Analysis of polymer electro-optic microring resonator switches

The structure and the principle for the polymer electro-optic microring resonator (MRR) switch are proposed as well as the transfer functions. The structural parameters are optimized; the transmission characteristics are analyzed including the output power, switching time, switching voltage, insertion loss, and crosstalk. When the operation voltage is 0 V, the insertion loss and crosstalk are ∼1.2 and −20.2 dB, respectively; when the operation voltage is 10.0 V, those are ∼0.35 and −20.0 dB, respectively. Furthermore, a novel method is presented for analyzing time-domain response of the device and the switching time is determined to be ∼10.71 ps. These results indicate the favorable switching functions of the designed device.     

A novel accelerometer based on microring resonator

A novel microring resonator accelerometer is proposed. It is realized by a suspended straight waveguide coupled with a microring resonator. Under the external acceleration, the coupling coefficient is a function of gap spacing between the two waveguides. The mathematical model of the sensing element is established. Both the finite element method and coupled mode theory are adopted to analyze and optimize the proposed structure. Simulation results show that the mechanical sensitivity is 0.015 μm/g with the working frequency below 500 Hz and cross-axis sensitivity less than 0.001%, which is promising in seismic related applications.     

基于单个半导体光放大器的高速多功能逻辑门

采用半导体光放大器(SOA)中的非线性效应可以实现多种多样的高速全光信号处理. 利用SOA的非线性效应(包括四波混频、交叉增益调制、瞬态交叉相位调制等)实现了多种功能的逻辑运算,包括“与”、“或非”、“同或”、“或”和“非”. 由于SOA用于全光信号处理的调制速率受到增益恢复时间较慢的限制而无法实现高速的信号处理,在SOA后面级联一个带宽为0.32nm的失谐滤波器可以提高SOA的工作速率,仅用一个SOA实现了40Gbit/s的多功能逻辑门. 关键词： 半导体光放大器 全光逻辑门 瞬态交叉相位调制     

基于细菌视紫红质光子逻辑门的实验研究

研究了基于细菌视紫红质(简称BR或菌紫质)变种材料D96N的3种光逻辑操作.在633nm激发光照射下，菌紫质分子会被激发到M态，处于M态的菌紫质对412nm的紫光呈较大吸收，会抑制同时入射的紫光.选择合适的紫光强度，通过CCD观测被抑制的412nm检测光透射强度分布，模拟了“非”、“或非”、“与非”几种基本的光子逻辑操作. 关键词： 细菌视紫红质 光子逻辑门 互补抑制     

Ultracompact electro-optic phase modulator based on III-V-on-silicon microdisk resonator

A novel ultracompact electro-optic phase modulator based on a single 9 μm-diameter III-V microdisk resonator heterogeneously integrated on and coupled to a nanophotonic waveguide is presented. Modulation is enabled by effective index modification through carrier injection. Proof-of-concept implementation involving binary phase shift keying modulation format is assembled. A power imbalance of ～0.6 dB between both symbols and a modulation rate up to 1.8 Gbps are demonstrated without using any special driving technique.     

基于半导体材料微纳波导全光逻辑门的研究进展

全光逻辑门是全光计算以及全光信号处理系统中关键的光子器件.随着互补金属氧化物半导体(COMS)工艺的发展,基于半导体材料微纳波导全光逻辑门已经成为集成光学领域中的重要方向;尤其是硅基光子集成器件在近些年成为了国际研究热点.文章主要对基于绝缘体上的硅(SOD)和Ⅲ-Ⅴ族化合物材料不同波导结构(马赫-曾德尔干涉仪(Mach-Zehnder interferometer)微环谐振腔和条形波导结构)的全光逻辑门的研究进展进行了介绍,并且在器件的工作速率和功耗方面,分别对上述基于SOI和Ⅲ-Ⅴ族化合物材料三种不同波导结构的全光逻辑门进行了分析和比较.     

基于半导体材料微纳波导全光逻辑门的研究进展

全光逻辑门是全光计算以及全光信号处理系统中关键的光子器件.随着互补金属氧化物半导体(CMOS)工艺的发展,基于半导体材料微纳波导全光逻辑门已经成为集成光学领域中的重要方向;尤其是硅基光子集成器件在近些年成为了国际研究热点.文章主要对基于绝缘体上的硅(SOI)和Ⅲ-Ⅴ族化合物材料不同波导结构（马赫-曾德尔干涉仪(Mach-Zehnder interferometer)微环谐振腔和条形波导结构）的全光逻辑门的研究进展进行了介绍,并且在器件的工作速率和功耗方面,分别对上述基于SOI和Ⅲ-Ⅴ族化合物材料三种不同波导结构的全光逻辑门进行了分析和比较.     

Photonic logic NOR gate based on two symmetric microring resonators

We demonstrate an all-optical NOR logic gate based on symmetric GaAs-AlGaAs microring resonators whose resonances are closely matched. Two input pump data streams are tuned close to one resonance of the symmetric microrings to switch a probe beam tuned to another resonance by two-photon absorption. The switching energy of the gate is 20 pJ/pulse, and the switching window is 40 ps, limited by the carrier lifetime. The use of two rings provides for better cascading in photonic logic circuits because of the higher number of available ports.     

Trapped-ion quantum logic gates based on oscillating magnetic fields

Oscillating magnetic fields and field gradients can be used to implement single-qubit rotations and entangling multiqubit quantum gates for trapped-ion quantum information processing (QIP). With fields generated by currents in microfabricated surface-electrode traps, it should be possible to achieve gate speeds that are comparable to those of optically induced gates for realistic distances between the ion crystal and the electrode surface. Magnetic-field-mediated gates have the potential to significantly reduce the overhead in laser-beam control and motional-state initialization compared to current QIP experiments with trapped ions and will eliminate spontaneous scattering, a fundamental source of decoherence in laser-mediated gates.     

All-optical logic gates and a half-adder based on lithium niobate photonic crystal micro-cavities

All-optical logic gates including AND, XOR, and NOT gates, as well as a half-adder, are realized based on twodimensional lithium niobate photonic crystal(PhC) circuits with Ph C micro-cavities. The proposed all-optical devices have an extinction ratio as high as 23 dB due to the effective all-optical switch function induced by twomissing-hole micro-cavities. These proposed devices can have potential implementation of complex integrated optical functionalities including all-optical computing in a lithium niobate slab or thin film.     

光致异构全光逻辑门理论与实验研究

基于双光抽运探测模型，利用偶氮苯聚合物光致异构和光致双折射效应，建立了全光逻辑门的理论分析模型，提出了一种新颖的全光逻辑门设计方案.该方案基于输入抽运光和信号光的强度或偏振态，设计了“与”门、“或”门、“异或”门和“异或非”门等基本功能的全光逻辑门.以掺杂分散红1(DR1)的聚甲基丙烯酸甲酯(PMMA)薄膜为样品进行实验，得到了比较好的逻辑门运算实验结果，与理论分析相符合.     

All-optical integrated logic gates based on intensity-dependent transverse modal coupling

We present a study of the spatial propagation of light in a third order planar step-index waveguide with a transverse parabolic width film. By using the Lagrangian formalism, the width and phase evolution of a Gaussian beam has been completely described showing both the refractive contributions of the lens-like waveguiding geometry and self-focusing nonlinearity. As a result of this study, we have proposed the design of a new kind of integrated all-optical devices which, by means of the spatial beam power modulation and its influence on the transverse modal coupling can operate as phase-insensitive AND, OR and XOR logic gates.     

Transmission and group delay in a double microring resonator reflector

We present a microring resonator scheme for an optical reflector in which two microrings are coupled to two bus waveguides, to produce reflected signal at the input port. In this system, a single narrow reflected peak with maximum reflectivity near 100% in a wide spectral range due to the Vernier effect are achieved. We also investigate versatile reflection, transmission spectra and group delay characteristic. These effects are useful for applications in ring resonator-based photonic devices such as all-optical single wavelength tunable laser end mirrors, reflective wavelength switching, reflective filter and dual-wavelength delay line.     

Ultrasmall optical logic gates based on silicon periodic dielectric waveguides

An ultrasmall silicon periodic dielectric waveguides-based multimode interference all-optical logic gate has been proposed. The device consists of three 205 nm wide single-mode input waveguides, a 1.1 μm wide and 5.5 μm long multimode interference waveguide, and three 205 nm wide single-mode output waveguides. The total length and width of the device are 13.7 μm and 3.2 μm, respectively. By changing the states of the input optical signals and/or control signals launched into the device, multifunctional logic functions including OR, NAND, NOR, and NOT gates are performed, and each logic function can be realized at a specific output waveguide in accordance with the launched control signals. The ultrasmall multifunctional logic device has potential applications in high density photonic integrated circuits.     

Dual-band optical filter based on a single microdisk resonator

We propose and experimentally demonstrate a dual-band optical filter based on a single microdisk resonator. An analytical model is built based on the transfer matrix method and is applied to simulate the properties of such a device. Competition and interference of the dual modes in the resonator lead to dual-band filtering with high isolation. As the finite-difference time-domain simulation illustrates, two low-order resonant modes can be effectively triggered by optimizing the waveguide width and spacing gap between the compact resonator and waveguides. In experiment, a double side-coupled microdisk resonator was fabricated on a nanophotonic silicon-on-insulator platform, and dual-band bandpass filtering is realized with an optical isolation higher than 20 dB and an insertion loss lower than 2 dB. The experimental results agree well with our modeling results.     

Optimization and analysis of series-coupled microring resonator arrays

In terms of the coupled mode theory and transfer matrix technique, novel formulas of the amplitude coupling ratios and transfer functions are presented for a series-coupled microring resonator (MRR) array. By using these formulas, parameters are optimized, and transmission characteristics including the transmission spectrum and the insertion loss are analyzed for a SiN/SiO₂ series-coupled MRR array on Si substrate. The box-like spectral response is successfully obtained owing to the proper selection of the amplitude coupling ratio between the channel and the ring, and that between adjacent rings, as well as the number of series-coupled rings.     

基于串联哑铃型微环谐振腔的二维相干光码分多址编解码器

利用微环谐振腔阵列进行光码分多址编解码过程中,微环谐振腔反射谱的自由频谱宽度(FSR)范围制约该系统用户容量的提升.本文提出了一种新型的基于游标效应的串联哑铃型微环谐振腔光编解码器.利用Matlab建立了半径分别为40μm-30μm-40μm的哑铃型微环谐振腔光编解码器模型.详细分析了光反射谱伪模抑制与耦合系数的关系,研究了耦合系数、码片速率对串联哑铃型微环谐振腔光编解码器性能的影响.结果表明,与半径分别为40μm-40μm-40μm的传统串联微环谐振腔编解码器相比,哑铃型微腔编解码器FSR值扩大了4倍.理想情况下,用户容量可呈指数增长.同时,互相关峰值比(P/W)与自相关峰值旁瓣比(P/C)分别提高了约33%和8%.     

Simultaneous measurement of refractive index and temperature using a microring resonator

An approach to the simultaneous measurement of refractive-index(RI) and temperature changes using optical ring resonators is proposed and theoretically demonstrated.With a liquid-core silica ring resonator as an example,two different-order whispering gallery modes(WGMs) might differ in not only RI but also temperature sensitivities.Thus,a second-order sensing matrix should be defined based on these WGMs to determine RI and temperature changes simultaneously.The analysis shows that the RI and temperature detection limits can be achieved on the order of 10 7 RI unit and 10 3 K at a wavelength of approximately 780 nm.     

Triple-band metamaterial absorber based on single resonator

The single resonator generally reveals a single absorption band, and the resonators with different sizes or shapes have to be arranged in order to achieve multi-absorption bands. We propose the triple-band metamaterial absorber by utilizing only single resonator. Meta-atoms are made of the toothed-wheel shape metallic pattern and a continuous metallic plane, separated by a dielectric layer. The first and the third absorption bands are induced by the fundamental and the third-harmonic magnetic resonances, respectively, and the second absorption band is induced by the magnetic resonance relevant to two grooves. In addition, the diffraction peak appears between the second and the third absorption bands, due to the surface currents which are separated between the upper and the lower metallic pattern parts. The proposed structure is scalable to smaller size for the infrared and the visible regimes.