基于新型耦合腔VCSOAs的交叉增益调制

提出利用无源耦合腔结构以拓展VCSOA的增益带宽,从而实现基于VCSOA的交叉增益调制波长转换新构想.结合载流子密度速率方程和传输矩阵方法,首次对该新型耦合腔结构VCSOA的波长转换特性进行了数值模拟,重点研究了泵浦光功率以及信号光功率对转换光消光比特性的影响.仿真获得了上下各4 nm的波长转换范围,该结果已大大高于普通单腔结构VCSOA的增益带宽.     

一种用于通信C波段的光轨节点无源集成芯片

光轨是一种新型光通信网络结构,具有交换粒度小、带宽利用率高等优点。本文提出一种应用于通信C波段的新型光轨节点无源集成芯片,支撑1 545 nm、1 550 nm和1 555 nm三个C波段波长的通信。该新型光轨节点无源集成芯片是一种基于SOI纳米波导材料的片上微器件系统,核心器件由基于微环谐振器的解复用器和基于马赫-泽德尔干涉仪的环加强型热光光开关构成。通过理论计算和软件仿真,分别分析了解复用器和光开关的光学和通信性能,结果显示微环解复用器3个波长信道的串扰分别为22.5 dB、16.9 dB和16.3 dB;光开关的消光比分别为16.6 dB、19.7 dB和21.5 dB;插入损耗分别为0.86 dB、0.85 dB和0.68 dB,功耗约为51 mW。     

自由空间的微闪耀光栅光开关

微光学元件在现代光学中具有重要的作用,通过制作8台阶的微闪耀光栅列阵,控制周期参数,利用其在空间的闪耀输出与级连,可以实现2×2、4×4以及8×8的光开关功能,光信号交换透明,无光电-电光转换过程。对微闪耀光栅输出信号的串扰分析表明,微闪耀光栅光开关可以有效的抑制串扰问题,在全光网络通信中具有一定的应用。     

基于分束器与双向型的光分插复用器分析研究

在分析了光纤光栅光分插复用器结构的基础上,设计了双向型和基于分束器与双向型2种新型的四波长光分插复用器结构。双向型光分插复用器结构与传统的光分插复用器相比可以处理双向网络信号,其特点是系统中相对较少地使用环形器,减少了系统损耗,输出光谱与原光谱更接近;基于分束器与双向型的光分插复用器与双向型相比增加了传输的路数。采用OptiSystem软件对两种结构进行仿真,仿真实验结果显示,双向型和基于分束器与双向型光分插复用器能很好地完成四波长同时上下载任务。     

光纤水听器时分复用阵列串扰分析

采用高相干窄带光源的光纤水听器时分复用(TDM)阵列中,信号光与其余通道的泄漏光之间不是简单的强度叠加,而是互相干涉。以此为基础,推导了8路TDM阵列中各通道光束相互作用的理论公式,得到了光开关的消光比是决定系统串扰的主要因素,最大串扰值约为消光比的一半的结论。信号解调采用相位载波解调(PGC),由于串扰频率分布广且远高于信号频率,提出了采样前先低通滤波的信号检测方案,该方案可滤除串扰高频成分,大大减小串扰频率混叠对PGC解调的影响。     

SAC-OCDMA系统中AWG的应用及串扰分析

概述了阵列波导光栅的特点及其在谱域幅度编码的光码分多址通信系统中的应用。基于地址码M序列,采用数值计算的方法,分析了阵列波导光栅的串扰对谱域幅度编码的光码分多址通信系统误码率性能的影响。结果表明,当阵列波导光栅的串扰较小时(Rc=-27dB),谱域幅度编码的光码分多址通信系统具有较好的性能;而当其串扰较大时(Rc=-20dB),谱域幅度编码的光码分多址系统的性能明显恶化,成为影响谱域幅度编码光码分多址通信系统性能的一个重要因素。     

光互联网中新型双向可调OXC的设计

本文提出一种新型双向可调2×2的OXC结构,采用可调光纤布喇格光栅和环行器构成。由2×2基本结构能方便地扩充到N×N的B-OXC。此结构具有插入损耗较小、结构简单、体积小、价格便宜等优点,在未来的全光网络中具有广泛的应用前景。     

光镊力谱系统双光束串扰因素研究

为了降低和消除光镊力谱系统中双光阱之间的干扰,进一步提高测试精度,本文对双光阱光镊系统中两光束间串扰的成因及其对力谱测量的影响展开了研究.研究发现,高倍物镜组与样品池构成的光学结构会引起光束偏振态的改变,是双光束串扰形成的主要因素;偏振分光棱镜自身的分光特性是串扰产生的另一因素;光阱捕获的微球,虽然改变了光束的形状和传播方向,但在光束串扰方面贡献很小.双光束的串扰信号叠加在探测的光强信号上,影响了光阱刚度和位移灵敏度的标定,最终导致力学测量的偏差.光镊系统中双光束的串扰量在同一次实验的一定时间内基本稳定.根据双光阱光镊系统的这一特点,本文提出了实时测量双光阱光镊系统两光阱独立存在时和同时存在时双光阱的刚度和位移灵敏度的方法,并经多次实验求平均后得到两种情况下双光阱的刚度和位移灵敏度的比值,在后续实验中,将该比值作为修正参数对实测的力谱曲线进行修正.结果表明,该方法有助于减小双光束串扰的影响,优化力谱测量结果,测试精度提高3.4!.     

2.5GHz非归零码光脉冲的波长变换实验

报道了采用国产器件进行了中心波长为１．５５μｍ，重复频率为２．５ＧＨｚ的非归零码光脉冲基于半导体放大器的交叉增益调制的波长变换实验，波长变换距离２．７ｎｍ。     

基于AWG实现OADM实验研究

设计了基于位相波导光栅（AWG）的复用和解复用双重功能的两种OADM网元实现方案,分析并实验研究了两种OADM网元的串扰特性。结果表明,采用一定结构设计的OADM网元可以较好地减小串扰影响。     

Power penalty for burst mode reception in the presence of interchannel crosstalk

A full theoretical analysis considering the impact of interchannel crosstalk arising from wavelength division multiplexing on DC coupled burst mode reception is provided and fundamental penalties are calculated for signal independent and signal dependent noise dominant regimes. The specific context is that of a wavelength division multiplexed passive optical network. The impact of different interchannel crosstalk ratios on the overall penalty, and the difference between this and the sum of the two individual penalties (burst mode and crosstalk), is investigated for different preambles. The difference between the combined penalty and the sum of individual penalties (i.e. the 'extra' penalty), when the preamble short and the crosstalk ratio poor, can be of similar significance to the separate penalties. The effect is potentially worse when signal dependent noise is dominant. Data within a packet experiencing a different level of crosstalk to that present during the packet`s threshold acquisition preamble, due to the packetized nature of the crosstalk, is also investigated.     

Dynamic O-band to C-band wideband wavelength converter for integrated VCSEL-based optical interconnects

ABSTRACT

Real-time wavelength conversion and traffic routing at key network nodes is a fundamental requirement for current optical interconnects. This work experimentally demonstrates a broadband wavelength conversion from O-band to C-band employing commercially available, power efficient VCSELs. A 1310?nm VCSEL is directly modulated with 8.5 Gbps data and transmitted over 22?km G. 652 fibre with a 0.53 dB penalty. The received data is used to run a 1550?nm VCSEL located at the network integration node, achieving the first reported wavelength conversion from O-to-C-band. VCSEL wavelength tuneability with changing bias current functionality is further exploited to route the converted wavelength over 400?GHz spectra range for integration into wavelength flexible networks. The newly converted wavelength is transmitted over 24.7?km of G. 655 fibre, incurring a maximum penalty of 1.86?dB. Results from this work proves an enabling development technology for wavelength converters for transparent contention resolution in current and future optical Interconnects.     

Self-seeded reflective semiconductor optical amplifier based optical transmitter for up-stream WDM-PON link

A novel up-stream transmitter for wavelength division multiplexed-passive optical network (WDM-PON) using a self-seeded reflective semiconductor optical amplifier (RSOA) was proposed. The RSOA was self-seeded by an amplified spontaneous emission itself using a fibre Bragg grating without an additional optical source. The side mode suppression ratio of self-seeded output signal and the extinction ratio were ~28 and 8.1 dB, respectively. Required power for 10^-9 BER at 622 Mb/s was about -28 dBm and the power penalty after 20 km transmission was <2 dB for 30 nm range of wavelength     

波长路由在并行计算机光互连中的应用

提出了一种波长路由并行光互连技术，其路由直接在源端用目标地址选择波长来建立，各波长有独立传输路径并采用光通道复用，路由变换节点为全光结构，光信号在变换节点处无转发延迟。此技术可应用于并行计算机互连网络和分布式高性能计算机群的互连网络。     

基于最小化波长需求的波长路由光网的优化设计

讨论了波长路由光网的资源优化设计问题,提出了一种新的整数线性规划（ILP）公式,用于解决波长通道（WP）和虚波长通道（VWP）的路由选择和波长分配问题,它的优化目标是最小的网络需求,以中国高速信息示范网（CAINONET）为例,分析了波长通道（WP）和虚波长通道（VWP）路由方案之间在波长需求方面的差别,同时还研究了网络波长重用度的问题。     

多波长光网络的动态路由等效算法

针对多波长光网络的特点，提出了一种动态路由和波长分配的等效算法。采用波长图、增加虚拟源节点和目的节点等技术，把多波长网络转化为等效的单波长网络，避免了求解路由和波长分配两个复杂子问题，简化了算法的程序设计。利用最短径算法进行路由和波长分配可以求得问题的最优解，从而有效地降低了网络阻塞率。仿真结果表明：与FAR-2D算法相比，在4和8波长的全波长转换网络中，采用等效算法阻塞率最大降幅分别达到0．02、0．025。     

Comparative analysis of wavelength-multiplexed photonic-sensor networks using fused biconical WDMS

Three networks based on fused biconical wavelength division multiplexers (WDMs) and fiber Bragg gratings (FBGs) are theoretically and experimentally demonstrated for photonic-intensity-sensor multiplexing. The aim of replacing standard couplers for WDMs in the power division process is to reduce power losses and improve the robustness of the systems to FBG wavelength shifts. The different network topologies are analyzed both in terms of power budget and crosstalk noise, considering the multiplexing of two fiber-taper displacement sensors. The configuration with one detector for each sensor and the corresponding FBG at the detection end is proven to be the best topology in terms of crosstalk, doubling the peak-isolation value of the WDMs employed and yielding a 37.4 dB optical signal-to-noise ratio for a two-sensor network. Regarding power losses, the optimum configuration locates the FBGs at the sensor heads, thus improving power budget and avoiding additional couplers at the detectors. Both topologies are expanded to multiplex four sensors, with crosstalk identified as the critical factor in these networks. With this limiting parameter, the first configuration has been determined as the most suitable for multiplexing a high number of sensors.     

光纤作为量子信道的性能

本文研究光纤作为量子信道在密波分复用时模式间非线性干扰造成的信道噪声的性质 ,和光纤量子信道在该噪声下的经典容量 .用位移算符方法计算量子噪声的累加 ,同时建立了有衰减和噪声时的信道的量子模型 .本文论证如果干扰是各其他模式独立而均等的贡献的叠加 ,信道噪声是热辐射噪声类型的 ,并求出了在给定参数的情况下的经典容量     

Free-space optical crossbar network integrated in a single block of LiNbO3 crystal

A free-space optical crossbar network integrated in a single block of LiNbO(3) crystal is proposed, which consists of stages of 2×2 switches making use of the electro-optic effect of crystal and in-between routing devices for permutation based on double refraction and internal double reflection on interfaces. Two basic configurations are suggested. A control algorithm for the crossbar network is discussed, which may control a nonblocking interconnection between any input and output. The integrated crossbar network is low energy loss, nonblocking, easy to assemble, and insensitive to environment. A 3×3 crossbar network is designed and the experiment is demonstrated.