All-Optical Bistability in Grating Coupling to Nonlinear Waveguide

１ＩｎｔｒｏｄｕｃｔｉｏｎＮｏｎｌｉｎｅａｒｄｉｓｔｒｉｂｕｔｅｄｃｏｕｐｌｉｎｇｔｈｒｏｕｇｈｐｒｉｓｍｔｏｎｏｎｌｉｎｅａｒｐｌａｎａｒｗａｖｅｇｕｉｄｅｈａｓｂｅｎｉｎｖｅｓｔｉｇａｔｅｄａｎｄｔｈｅｃｈａｒａｃｔｅｒｓｏｆｏｐｔｉｃａｌｌｉ...     

非线性一维光子晶体波导光双稳

利用非线性折射率系数较大且非线性时间响应较快的CdS_xSe_1-x玻璃为材料,设计并制备了非线性一维光子晶体波导光双稳器件,该器件的折射率空间分布呈正弦形式。实验测得双稳开关的阈值功率密度为1.60×10⁵W/cm²,开关时间为63ps。采用时域有限差分方法讨论了光子晶体带隙随入射光强变化而移动的情况,随着入射光功率密度的增加,光子晶体的带隙中心向短波方向移动。同时计算了该器件的双稳特性,理论计算得到双稳开关的阈值功率密度为1.40×10⁵W/cm²,开关时间约为50ps。获得了理论与实验基本一致的结果。     

非线性介质中强光对弱光聚焦的控制研究

从理论和实验上分析了强光控制弱光脉冲聚焦的方法, 该方法可以灵活地控制弱光的聚焦过程和特性. 通过研究两光束共同传输, 利用强抽运光在相互作用时为弱探测光提供诱导非线性效应, 从而使弱探测光发生聚焦. 得到了在抽运光保持不变情况下探测光的解析解, 并在实验上得到验证. 进一步研究了强抽运光对弱探测光焦点位置的影响. 结果显示: 通过改变抽运光功率、束宽能够有效地控制弱探测光的聚焦过程和焦点位置. 关键词： 诱导聚焦 自聚焦 非线性折射率     

Theoretical Design of a Pump‐Free Ultrahigh Efficiency All‐Optical Switching Based on a Defect Ring Optical Waveguide Network

A theoretical design of a defect ring optical waveguide network is proposed to construct a pump‐free ultrahigh efficiency all‐optical switch. This switch creates ultrastrong photonic localization and causes the nonlinear dielectric in the defect waveguide to intensely respond. At its ON state, this material defect without Kerr response helps to produce a pair of sharp pass bands in the transmission spectrum to form the dual channel of the all‐optical switch. When it is switched to its OFF state, the strong Kerr response induced refractive index change in the high nonlinear defect waveguide strongly alters the spectrum, leading to a collapse of the dual channels. Network equation and generalized eigenfunction method are used to numerically calculate the optical properties of the switch and obtain a threshold control energy of about 2.90 zJ, which is eight orders of magnitude lower than previously reported. The switching efficiency/transmission ratio exceeds 3× 10¹¹, which is six orders of magnitude larger than previously reported. The state transition time is nearly 108 fs, which is approximately two orders of magnitude faster than the previously reported shortest time. Furthermore, the switch size can be much smaller than 2.6 µm and will be suitable for integration.     

Bit Constraints Analysis of Multihop All-Optical Networks with Deflection Routing

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｏｏｖｅｒｃｏｍｅｔｈｅｅｌｅｃｔｒｏｎｉｃｂｏｔｌｅｎｅｃｋｏｆｃｏｎｖｅｎｔｉｏｎａｌｏｐｔｉｃａｌｐａｃｋｅｔｓｗｉｔｃｈｉｎｇｎｅｔｗｏｒｋｓ，ａｌｏｐｔｉｃａｌｐａｃｋｅｔｓｗｉｔｃｈｉｎｇｎｅｔｗｏｒｋｓａｒｅ...     

利用非线性光学环路镜实现多个波长的同时变换

利用非线性光不路镜（ＮＯＬＭ）成功地实现了多个波长的同时变换,最大波长变换间距大于２５ｎｍ。实验系统中采用增益开关分布反馈半导体激光器（ＧＳ ＤＦＢ－ＬＤ）产生的超短光脉冲作为控制光,频谱分割法得到多波长激光作为信号光。改变控制光的输入功率或非线性光学环路镜中的偏振控制器的偏振方向能够改变不同变换波长信号的性能。     

Design and Evaluation of an N:N Optical Coupler Using an Integrated Waveguide Mirror

We proposed and fabricated an N:N optical coupler using an integrated waveguide mirror. Optical circuits can be miniaturized with small bending by reflecting mirrors. The parabolic curve was applied to the mirror shape because it was necessary to collimate the reflected beam so as to distribute the input light to the output waveguides. We fabricated the 8:8 optical coupler using silica waveguide. The chip size was about 7mm x 15mm. The excess loss of the device was about 8 dB larger than simulation results calculated using beam propagation method. The dependence on the wavelength and polarization was about 0.4 and 0.15 dB, respectively. The excess loss was mainly attributed to the mirror tilt and will be reduced by optimizing the etching conditions to decrease the mirror tilt angle.     

光波导氨敏传感器的研究

提出了一种新型的光波导氨敏传感器,将光波导中消逝波理论与纳米多孔薄膜技术相结合,在玻璃薄膜光波导上制备一层纳米TiO2多孔薄膜,并将氨敏试剂（BTB）固定在纳米TiO2多孔薄膜中,利用导波光的消逝场实时地探测敏感薄膜对导波光的吸收,实现了对氨气的探测,检测下限达到1ppm。同时对比了致密敏感薄膜和多孔敏感薄膜对氨气的响...     

环形光纤激光器中的半导体光波导调制器

对环形光纤激光器中的半导体光波导调制器进行了理论研究，结果表明，光纤环中的偏振控制器对光的偏振态的控制以及半导体光皮导对光的偏振态的调节构成了激光器的主要调制机理，为环形光纤激光器的自调Ｑ及锁模的新机制提供了理论依据。     

用转移矩阵法研究LNN型非线性平面光波导

用转移矩阵法数值分析了芯区和衬底为非线性介质、覆盖层为线性介质结构平面光波导的传播特性,包括TM的模场分布和功率与有效折射率之间关系的分析.解析地表达了模式本征方程和功率分布,对非线性介质中电场强度与介质非线性系数的关系进行了研究.计算结果表明,TM的模场分布和功率与有效折射率及介质的非线性系数有关.     

光波导振荡场传感器

针对消逝场传感器的不足,提出了一种传感介质处于波导芯层,且以超高阶导模为探针的光波导振荡场传感器.由于其波导芯层处于功率密度极高的振荡场区域,而超高阶导模又具有对芯层参数极为灵敏的性质,因此这种新型传感器的灵敏度大大增强.实现了超越消逝场传感器灵敏度极限值几个量级的位移传感器.     

X－型波导全光开关的优化设计

依据耦合模理论与光束传播法（Ｂｅａｍｐｒｏｐａｇａｔｉｏｎｍｅｔｈｏｄ），提出了由Ｘ结波导到交叉波导的系列化全光开关设计。此设计方法可以对不同的材料（自聚焦、自散焦）、不同的非线性折射率和波长等进行波导全光开关优化设计。     

光束束宽对自散焦介质中诱导光束聚焦的影响

影响自散焦介质中诱导光束聚焦过程的方程参量和初始条件共有5个，即两光束波长比(方程参量)、抽运光和信号光的初始振幅、两光束初始束宽比和两光束中心初始间距。通过数值计算讨论了初始束宽比在不同初始光束间距和波长比情况下对信号光聚焦过程的影响，得到了信号光聚焦效果的最佳初始参量条件。从而实现了对影响自散焦介质中诱导光束聚焦过程5个参量的完整详细研究。     

光脉冲在孔硅波导中的非线性调制过程与波形特征分析

研究了具有不同中心载波波长的高功率双脉冲在微纳孔硅波导中的非线性光学过程和输出脉冲在时域与频域的波形特征。结果表明,由于双光子吸收、自由载流子吸收、自由载流子色散、自相位调制和交叉相位调制的非线性效应作用,在波导输出端,目标脉冲的不对称时域和频域脉冲波形被观察,而且脉冲波形的改变依赖于注入功率、初始宽度、波导长度和脉冲时延参数。     

基于光纤马赫-曾德尔干涉仪的强度测量研究

根据光外差检测原理，分析得到干涉测量适用于信号光强小于参考光强的探测，直接测量适用于信号光强大于参考光强的探测的结论。利用自制的全光纤马赫-曾德尔干涉仪系统，对位移信号进行了测量。实验结果表明：当位移信号较小时，干涉测量的灵敏度分别为62．068μW／mm和9．90mV／mm，而非干涉测量的灵敏度分别为4．30μW／mm和0．35mV／mm；当位移信号较大时，干涉测量的灵敏度分别为2．643mV／mm和0．055mV／mm，非干涉测量的灵敏度分别为12．326mV／mm和4．194mV／mm，测量结果与分析得到的结论一致。对于光纤干涉仪强度调制检测的应用具有参考价值。     

控制色散的波导结构分析

色散控制在光纤通信中越来越重要,从低速率到高速率,从单波长SDH到多波长DWDM,色散控制要求越来越严.通过对不同应用的光纤波导结构的制造、性能测试和分析,指出了波导结构设计与光纤衰减、模场直径、弯曲损耗和波导色散等的关系.这些实践经验可以指导光纤的设计与制造.     

Nonlinear All-Optical Switching Device by Using the Spatial Soliton Collision

We propose a new nonlinear all-optical switching device by using the spatial solitons collision. This is 1 × N switching device controlled by two control beams. The numerical results show that this device could really function as a 1 × N all-optical switching device. This device is a potential key component in the application of optical signal processing and optical computing systems.     

Nonlinear All-Optical Switching Device by Using the Spatial Soliton Collision

We propose a new nonlinear all-optical switching device by using the spatial solitons collision. This is 1 × N switching device controlled by two control beams. The numerical results show that this device could really function as a 1 × N all-optical switching device. This device is a potential key component in the application of optical signal processing and optical computing systems.     

制备全光功能开关的多量子阱材料设计

采用有效质量框架下一维有限深势阱模型对InGaAsP多量子阱的组分和阱宽之间的关系进行了计算,利用更符合实验结果的Harrison模型来计算带阶,分别就晶格匹配和应变补偿两种情况进行了比较计算,最后根据要制作的全光功能开关的性能指标对计算结果进行了选择,得到最适合于制作光开关的材料.     

平板波导的非线性耦合

给出了两个平板波导耦合成的定向耦合器,当两波导的间隙为克尔型非线性人质时耦合系数与导波功率的关系的计算公式与计算步骤,给出了耦合区为自聚焦介质及自散焦介质两情况的计算实例,并对计算结果进行了讨论