离子交换过程中的加速效应研究

本文系统地回顾了作者在大孔离子交换树脂交换过程中的加速效应研究结果。肯定并总结了加速效应的存在及规律;探讨了加速效应的起因,用吸附双电层的概念作了理论解释。最后介绍了这一效应在离子交换分离技术中的应用。     

Widely tunable all-optical wavelength converter based on four-wave mixing using two orthogonally polarized pumps

The principle of broad-band orthogonal-pump (BOP) four-wave mixing in semiconductor optical amplifiers is analyzed in theory. The conversion efficiency reduces rapidly as the detuning of wavelength between the signal and pump increase which can be solved by introducing a BOP method. The constant conversion efficiency and signal-to-noise ratio are obtained over a large wavelength detuning range. The wavelength conversion efficiency with variation smaller than 3.88 dB over 52-nm range has been experimentally demonstrated by using BOP, with the 10-GHz output of distributed feedback/electro-absorption modulator as signal. Conventional single-pump scheme is also performed for comparison and the experimental results fit well with the theory.     

8字形主被动锁模掺Er3+光纤激光器

在理论上分析了利用非线性光学环形镜作为等效可饱和吸收体压缩脉冲进行锁模的物理机制。利用8字形主被动混合锁模的结构在调制频率2．498749GHz下，在1．543μm处获得了12ps的锁模脉冲输出，对应谱宽0．22nm，时间脉宽积0．33。在抽运功率50mW情况下，输出脉冲平均功率3．715mW。在调制频率2．499344GHz、2．499114GHz和2．498999GHz时分别并获得了2～4阶幅度较为均衡的有理数谐波锁模脉冲序列。     

利用交叉增益调制实现光时分复用波分复用波长变换

采用半导体光放大器的交叉增益调制效应 ,通过全光方法 ,实现了 1.2Gbit/s光时分复用信号转换成2× 6 2 2Mbit/s波分复用信号的解复用。它同样具有波分复用信号到光时分复用信号波长变换的功能。     

Wavelength and duration tunable soliton generation from a regeneratively mode-locked fiber laser

A 10-GHz soliton source with pulse duration between 4-8 ps and wavelength continuously tunable from 1530 to 1563 nm is presented. Using regeneratively mode-locking technology, the harmonically modelocked fiber ring laser could work without pulse dropout at room temperature when no cavity length or polarization maintaining mechanism is available. Applying only one 980-nm laser diode pump, the average output power reaches more than 4 mW.     

加速离子的流洗色谱分离研究(Ⅰ)——Cu(Ⅱ)-氯合离子的加速作用

前报曾报导了Mn(Ⅱ)的加速效应。此后又肯定了这一效应的普遍性及应用于流洗色谱的可能性。本文发现了4N HCl中的CuCl_x~(x-2)-是一种有效的加速离子,可以改善U(Ⅵ)的色谱床效,以此实现了U(Ⅵ)、Ti(Ⅳ)和Fe(Ⅲ)的色谱分离。 按文献[2],以～t作图,对理想的色谱图,可得到对称的一对直线,相交于S处,在络合色谱中,前沿属快扩散组份,偏离平衡的程度Q小,容易得到直线,     

Tunable multi-wavelength fiber ring laser based on a Hi-Bi fiber loop mirror

A novel tunable multi-wavelength fiber ring laser based on semiconductor optical amplifier (SOA) is proposed by using a high-birefringence (Hi-Bi) fiber loop mirror (FLM) as wavelength filter. With this configuration, the wavelength spacing of this laser can be varied by using the different lengths of Hi-Bi fiber. 8 wavelengths spacing on 450 GHz are experimentally obtained with more than 25-dB signal-to-noise ratio (SNR) for each channel using 1.28-m Hi-Bi fiber in Hi-Bi FLM. The output power variation between different channels is measured to be less than 5.9 dB. The linewidth of each channel is compressed from 0.347 to 0.186 nm by 1.5-m unpumped erbium-doped fiber (EDF). Meanwhile, 17 wavelengths spacing on ITU-gird (100 GHz) are also obtained with 5.9-m Hi-Bi fiber in Hi-Bi FLM. All these channels can be tuned together over 0.4 nm.     

超连续谱光纤的优化设计

比较了三种不同色散光纤用于超连续过程时的频谱展宽特性，在此基础上对产生宽带、平坦超连续谱超连续谱的普通色散位移光纤的参量进行模拟设计，并提出优化设计应遵循的原则。     

金属离子交换过程中的扩散问题——滞留时间、成因及其规律

以强酸型大孔树脂为固定相,用浅床法系统研究了UO_2~(2+),U(IV)等高价金属离子在吸附和解吸过程中的扩散问题.确认了扩散滞留时间的存在;并提出相界面吸附双电层模型,解释了它的成因及有关规律.     

Tbit/s超大容量光纤通信系统的研究进展

Tbit/s超大容量光纤传输系统促进了光纤通信技术的发展。综述了采用波分复用技术(WDM)、光时分复用技术(OTDM)和WDM/OTDM混合方式的Tbit/s超大容量光传输系统的研究现状、技术实现方式及研究的最新进展。对各种传输系统的优缺点进行了评价,对Tbit/s光纤通信系统的前景作了展望。