交叉增益型波长转换器的实验研究

全光波长转换器是全光网络中的关键光电子器件.基于半导体光放大器的交叉增益型波长转换器具有结构简单容易实现、转换效率高、波长转换范围宽以及转换速率高的特点.文中在自行研制半导体光放大器的基础上,对交叉增益型波长转换器进行了实验研究.讨论了实现波长转换的基本原理,描述了实验系统结构,实现了速率为140Mbit/s的1315nm和1301nm之间的波长转换.研究了波长转换器泵浦光功率、探测光功率以及放大器注入电流转换效率、消光比和噪声特性的影响,研究结果与文献中报道的相同.研究表明,不同因素对不同指标的影响是相互制约的,要全面提高波长转换器的性能,必须折衷考虑各方面的因素.研究结果对半导体光放大器结构参数的优化和波长转换工作条件的优化有一定的指导作用.     

全光型波长转换器及其在通信系统的应用

综述了基于半导体光放大器的全光型波长转换器在未来高速大容量通信系统中的应用,比较了不同工作方式的优缺点,介绍了转换器的最新研究进展。     

适用于PolSK调制的FWM型全光波长转换器

文章提出了一种利用半导体光放大器(SOA)中的四波混频(FWM)效应、适用于偏振移位键控(PolSK)调制的全光波长转换器方案.注入的辅助光可以缩短SOA增益恢复时间,增大饱和功率,提高波长转换效率.通过数值模拟从理论上实现了这种全光波长转换器,研究了输入泵浦光、信号光和辅助光功率对全光波长转换器输出特性的影响.     

基于半导体光放大器全光波长转换器的研究进展

详细讨论并分析了三种以半导体光放大器为基础的全光波长转换器的优缺点，并介绍了一些改善性能的最新方案，最后作了一些展望。     

半导体光放大器四波混频的波长转换器理论分析

从理论上探讨了半导体光放大器四波混频机制,并由耦合波方程,推导了波长转换效率的表达式。进一步分析了如何提高波长转换效率的方法,既可从放大器本身入手,也可通过优化其工作条件入手,为改善波长转换器的性能提供了理论依据。     

应变量子阱光放大器NDFWM波长转换和滤波

报告了一种新型的波长转换滤波器，它产生于拉伸/压缩应变量子阱（T/CSQW）光放大器中的非简并四波混频（NDFWM）。提出T/CSQW转换滤波器的结构，并由器件的耦合模式实现了波长的转换滤波。讨论了T/CSQW光放大器的特征参数对输出效率，输出带宽及频移的影响。在0.01量级，该器件可用作具有高转换效率及窄带的滤波器和波长转换器，其频率转换的范围取决于半导体介质的增益带宽，可达到5000GHZ。     

半导体量子点集成有机发光二极管的光光转换器进展

介绍的光光转换器是新型红外光-可见光转换器件,红外光产生的光生载流子直接注入有机发光二极管产生可见光。以半导体红外探测与有机发光器件单片集成的光光转换器,直接实现了红外光到可见光的集成转换,在红外凝视技术中有极大的应用潜力。综述了无机红外探测与有机发光的光-光转换器的研究进展。     

交叉增益调制型全光波长转换器频响特性的小信号分析

对基于半导体光放大器交叉增益调制型全光波长转换器的频响特性作了理论分析,并获得了反映注入光参数对波长转换频响特性影响的解析表达式．数值结果表明,波长转换的频率响应带宽依赖于光放大器驱动电流、注入光波导的光功率以及转换波长间隔     

基于半导体光放大器四波混频波长转换的理论研究

本文对基于半导体光放大器四波混频效应的波长转换作了理论分析,得到了波开转换效率与半导体光放大器特性参数以及注入泵浦光功率等关系的解析表达式,通过数学模拟表明,波长转换效率受到泵浦光功率的饱和功率等参数的影响。本文结果将为波长转换器的合理设计提供了理论依据。     

基于单端SOA波长转换器的消光比特性分析

对一种基于单端半导体光放大器(SOA)的交叉增益调制型(XGM)全光波长转换器结构建立了动态理论模型,以这个模型为基础分析了抽运光功率、探测光功率、剩余反射率、转换波长转换间隔、注入电流对转换后探测光的输出消光比的影响.结果表明,利用单端SOA实现波长转换比普通SOA实现波长转换将获得更好的输出消光比特性.     

Multicast with a new switching structure in optical networks

The emergence of new services demands for a multicast function in optical networks. At the same time, wavelength converters are introduced to increase the efficiency of wavelength usage. It is because of the high cost and complex architecture of optical multicast and wavelength conversion technology, that a new switch structure is introduced, in which optical splitters and wavelength converters are shared per-node. In order to accommodate this architecture, a multicast routing and wavelength assignment algorithm in a splitter–converter-sharing optical network and a changing link weight policy to balance network traffic are proposed. By extending RSVP-TE (Resource ReSerVation Protocol-Traffic Engineering) and OSPF-TE (Open Shortest Path First-Traffic Engineering), an optical multicast mechanism is provided, and message type, signaling flow, and finite state machine model are given. Simulations of NSFNET show that, when the number of splitters and converters are 50% and 12.5% of the full equipment respectively, the performance is close to the ideal case. Using a changing link weight policy can improve performance greatly, when there are enough splitters and converters.     

Efficiency and noise performance of wavelength converters based onFWM in semiconductor optical amplifiers

All optical frequency converters are key devices for new-conception optical networks. A theoretical model is presented to evaluate performances of frequencies converters based on highly nondegenerate four-wave mixing (FWM) in semiconductor amplifiers. Conversion efficiency and noise performances are evaluated in generic saturation conditions and compared with experimental results     

Analyzing the polarization dependence in optical spot-sizeconverter by using a semivectorial finite-element beam propagationmethod

This paper describes a semivectorial wide-angle finite-element beam propagation method (FE-BPM) that uses the Pade approximation and that can allow efficient and accurate analyzes of the polarization dependence in arbitrary step-index optical waveguide devices. It also reports the use of this method to analyze the polarization dependence of coupling loss between a semiconductor tapered-waveguide spot-size converter and a single-mode optical fiber. It is shown that semiconductor spot-size converters having cores with a small cross-section provide low-loss and polarization-insensitive coupling to flat-end fibers. A low-loss (far less than 1 dB) and completely polarization-insensitive spot-size converter can be made using a lightly n-doped InP substrate for the tapered waveguide. These spot-size converters are consequently potentially useful for making polarization-insensitive semiconductor optical devices such as optical amplifier gate switches     

All-optical wavelength conversion using a pulse reformatting optical filter

We introduce a general concept for the design of all-optical wavelength converters with pulse reformatting functionality. The novel wavelength converters are based on a single semiconductor optical amplifier followed by an optical filter. A microelectromechanical system-based realization is shown and simultaneous 40 Gb/s wavelength conversion, switching and signal format conversion is demonstrated. The new pulse reformatting optical filter device outperforms current schemes with respect to input-power requirements, input-power dynamic range and signal quality.     

Optical Noninvasive Diagnostic of Semiconductor Devices by Using Laser Beam Probe

The optical noninvasive diagnostic of characteristic of silicon semiconductor de-vices by using a InGaAsP/InP semiconductor laser as an optical probe is reported.The princi-ple of experimental method is based on the dependence of the optical refractive index on the carrier charge density in the active region of devices and detection of variation of refractive index by two laser beam interferometric techniques.     

All-optical wavelength conversion by semiconductor opticalamplifiers

Following a brief introduction to the applications for wavelength conversion and the different available conversion techniques, the paper gives an in depth analysis of cross gain and cross phase wavelength conversion in semiconductor optical amplifiers. The influence of saturation filtering on the bandwidth of the converters is explained and conditions for conversion at 20 Gb/s or more are identified. The cross gain modulation scheme shows extinction ratio degradation for conversion to longer wavelengths. This can be overcome using cross phase modulation in semiconductor optical amplifiers that are integrated into interferometric structures. The first results for monolithic integrated interferometric wavelength converters are reviewed, and the quality of the converted signals is demonstrated by transmission of 10 Gb/s converted signals over 60 km of nondispersion shifted single mode fiber     

外部光反馈对强耦合外腔半导体激光器特性影响的理论分析

本文从理论上分析了外部光反馈对强耦合外腔半导体激光器特性的影响，对相干外部光反馈和非相干外部光反馈两种情形的分析结果均表明强耦合外腔半导体激光器可将半导体激光器所能容忍的临界光反馈强度提高大约２０ｄＢ以上，同时得出了长外腔和强耦合有利于提高外腔半导体激光器抗反馈能力的结论。     

All-optical wavelength conversion with large wavelength hopping by utilizing multistage cascaded SOA-based wavelength converters

A novel broadband wavelength converter by multistage cascaded semiconductor optical amplifier (SOA)-based wavelength converters is proposed. We have demonstrated, for the first time, broadband wavelength conversion in the wavelength range of 1320-1610 nm by using three-stage cascaded SOA-based wavelength converters with each different gain band.     

Optical spot-size converters for low-loss coupling between fibersand optoelectronic semiconductor devices

Structures of spot size converters that allow low loss and easy coupling between an optical semiconductor device and a fiber are proposed and designed theoretically. These spot-size converters have a tapered small core for expanding the mode field. They also have a double cladding region which consists of an n⁺-doped InP substrate as the outer cladding and a p-doped or nondoped InP layer as the inner cladding with a ridge structure. This double cladding utilizes the plasma effect of a carrier which makes the refractive index of highly doped n-InP lower than that of p-doped or nondoped InP. The double-cladding structure can tightly confine an expanded mode field in the inner cladding, and results in low radiation loss at the tapered waveguide, in addition, this structure reforms the mode field shape into a Gaussian-like shape and achieves a low loss coupling of less than 1 dB with a large misalignment tolerance for fiber coupling. These spot-size converters are easily fabricated and applicable to all types of optical semiconductor devices     

2.5GHz光孤子传输

利用半导体光孤子源和掺铒光纤放大器成功地实现了２．５ＧＨｚ光孤子２１ｋｍ传输，并利用简化的半导体光孤子传输系统理论模型对实验系统进行了数值模拟计算，计算结果与实验结果基本一致。