基于超连续谱的光阈值器的实验研究

光阈值器件能够抑制光码分多址(OCDMA)系统中多址干扰(MAI)噪声,增加用户数量。基于超连续谱(SC)的光阈值器件,对偏振态不敏感,而且结构简单,易于实现。为克服放大器放大倍数和高非线性光纤(HNLF)长度对SC阈值实验研究的限制,本文提出通过改变输入脉冲占空比来改变峰值功率的方法。在通信波长为1 550nm的OCDMA系统中,基于SC的阈值时,最佳阈值脉冲峰值功率为6.195W,所需带通滤波器中心波长为1 558nm,带宽为5nm。     

可编程控制波长调谐的环形掺铒光纤激光器

提出了一种新型的可调谐光纤激光器,器件采用介质薄膜干涉滤波器进行波长可编程调谐,调谐范围超过38 nm(1 526.5～1 564.6 nm),中心波长可精确调谐到C波段指定的ITU-T波长栅格的标准中心波长处,3 dB带宽小于0.08 nm,25 dB带宽小于0.22 nm,波长稳定性优于0.01 nm,边模抑制比大于60 dB,最大输出光功率35.6 mW,功率稳定性优于±0.02 dB,阈值泵浦功率和斜率效率分别为5.8 mW和36.6%.     

波长可调谐掺铒光纤激光器的特性研究

利用我们已经研制成功的不依赖于偏振的声光可调谐滤波器(AOTF)作为调谐元件,提出一种新型的线性腔的波长可调谐掺铒光纤激光器.这种激光器的结构简单,调谐范围可达60nm,而且调谐速度快,调谐非常方便. 从三能级速率方程出发,结合线性腔的激光器理论及调谐器件AOTF的滤波原理,从理论上对这种激光器的输出特性进行了分析,得到输出功率、抽运阈值功率和斜率效率随波长变化的解析式.计算了满足位相匹配条件的中心波长分别为1533 nm,1553 nm及1570 nm时激光器输出功率随波长的变化.当抽运功率为40 mW时,输出功率约为6.7 mW,抽运阈值功率为4.3 mW,3 dB线宽约0.7 nm,而且不同中心波长的激光输出稳定.通过调节抽运功率、降低损耗以及改善滤波器性能等方式,可以将3 dB线宽减少至0.4 nm.(OD5)     

热光可调谐Si基聚合物列阵波导光栅

报道了用五氟苯乙烯共聚甲基丙烯酸环氧丙酯(PFS-co-GMA)的聚合物材料制备的33×33信道热光(TO)可调谐的阵列波导光栅(AWG)。给出了器件的制作工艺流程和测试结果。测得器件的波长间隔为0.81nm,3dB带宽为0.35nm,串扰约为-20dB,中心输出信道和边缘输出信道的插入损耗分别为10.4dB和11.9dB,TO可调谐值为-0.12nm/K,在温度为10~65℃时的器件工作中心波长为1545.21~1551.81nm,调谐范围为6.6nm。     

SOI基微环谐振可调谐滤波器

采用电子束光刻和ICP刻蚀等工艺制作出基于SOI纳米线波导微环谐振滤波器。滤波器微环半径为5μm左右,波导截面尺寸为(350nm～500nm)220nm不等。测试结果表明,波导宽度为450nm时器件性能最为理想,其自由频谱宽度为16.8nm,1.55μm波长附近的消光比为22.1dB。通过对微环滤波器进行热光调制,在21.4℃～60℃温度范围内实现了4.8nm波长范围的可调谐滤波特性,热光调谐效率达到0.12nm /℃。同时,研究了基于单环和双环的多通道上下载滤波器,实验结果表明多通道滤波器的信号传输存在串扰,主要是不同信道之间的串扰,尤其在信号上载时,会在相邻信道产生较大串扰。     

基于新型两级集成光学声光可调谐滤波器的环形腔掺铒光纤激光器

设计了一种以新型两级集成光学声光可调谐滤波器(IAOTF)为调谐元件的环形腔单偏振输出可调谐掺铒光纤激光器,它具有结构简单、调谐方便、调谐速度快和调谐范围大的优点。在对该集成光学声光可调谐滤波器滤波特性进行分析的基础上,在忽略放大的自发辐射(ASE)和激发态吸收情况下,对该激光器的特性参量如线宽、输出功率、斜率效率、阈值抽运功率等进行了分析。当抽运功率为100 mW,射频为175 MHz时,激光器输出中心波长为1550 nm,最大输出功率约6.34 mW,斜率效率为7.19%,半峰全宽(FWHM)为0.1 nm。当声波频率每改变0.1 MHz时,激光器输出中心波长改变约为0.88 nm,由于集成光学声光可调谐滤波器的滤波范围很大(当声波频率变化20 MHz时,滤波范围为180 nm),所以激光器的调谐范围仅取决于掺铒光纤的增益带宽。     

射频反馈法实现声光可调谐滤波器稳频输出

在集成声光可调谐滤波器(AOTF)工作时,由于环境温度变化以及自身声表面波吸收使器件的温度发生变化,导致滤出波的中心波长发生漂移。在理论分析的基础上,对声光可调谐滤波器的温度特性进行了实验研究,并在此基础上提出一种新的解决方案:用动态控制射频信号来实现声光可调谐滤波器的稳频输出,并用该方案实现了中心波长的漂移控制在0.08 nm以内,满足了波分复用(WDM)通信系统的应用要求。     

射频反馈法实现声光可调谐滤波器

在集成声光可调谐滤波器(AOTF)工作时,由于环境温度变化以及自身声表面波吸收使器件的温度发生变化,导致滤出波的中心波长发生漂移.在理论分析的基础上,对声光可调谐滤波器的温度特性进行了实验研究,并在此基础上提出一种新的解决方案:用动态控制射频信号来实现声光可调谐滤波器的稳频输出,并用该方案实现了中心波长的漂移控制在0.08 nm以内,满足了波分复用(WDM)通信系统的应用要求.     

利用AOTF的可调谐光纤激光器的特性研究

提出了一种新型的可调谐光纤激光器 ,其谐振腔是由声光可调谐波长滤波器 (AOTF)和掺铒光纤构成的Fabry Perot腔。该激光器具有调谐方便 ,调谐速度快和调谐范围大的优点。在忽略激发态吸收和放大的自发辐射情况下 ,对该激光器的线宽和调谐特性以及阈值抽运功率和斜率效率进行了理论计算。在中心工作波长 15 5 0nm处 ,得到输出峰值的半极大值线宽 (FWHM)约为 0 2 6nm ,并且在 15 5 0nm附近 ,声波频率每改变 1MHz所调谐的峰值波长间隔约为 8 95nm。理论上 ,调谐范围只受掺铒光纤增益和滤波器带宽的限制。计算结果表明 ,该激光器的阈值抽运功率和斜率效率分别为 0 795mW和 15 15 %。     

基于DMD滤波器的波长间隔可调谐的双波长单纵模光纤环形激光器（英文）

提出一种稳定的波长间隔可调谐的双波长单纵模环形光纤激光器.在复合环形谐振腔中,采用由数字微镜装置(DMD)滤波器和两个不同长度的次级环形谐振腔组成的多重滤波的方式来选择激光器的工作模式.其中,DMD滤波器可以从掺铒光纤的自发增益谱中任意选择两个波长并将它们耦合进光路中;次级环形谐振腔作为模式滤波器,可以保证激光器输出单纵模激射;利用非线性光子晶体光纤(HN-PCF)的四波混频(FWM)效应,使激光器输出均衡平稳的双波长激射.在室温条件下,不用移动实验装置中的任何器件,通过将位置不同的光栅映射在DMD滤波器上来实现双波长间隔可调谐,调谐范围为0.165 nm到1.08 nm,调谐步长为0.055 nm.     

一种可调谐的宽带喇曼波长转换器

为了提高宽带波长转换技术的响应速度，采用高非线性光子晶体光纤，设计了一种受激喇曼散射的可调谐全光宽带波长转换器。基于光纤中喇曼效应，对光子晶体光纤喇曼增益谱采取高斯曲线进行拟合，建立了喇曼波长转换器的理论模型，并进行了仿真分析，讨论了光纤长度对转换效率的影响。结果表明，在符合通信系统的条件下，实现了100nm转换带宽，波段为1487nm~1587nm，Q因子随探测光波长变化与喇曼增益谱走势相同，其波长转换质量最优处在喇曼增益系数最大处。该研究对未来光网络的波长转换器波长分配以及光纤长度的配置研究具有参考意义。     

A novel integrated optics wavelength filter in InGaAsP-InP

An InGaAsP-InP integrated optics wavelength selective device is proposed and demonstrated. It utilizes coupling between epitaxial layers with different refractive indices and thicknesses. The device is suitable for integration to form, e.g., a monolithic receiver for wavelength division multiplexed optical communication systems. Design considerations are given. The filter bandwidth and center wavelength can be freely chosen, and bandwidths as narrow as 1.5 nm at 1.3 or 1.55 μm center wavelength are shown feasible. Electrical tuning is possible. Experimental filters show that devices can he fabricated with performance in good agreement with theory, The 22-nm -3-dB bandwidth at 1.12-μm center wavelength presently demonstrated is limited by the measurement system.     

一种基于压电控制FBG的改进型快速调谐OADM

在光纤通信系统中,OADM是实现波分复用技术的重要器件之一,其信道间隔、带宽及选频速度等参数决定了系统的性能。OADM的核心器件是光滤波器,为了提高其带宽及速度,提出了一种基于压电控制FBG的快速调谐OADM,设计了基于PZT快速控制应变场实现波长选通的调谐结构。系统调制电压范围为0～160 V,实现了对1 548. 325～1 553. 248 nm范围内的扫频。通过Matlab仿真分析获得了FBG有效长度、调制深度与反射光峰值反射率和反射带宽的函数关系,并依据此确定了系统参数。实验利用PZT对FBG进行波长选通控制,结果显示,加载曲线与卸载曲线基本相符、线性度好,能够实现快速窄带带通控制。并对1 548. 325 nm信号光的上、下载及直通进行了测试,结果符合设计要求。该新型OADM具有控制速度快、线性度高等优点,在光纤通信中具有一定的应用价值。     

非线性光栅自调制光限幅器件研究

研制出一种三角槽型透明高分子聚合物光栅与该聚合物平板间填充有机非线性光学液体的夹层结构器件，具有非线性自调制光限幅功能。实验测得该器件对较弱的532nm波长的YAG倍频激光透过率大于60％。对较强激光透过率小于2％～3％。理论预期在激光波长400-700nm都有光限幅特性。且愈靠近532nm波长。激光限幅功能愈强。首次从实验上验证了该非线性光栅具有自适应宽带光限幅的功能。它不仅可以实现可调谐光限幅。且对所设计的激光波长，达到能量低于人眼安全阈值的高效激光防护成为可能。     

2 μm noise-like mode-locked fiber laser based on nonlinear optical loop mirror

We report a Tm-doped noise-like mode-locked (NLML) pulsed fiber laser with a compact linear cavity which consists of dual nonlinear optical loop mirrors (NOLMs). The design of dual-NOLM shows both exceptional compactness in construction and distinct flexibility. In this laser, mode-locking can be realized through the nonlinear optical loop mirror technique. Stable noise-like mode-locked pulses with spectral bandwidth of 29.18 nm and pulse energy of 46 nJ are generated at a central wavelength of 1 999.7 nm. Our results indicate that such a simple and inexpensive structure can pave the way for the development of generating supercontinuum with desirable performance.     

基于NPR效应及NOLM的多波长SOA光纤激光器

为了获得具有超窄波长间隔的稳定多波长输出,设 计并实验验证了一种基于非线性偏振旋转(NPR)效应及NOLM的多波长SOA光纤激光器。利用 SOA的NPR效应,将SOA与其他偏振器件组合引起强度相关损耗(IDL)效应,从而抑制SOA均 匀加宽线宽内的模式竞争,实现稳定的多波长输出。Lyot-sagnac滤波器作为波长选择器件 ,选用71 m长保偏光纤(PMF)得到超窄波长间隔。另外NOLM作为功率 均衡器进一步抑制了模式竞争效应并且实现了功率均衡,提高了边模抑制比(SMSR)。通过调 节偏振控制器(PCs),最终在室温下实现了稳定且功率均衡的多波长输出,10 dB带宽内输出的波长数量为184,波长间隔为0.08 nm,SMSR高达22 dB。该激光器可作为DWDM光通信系统 中的光源。     

Optical power budget enhancement in next-generation DDO-OFDM-based optical access networks using square root module

A passive optical network based on orthogonal frequency division multiplexing (OFDM-PON) gives improved performance for high speed optical access network due to its greater resistance to fiber dispersion and higher bandwidth efficiency. In optical fiber communication, chromatic dispersion (CD) is a linear distortion in fiber, but it is converted into nonlinear distortion due to square-law characteristic of photo diode detector at the receiver side resulting in degradation of performance. To compensate for this nonlinear distortion, we proposed to use a linearized receiver circuit with square root module (SRM) device which can improve the performance of system in terms of CD tolerance. In this paper, we have analytically analyzed the performance of OFDM-PON system with and without SRM device for direct-detection optical OFDM-PON (DDO-OFDM-PON) system. At BER of \(10^{-3}\), which is the limit of forward error correction, there is 11.1 and 13.5 dB improvement in optical budget with SRM for downstream and upstream direction, respectively, as compared to conventional DDO-OFDM-PON system.     

Five-port silicon optical router based on Mach-Zehnder optical switches for photonic networks-on-chip

With the continuous development of integrated circuits, the performance of the processor has been improved steadily. To integrate more cores in one processor is an effective way to improve the performance of the processor, while it is impossible to further improve the property of the processor by only increasing the clock frequency. For a processor with integrated multiple cores, its performance is determined not only by the number of cores, but also by communication efficiency between them. With more processor cores integrated on a chip, larger bandwidths are required to establish the communication among them. The traditional electrical interconnect has gradually become a bottleneck for improving the performance of multiple-core processors due to its limited bandwidth, high power consumption, and long latency. The optical interconnect is considered as a potential way to solve this issue. The optical router is the key device for realizing the optical interconnect. Its basic function is to achieve the data routing and switching between the local node and the multi-node. In this paper we present a five-port optical router for Mesh photonics network-on-chip. A five-port optical router composed of eight thermally tuned silicon Mach-Zehnder optical switches is demonstrated. The experimental spectral responses indicate that the optical signal-to-noise ratios of the optical router are over 13 dB in the wavelength range of 1525-1565 nm for all of its 20 optical links. Each optical link can manipulate 50 wavelength channels with the channel spacing of 100 GHz and the data rate of 32 Gbps for each wavelength channel in the same wavelength range. The lowest energy efficiency of the optical router is 43.4 fJ/bit.     

Eight-wavelength Er-Yb doped amplifier: combiner/splitter planarintegrated module

We report the successful operation of a pigtailed eight-wavelength planar integrated amplifying combiner. This device can be used in a splitter or in a combiner configuration. It consists in an 8×1 combiner and a 5.5-cm-long Er-Yb doped waveguide amplifier. The module provides net gain simultaneously to the eight combined wavelengths in the 1531-1546-nm optical bandwidth. This module has been incorporated in an 8×2.5 Gb/s wavelength-division-multiplexed (WDM) system. The central wavelength was 1535 nm and the channel spacing was 1 nm. Negative penalty for bit-error-rate performances (BER<10^-10) has been measured for each wavelength. The results of the system performance demonstrate the potential of the ion-exchange technology in providing cost effective integrated optic solutions for WDM networks applications