OTDM add-drop multiplexer based on time-frequency signal processing

A time-division add-drop multiplexer capable of high-extinction-ratio operation is presented both theoretically and experimentally. The approach used is based on time-to-frequency domain conversion of optical signals and relies upon the switching of linearly chirped optical pulses. By converting a 40-Gb/s optical time-division multiplexing (OTDM) signal to 4 /spl times/ 10-Gb/s wavelength-division multiplexing (WDM) channels and using fiber Bragg gratings for frequency-domain add-drop multiplexing, a timeslot suppression ratio in excess of 30 dB and error-free operation for the dropped, through, and added channels were achieved. A further stage of WDM-to-TDM signal conversion was used to map the resulting signal back into the time domain. Moreover, it is shown that it is straightforward to simultaneously operate on multiple channels by simply cascading gratings to make more complex filtering functions without the requirement for any further synchronization of the tributary channels.     

双向波长上下路光分插复用器

通过对科技文献的归纳总结和分析比较,介绍了四种实现双向波长上下路的光分插复用器结构和工作原理,它们是：（1）基于FBG和多口光环形器;（2）基于波导光栅路由器和FBG;（3）基于阵列波导光栅（AWG）;（4）基于解复用器／复用器对和光开关的OADM结构。     

空间级联可调谐光滤波器方式实现光分插复用器

提出一种采用空间级联可调谐光滤波器方式实现的OADM.该器件不但具有集成度高、体积小、插入损耗低、信道间插入损耗差异小的特点,而且能够在控制电路的作用下灵活选择上下路波长及其数量,为构建灵活、高性能的WDM网络提供了选择.     

Integrated laser and add-drop optical multiplexer for narrowband wavelength division multiplexing

The fabrication and characterisation of a monolithically integrated narrowband add-drop multiplexer and DBR laser are reported. Multiplexer bandwidth of 2-3.5 nm have been measured with a Bragg extinction ratio >23 dB.<>     

All-fiber add-drop wavelength-division multiplexer based onintermodal coupling

We demonstrate a novel all-fiber add-drop multiplexer by using a tilted Bragg grating written on a two-mode fiber and a mode-selective coupler. The device can be made potentially with low loss and low cost, useful for add-drop of a small number of channels in wavelength-division-multiplexing (WDM) communication systems     

光网络中的动态可重构的光分插复用技术

动态可重构的光分插复用器(ROADM)在光通信网络与传感网络中有重要的应用,而且是对目前正在使用的非重构的光网络升级的核心技术之一.超大规模、高可靠性的传感器网络对可重构的OADM需求尤其迫切.结合本课题组承担的863项目的研究成果,对该技术进行介绍.     

基于马赫曾德尔干涉结构的硅基波分复用器

文章提出了一种基于马赫曾德尔干涉结构的硅基 波分复用器。该器件可通过集成的电 光移相器实现对器件中各通道传输谱的调节,来补偿外界温度变换和工艺误差造成的波长漂 移。测试结果表明,热光移相器的效率为3mW/π,可以实现4个通道的波分复用,通道间隔 为3.3 nm,隔离度大于30 dB。     

可调谐双芯光子晶体光纤波分复用器设计

数值分析了双芯光子晶体光纤的耦合特性,设计出0.85/1.55μm、0.98/1.55μm和1.3/1.55μm基于通信波段的波分复用器件,其光纤长度分别为542μm、996μm和932μm.在双芯光子晶体光纤的基础上,光纤长度固定不变时,通过调节中心空气孔材料折射率,材料折射率分别为1.281、1.343和1.348...     

All-optical regeneration based on highly nonlinear photonic crystal fiber

An all-optical regeneration based on selfphase modulation in a highly nonlinear photonic crystal fiber is proposed. The dispersion and nonlinearity properties of a series of photonic crystal fibers are analyzed, and the results show that the nonlinearity coefficient is closely related to the structure of the fiber.In this paper, the nonlinearity coefficient is increased by reducing the effective mode area, and a highly nonlinear photonic crystal fiber with a large air-filling fraction is used as nonlinearity medium in optical regeneration. The numerical results show that good optical regeneration results can be obtained by using a relatively short fiber length due to the high nonlinearity of the fiber. The input peak power launched into the photonic crystal fiber and the parameters of the filter have much influence on optical regeneration. To achieve good optical regeneration, those parameters need to meet certain requirements.Furthermore, the transfer characteristic of the regenerator is also discussed. By adjusting the input peak power and filter parameters, the regenerator can deal with input pulses of different pulse widths.     

城域网中可重构型分插复用器的新发展

城域光网络的升级对可重构型分插复用器(ROADM)技术的发展产生了巨大的推动作用.分析和归纳了当前ROADM产品的特点和应用,指出了ROADM发展的新动向和市场前景.     

Super compact optical add-drop multiplexer for FTTH applications based on low-loss polymer waveguide materials

Four- and eight-channel arrayed-waveguide grating (AWG) and fixed optical add-drop multiplexer (OADM) devices with channel spacing of 1200 and 600 GHz have been fabricated using super-high refractive index contrast (/spl Delta/n=0.020) triazine containing polymers. Accordingly, the size of the four-channel AWG was only 10/spl times/3 mm and the insertion loss was 3 dB.     

Performance analysis of variable optical delay circuit using highly nonlinear fiber parametric wavelength converters

The performance of a variable optical delay circuit that employs a fiber loop with highly nonlinear fiber parametric wavelength converters is discussed using both experiments and simulations. In our optical delay circuit, the delay time is determined from the number of circulations, which is controlled by the initially selected wavelength of the optical signal. We discuss the factors that limit the number of circulations described in our previous paper, derive the parameters that provide good performance levels, and confirm the performance by simulation. The simulated results indicate that 100 wavelength conversions can be achieved, namely, 100 different delay times can be given to optical packets.     

Arrayed waveguide lens wavelength add-drop in silica

We present experimental results of an integrated 16-channel, 100-GHz-channel-spacing wavelength add-drop in silica. It consists of two interleave-chirped waveguide grating routers connected by an array of waveguides containing thermooptic phase shifters. The fully packaged device has 6.6-7.6-dB fiber-to-fiber insertion loss and a switching extinction ratio >27 dB (>33 dB for a single polarization) when used as an add-drop, It is compact, allowing for at least four such devices per 5-in-diameter wafer     

10-GHz return-to-zero pulse source tunable in wavelength with asingle- or multiwavelength output based on four-wave mixing in a newlydeveloped highly nonlinear fiber

In this letter, a novel scheme for a wavelength-tunable pulse source (WTPS) is proposed and characterized. It is based on four-wave mixing (FWM) in a newly developed highly nonlinear fiber between a return-to-zero (RZ) pulsed signal at a fixed wavelength and a continuous wave probe tunable in wavelength. The corresponding FWM product acts as the WTPS, and is implemented in a 10-Gb/s, 160-km transmission experiment and in a 40-Gb/s multiplexing/demultiplexing experiment. The scheme can be expanded to a multiwavelength WTPS, which is demonstrated for two wavelengths. The introduced penalty using the WTPS compared to the original RZ pulses is negligible     

基于非线性色散光纤的全光波长变换

理论推导了基于光纤中四波混频效应的全光波长变换效率公式,利用OptiSystem成功模拟出了基于非线性色散光纤的全光波长变换.通过调整抽运光与信号光的频率差、抽运光功率、光纤衰减系数、光纤的有效面积等参量,获得了变换效率为15.4dB的变换光.     

Wavelength conversion technique based on self phase modulation in highly nonlinear microstructure fiber

A wavelength converter based on the self phase modulation(SPM) effect in highly nonlinear microstructure fibers(MFs) is proposed.The core diameter and the pitch of the fiber are 2.05 μm and 5.0 μm,respectively,and the diameter of the airholes in the fiber cladding is 4.50 μm.The calculating nonlinear coefficient is 112.2 W-1 km-1 and it is 11 times higher than that of a conventional dispersion-shift fiber and 56 times higher than that of a conventional single-mode fiber.The length of the fiber i...     

一种基于多模干涉波导的超低尺寸波分复用器

波分复用/解复用器作为数据传输的核心器件,广泛应用于片上光互联网络中,其中最重要的指标就是器件的尺寸,插入损耗和串扰大小,为解决传统硅基阵列波导光栅尺寸较大,阵列波导光栅光强不均的问题,我们提出了一种基于绝缘体上硅(SOI)的环形反射器辅助多模干涉波导的四通道波分复用器,可以实现不同通道的波长分离。其核心尺寸仅为10μm×34μm,最小相邻通道串扰为-1442dB。     

High-power widely tunable 40-GHz pulse source for 160-gb/s OTDM systems based on nonlinear fiber effects

We numerically analyze and experimentally demonstrate an innovative and simple 40-GHz source for 160-Gb/s optical time-division multiplexing. The source is based on nonlinear evolution of a sine-modulated lightwave in a Raman-pumped fiber. Proper nonlinear propagation produces the simultaneous soliton generation and compression. High-power soliton-like pulses are obtained with <1-ps pulsewidth. The source can be tuned over 20 nm and it has more than 100-mW average output power.     

Low-insertion-loss, tunable wavelength multiplexer on lithium niobate

Integrated-optical dual-channel multi/demultiplexers with a wavelength periodic transmission characteristic are fabricated on X-cut LiNbO3. The devices are designed for the wavelength range ? = 1300-1600nm. Channel separations as low as 30nm, far-end crosstalk attenuation up to 40dB and an insertion loss of fibre-coupled devices below 3dB are achieved. The transmission characteristic can be tuned electro-optically at a rate of 2.5 nm/V.