experiment is carried out for the demultiplexing of a 2×40-GBd OTDM-DQPSK signal.Error-free performance is demonstrated,and the average power penalty for both channels is about 3 dB.     

基于Circle混沌映射的ISSA-ELM神经网络室内可见光定位方法

针对传统室内可见光定位精度较低、基于神经网络的室内可见光定位收敛速度慢且泛化能力弱等问题,提出一种结合基于Circle混沌映射的优化麻雀搜索算法-极限学习机（ISSA-ELM）神经网络和接收信号强度指示（RSSI）的室内可见光定位方法,在考虑天花板、墙壁和地板反射作用的情况下,将每个参考点处的RSSI和光电探测器的真实位置坐标作为训练集数据,对优化后的ISSA-ELM神经网络模型进行训练,建立室内可见光定位预测模型,并利用测试集对定位模型进行测试。仿真结果表明,优化后的ISSA-ELM神经网络的训练时间为0.0454 s,平均定位时间为3.5 ms,在5 m×5 m×3 m的室内环境,对位于0、0.5、1.0、1.5 m高度参考点的平均定位误差分别为1.01、1.14、1.36、3.87 cm,相比极限学习机（ELM）神经网络的定位精度分别提高了20.47%、19.72%、37.91%、42.32%。因此,所提的室内可见光定位方法具有定位速度快、定位精度高、系统性能稳定等优点。     

Towards 640 Gbit/s wavelength conversion based on nonlinear polarization rotation in a semiconductor optical amplifier

Taking into account ultra-fast carrier dynamics, this paper models 640 Gbit/s wavelength conversion scheme based on nonlinear polarization rotation （NPR） in a single semiconductor optical amplifier （SOA） and investigates the performance of this kind of wavelength conversion scheme in detail. In this model, two carrier temperature equations are introduced to substitute two energy density equations, which reduce the complexity of calculation in comparison with the previous model. The temporary gain and phase shift dynamics induced by ultra-short optical pulses are numerically simulated and the simulated results are qualitatively in good agreement with reported experimental results. Simulated results show that non-inverted and inverted 640 Gbit/s wavelength conversions based on NPR are achieved with clear open eye diagrams. To further investigate the performance of the non-inverted wavelength conversion scheme, the dependence of output extinction ratio （ER） on some key parameters used in simulation is illustrated. Furthermore, simulated analyses show that high performance non-inverted wavelength conversion based on NPR can be achieved by using a red-shifted filtering scheme.     

新型高分子手性固定相的制备

酒石酸N,N′-二烯丙基酰胺与异氰酸酯反应得到对应的手性衍生物(3a~3c)。3在丙烯酰化硅胶表面发生自由基聚合反应,得到用于高效液相色谱柱的新型高分子手性固定相。3及其手性固定相的结构经1HNMR,IR和元素分析表征。     

基于半导体光放大器交叉偏振调制效应实现正、反相波长变换

利用琼斯矩阵，对基于半导体光放大器中的交叉偏振调制效应实现全光波长变换进行了理论分析.结果表明，利用这种机制可以实现同相与反相波长变换.在实验上同时实现了10Gb/s归零信号的正相与反相波长变换，输出消光比分别达到了6.9 dB和8.1 dB.