Electro-optic polymer assisted optical switch based on silicon slot structure

One kind of electro-optic polymer assisted Mach-Zehnder optical switch based on silicon slot structure is presented in this paper. The interference arms of the switch are slot structures instead of regular single-mode waveguides. By filling electro-optic material in the void slot of the arms, direct electro-optic modulation can be introduced. Theoretical model and detailed analysis are given in this paper. The length-independent product V_πL is about 74 mV cm when slot width is 100 nm, and 37 mV cm when slot width is 50 nm, when the polymer with a electro-optical coefficient of γ₃₃ = 130 pm/V is assisted. An ultralow energy consumption of only 37 fJ/bit is achievable, and the turn-on time of the switch is less than 1.5 ps.     

Cosine bend-linear waveguide digital optical switch with parabolic heater

A new digital optical switch (DOS) with large branching angle and short device length that exhibits low crosstalk and low power consumption is demonstrated. The Y-branch shape was optimized by introducing constant effective refractive index difference between branches (ΔN_eff) along the propagation direction through beam propagation method (BPM) scheme. To provide decreasing local branching angle that results in the improvement of the crosstalk, two modified cosine bend was introduced to form the Y-branch. The modified cosine branch was then connected to a linear branch. The heater electrode was optimized so that the temperature fields induce a constant ΔN_eff to satisfy initial assumption in designing the Y-branch shape. With branching angle of 0.299° and device length of only 5 mm, the simulation shows that the device could exhibits crosstalk of −33 dB at calculated required power of only 26 mW.     

Athermal silicon arrayed waveguide grating with polymer-filled slot structure

In this paper, an athermal silicon arrayed waveguide grating (AWG) with the assistance of a polymer-filled slot structure is proposed. Arrayed slot waveguides were used to replace arrayed silicon photonic wires (SPWs). By carefully controlling the temperature dependence of the effective index of the polymer-filled slot waveguides, the athermal silicon AWG is realized. Analysis shows that the center wavelength shift of the AWG can be down to 0.14 pm/°C.     

Efficient design of silicon slot waveguide optical modulator

An optimal design of a slot waveguide is presented for realizing an ultrafast optical modulator based on a 220 nm silicon wafer technology. The recipe is to maximize the confinement and interaction between optical power supported by the waveguide and electric field applied through metallic electrodes. As height of waveguide is fixed at 220 nm, the waveguide and slot width are optimized to maximize the confinement factor of optical power. Moreover, metal electrodes tend to make the waveguide lossy, their optimal placement is calculated to reduce the optical loss and enhance the voltage per unit width in the slot. Performance of an optimally designed slot waveguide with metal electrodes as ultrafast modulator is also discussed.     

数字光开关网络中四功能交换开关光学Omega网络

本文提出了一种用于数字光开关网络中，四功能交换开关光学Ｏｍｅｇａ网络。文中详细地阐述了用液晶空间光调制方法实现光学四功能交换开关，和Ｏｍｅｇａ互连网络的原理，并给出了光学系统和实验结果。     

Sub-nanosecond optical switch based on silicon racetrack resonator

<正>We experimentally demonstrate a small-size and high-speed silicon optical switch based on the free carrier plasma dispersion in silicon.Using an embedded racetrack resonator with a quality factor of 7400,the optical switch shows an extinction ratio exceeding 13 dB with a footprint of only 2.2×10~(-3)mm~2.Moreover,a novel pre-emphasis technique is introduced to improve the optical response performance and the rise and the fall times are reduced down to 0.24 ns and 0.42 ns respectively,which are 25%and 44%lower than those without the pre-emphasis.     

pH-controlled silicon nanowires fluorescence switch

Covalently immobilizing photoinduced electronic transfer (PET) fluorophore 3-[N, N-bis(9-anthrylmethyl)amino]-propyltriethoxysilane (DiAN) on the surface of silicon nanowires (SiNWs) resulted a SiNWs-based fluorescence switch. This fluorescence switch is operated by adjustment of the acidity of the environment and exhibits sensitive response to pH at the range from 8 to 10. Such response is attributed to the effect of pH on the PET process. The successful combination of logic switch and SiNWs provides a rational approach to assemble different logic molecules on SiNWs for realization of miniaturization and modularization of switches and logic devices.     

Atom-loss-induced quantum optical bi-stability switch

We investigate the nonlinear dynamics of a system composed of a cigar-shaped Bose-Einstein condensate and an optical cavity with the two sides coupled dispersively.By adopting discrete-mode approximation for the condensate,taking atom loss as a necessary part of the model to analyze the evolution of the system,while using trial and error method to find out steady states of the system as a reference,numerical simulation demonstrates that with a constant pump,atom loss will trigger a quantum optical bi-stability switch,which predicts a new interesting phenomenon for experiments to verify.     

多间隙气体开关光纤诊断

介绍了一套用于多间隙气体开关光学诊断的光纤探测系统,该系统主要由光纤阵列探测器和沉入式日盲型光纤探测器构成。用该系统研究了多间隙气体开关的详细击穿过程,并分析触发电压、气压及紫外光预电离对开关性能的影响。光纤阵列探测器定时精度小于0.6 ns,脉冲响应3.2 ns;日盲型光纤探测器光谱响应为260~320 nm,通过实验可知,气体开关击穿次序为:3#-2#-1#-4#-5#-6#,统计时延和过压击穿时延占主要部分;提高开关的触发电压、降低开关的工作气压,主要影响开关击穿过程的前半部分,从而降低开关的击穿抖动;如果能够产生强度稳定的紫外光,可以改善开关的抖动性能。     

High-speed and broad optical bandwidth silicon modulator

A high-speed silicon modulator with broad optical bandwidth is proposed based on a symmetrically configured Mach–Zehnder interferometer.Careful phase bias control and traveling-wave design are used to improve the high-speed performance.Over a broadband wavelength range,high-speed operation up to 30 Gbit/s with a 4.5 dB–5.5 dB extinction ratio is experimentally demonstrated with a low driving voltage of 3 V.     

Dispersion modified slot optical waveguides

Advent of slot waveguide structures had opened a new era where light can be confined in low index slot guarded by high index slabs. Already in use SOI slot waveguides (contrast ratio is 2.42) have two distinct properties over the conventional waveguides, i.e. high E-field amplitude, optical power, optical intensity in low index materials, and strong E-field confinement localized to nanometer-size low index regions. We hereby propose a low refractive index contrast ratio slot waveguide structure (ratio is 1.18) comprising of commercially available glass material. Novelty lies in showing high E-field amplitude, optical power, optical intensity, and strong E-field confinement in low index slot regions despite of lowest ever reported contrast ratio. A systematic numerical study on the higher order dispersion characteristics of the widely studied SOI-based slot structure and of our proposed low refractive index contrast slot structure is carried out. It has been demonstrated that low refractive index contrast ratio slot optical waveguide GVD properties are quite different than SOI slot optical waveguide. The less normal dispersion existing in this kind of waveguide could have an impact on their applications in various nonlinear or linear applications.     

光梯度力驱动的纳米硅基光开关

通过一道光改变另一道光的传输路线是光子集成网络中重要而长远的目标, 然而, 由于硅材料的光学非线性较弱, 在硅材料上实现开关的全光控制难以实现. 因此本文提出了一种由光梯度力驱动的纳米硅基光开关, 实现了硅基光开关的全光控制. 该光开关由一个部分悬空的微环谐振器和一个交叉波导结构构成, 当通入一道控制光时, 悬空的微环谐振器在光梯度力的作用下发生弯曲, 微环谐振器的谐振波长随之发生变化, 从而实现光信号的传输路线发生改变. 该光开关利用纳米光子制造技术在标准绝缘体上硅晶圆上制造, 实验数据得出其最小消光比为10.67 dB, 最大串扰为 -11.01 dB, 开关时间分别为180 ns和170 ns. 该光开关具有尺寸小, 响应速度快, 低损耗和可拓展等优点, 在片上集成光路、高速信号处理以及下一代光纤通信网络中具有潜在应用.     

集成双波导半导体光放大器光开关实现波长转换的理论研究

建立了基于集成双波导半导体光放大器的光开关(ITG-SOA-Switch)的理论分析模型.与半导体光放大器(SOA)的特性相比较表明，由于ITG-SOA-Switch合并了多种物理效应，故其静态增益饱和曲线在饱和功率点附近具有大幅度陡峭下降的独特性质.理论分析和10 Gbit/s波长转换模拟结果显示，恰当地选择输入抽运光的功率范围，ITG-SOA-Switch波长转换器输出转换光的消光比特性较之输入抽运光会有显著的改善. 关键词： 波长转换 半导体光放大器 集成双波导半导体光放大器 光开关     

激光点火系统用高功率光纤光开关

仿真和实验研究了一种控制Nd:YAG脉冲激光能量通断的光纤直接连接型光开关。建立光纤耦合模型,分析了光纤对准误差中对耦合效率的影响,其中横向偏移的影响最显著。采用微机电系统V型槽固定光纤,微小型凸轮作为制动器,步进电机驱动凸轮旋转,微小型凸轮与移动光纤相切,带动光纤移动,实现两光纤的错开和对准。制造了这种高功率直接连接型光纤光开关原理样机,并进行了主要性能测试。测试结果表明,这种光开关能够满足激光点火系统的大容量、高隔离度的要求。     

Dispersion characteristics of SOI-based slot optical waveguides

The invention of the slot waveguide had enabled a number of interesting novel linear or nonlinear optical applications by guiding light in nanometers-wide low index slots guarded by high-index slabs. As one of its key characteristics, the low modal index for this kind of waveguides has been demonstrated by many studies. However, their higher order dispersion properties have not been thoroughly investigated yet, while the growing size and complexity of these devices and their potential nonlinear optical applications involving short optical pulses demand further understanding in their dispersion behavior. We here carry out a numerical study on the higher order dispersion characteristics of the SOI-based slot structures around the 1550 nm wavelength. Our results show that they could have significantly different second order dispersion properties in contrast to the traditional channel SOI waveguides. Their potentially large normal dispersion could have an impact on various nonlinear or linear applications. The relationship between the dispersion performance and the waveguide design is also investigated, and the results could show further venues to optimize or control the dispersion properties of such waveguides.     

基于Norland紫外固化胶的热光开关器件

采用新型聚合物材料Norland紫外固化胶（NOA）制备了聚合物M-Z型热光开关器件。对NOA薄膜材料的光学性质进行了表征,采用感应耦合等离子体（ICP）方法制备出形貌良好的波导器件。测得在1 550 nm波长下,长2.2 cm的直波导插入损耗为8.3 dB。在电极上施加直流信号,测得热光开关的消光比为11 dB,驱动功率为85 mW。引入直流偏置网络,获得了器件的开关特性曲线,测得开关器件的上升时间为1.085 ms,下降时间为489.5μs。实验结果表明：NOA材料在热光开关及其它聚合物光波导集成器件的制备中具有很大的应用潜力。     

Electrically controlled optical switch in the hybrid opto-electromechanical system

To promote the future quantum information technologies, we demonstrate an electrically driven optical switch based on quantum interference in a hybrid opto-electromechanical system, which consists of an opto-mechanical cavity and an external electric circuit. The key element of our scheme is a moveable mirror of cavity as a charged mechanical oscillator capacitively coupled to a fixed charged plate in a variable capacitor. By adjusting the voltage of the capacitor, the displacement of the moveable mirror is modulated, then the cavity field can be electrically turned on or off due to the detuning of the cavity. Based on the cavity induced transparency, the transparency window can be electrically switched on or off by turning on or off the cavity field. Therefore, the susceptibility of the medium in the cavity can be electrically controlled, i.e., the scheme of the electrically controlled absorption switching can be demonstrated. This electrically driven optical switch will excite a development trend and implementation prospect towards the integration and miniaturization of quantum module device in a chip.     

Flexible integration of optical switch with optical power splitting and attenuating functions for optical fiber-based networking applications

A flexible integration of optical switch with optical power splitting and attenuating functions has been proposed to optimally serve optical fiber-based networking applications. In this switch, an etched binary-slope sidewall reflector is electrostatically actuated in and out of the plane to manipulate optical signals between input and output optical fibers. The fabrication process is a simple combination of a bulk-silicon micromachining process and silicon-to-glass anodic bonding where fiber alignment grooves, reflectors and actuators are fabricated on the same silicon substrate. Ball-lensed fibers are assembled with the device to achieve high coupling efficiency. Performances of the fabricated devices are measured and discussed. The switching time is less than 9 ms at 31 V. The excess loss of the device is less than 3 dB and the controllable attenuation range is up to 38 dB at 139 V, respectively. Moreover, polarization-dependent loss is less than 0.7 dB in the whole attenuation and splitting range.     

Observation of V-type electromagnetically induced transparency and optical switch in cold Cs atoms by using nanofiber optical lattice

Optical nanofiber (ONF) is a special tool to achieve the interaction between light and matter with ultralow power. In this paper, we demonstrate V-type electromagnetically induced transparency (EIT) in cold atoms trapped by an ONF-based two-color optical lattice. At an optical depth of 7.35, 90% transmission can be achieved by only 7.7 pW coupling power. The EIT peak and linewidth are investigated as a function of the coupling optical power. By modulating the pW-level control beam of the ONF-EIT system in sequence, we further achieve efficient and high contrast control of the probe transmission, as well as its potential application in the field of quantum communication and quantum information science by using one-dimensional atomic chains.