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。     

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。     

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。     

离子交换树脂传质特性之评价问题

为全面评价离子交换树脂的传质动力学特性,提出了测量扩散常数、扩散活化能和滞留时间的必要性和方法,并通过三种大孔磺酸型树脂中UO_2~(2_(1/4))+的传质对比研究作了解说     

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4NHCl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。     

大孔阳离子交换树脂内UO2^2^+被加速传质的起因及规律

研究了大孔阳离子树脂内碱土、3d过渡元素和稀土等离子对UO2^2^+加速传质的起因及规律。发现,树脂内磺酸根及与之结合的金属离子周围水合数的降低是导致UO2^2^+被加速传质的起因。因此,同价离子对UO2^2^+的加速效应一般随其离子半径的加而增大,但加速离子起因不同的电子结构具有特强的键合力时,会使其加速效应发生异常。     

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.     

谐波锁模掺铒光纤激光器的稳定性研究

对谐波锁模掺铒光纤激光器的稳定性进行了实验研究.采用再生锁模技术控制腔长变化对稳定性的影响,提出了在腔内利用缠绕光纤法替代保偏光纤以获取偏振稳定机制的方案,并进行了相关实验.利用自相位调制＋频谱滤波抑制超模噪音,实验中当抽运功率在50 mW以上时就足可以抑制超模噪音.实验结果表明:采用以上三种措施能够较好地解决影响谐波锁模光纤激光器稳定的温漂、偏振起伏和超模噪音问题,从而大大提高了谐波锁模光纤激光器的稳定性.