Dynamic path length changes in all-fiber mirrors: Transmission modulation

In this paper, we present a technique to modulate the transmission of an all-fiber mirror. This technique is based on the phase modulation of the light in the fiber loop, combined with the time delay between the clockwise and anticlockwise propagating beams. Using Jones calculus, a theoretical analysis has been carried out to describe the effects of static polarization changes and a dynamic phase modulation. An experimental all-fiber optical mirror has been constructed, and using a 1-MHz piezoelectric disc as the phase modulator, we demonstrate that it is possible to achieve either a 1-MHz or 2-MHz transmission modulation by adjusting the polarization state.     

The cascaded exponential-tapered multimode interference couplers based triplexer design for FTTH system

A novel compact triplexer, which consists of series cascaded exponential-tapered multimode interference couplers, is introduced in this paper. General self-image properties of the exponential-tapered multimode interference couplers are investigated thoroughly to fulfill the compact integrated triplexer. By combining four exponential-tapered MMI couplers, a novel compact 0.6 cm-long triplexer that is with ITU standard wavelength of 1310 nm, 1490 nm and 1550 nm for FTTH is achieved without requiring complicated design. And it can be fabricated by common planar lightwave circuit (PLC) technology. From the simulation results for wavelength of 1310 nm, 1490 nm and 1550 nm, the insertion losses are 0.34 dB, 0.9 dB and 1.17 dB, with isolations for each output waveguide ranging from 12.74 dB to 37.15 dB. The 3 dB passband widths for 1310 nm, 1490 nm and 1550 nm are 112.39 nm, 29.44 nm and 26.7 nm.     

一种新型全光开关

提出了一种用指数型变耦合系数定向耦合器同高斯型变耦合系数定向耦合器级联所构成的新型全光开关。理论分析及数值模拟均表明,它同用常系数定向耦合器级联所得的器件相比,具有一个很大的优点,即可以消除开关曲线在过开关区中的振荡,因而具有更好的开关特性;同时,它同用高斯型变耦合系数定向耦合器级联所得的器件相比,具有陡峭的动态开关区(即功率透过率从0逐渐升至1的区域)。综上所述,该级联耦合器更加适合于做全光开关,且在满足一定的开关曲线的要求下,可以通过改变各级联耦合器的参量以改变单元耦合器的数目。     

Asymmetrical optical fibre coupler for laser side pumping: optimization of its parameters and application in laser

The paper presents an optical fibre coupler with side coupling. The coupler is based on an active double clad fibre and a pumping fibre with an extended core. The optimization of the coupler’s parameters and the initial simulations results are presented. The coupler was used in a ring laser setup and multiwavelength operation with up to 25 wavelengths was achieved.     

A 1 × 2 optical switch using one multimode interference region

A 1 × 2 optical switch using only one multimode interference (MMI) region is designed and demonstrated in GaAs/AlGaAs. This design makes a single MMI region works as MMI coupler using paired interference at “off” state and symmetric interference at “on” state. By injecting a current of 110 mA, the measured on/off ratio and crosstalk are 23 dB and 33 dB, respectively in the demonstrated device with GaAs/GaAlAs.     

五甲川链上具有β,δ-次丙基桥链的二碳菁染料的合成及其在减色法彩色胶片感红层中的应用

合成了具有β,δ-次丙基桥链的八个二碳菁染料。照相性能试验表明,用β,δ-次丙基桥链五甲川染料,可以作为有效的感红增感剂。在青成色剂C-1存在下,用这些染料增感的乳剂与Rr1833比较,具有好的贮存稳定性。     

基于非线性定向耦合器的光二进制逻辑器件

本文提出了一种新的非双稳态光学逻辑器件,它由一个双端输入的非线性光波导耦合器产生相应的输入输出波形,再经过多级单端输入的非线性耦合器进行波形限幅和整形,以获得阶跃开关特性.通过理论计算说明适当选择输入条件,这种器件可以实现所有六种基本的二进制逻辑运算功能:与、或、与非、与或、异或和同或.     

Mechanophotonics: Flexible Single-Crystal Organic Waveguides and Circuits

We present the one-dimensional optical-waveguiding crystal dithieno[3,2-a:2′,3′-c]phenazine with a high aspect ratio, high mechanical flexibility, and selective self-absorbance of the blue part of its fluorescence (FL). While macrocrystals exhibit elasticity, microcrystals deposited at a glass surface behave more like plastic crystals due to significant surface adherence, making them suitable for constructing photonic circuits via micromechanical operation with an atomic-force-microscopy cantilever tip. The flexible crystalline waveguides display optical-path-dependent FL signals at the output termini in both straight and bent configurations, making them appropriate for wavelength-division multiplexing technologies. A reconfigurable 2×2-directional coupler fabricated via micromanipulation by combining two arc-shaped crystals splits the optical signal via evanescent coupling and delivers the signals at two output terminals with different splitting ratios. The presented mechanical micromanipulation technique could also be effectively extended to other flexible crystals.     

硅基光栅耦合器的研究进展

硅基光子集成芯片的研究近年来发展迅速, 已成为信息技术领域中最热门的研究方向之一, 光通信、光互连、光传感等相关研发应用机构高度关注其发展, 并积极介入. 硅基光子集成芯片中, 光栅耦合器作为光信号的输入和输出装置受到极大重视, 尤其在封装和测试等环节体现出极具价值的技术优势. 本文主要分析了光栅耦合器的工作原理、基本特性及国内外的发展现状和趋势, 同时也概括了本课题组近期在该方向上的研究成果. 关键词： 光栅耦合器 耦合效率 绝缘体上硅 光子集成