Passive Integrated Optical Components

Incoherent diffraction imagery formed by a polarizing microscopy with crossed polarizers is studied. Closed form solutions are obtained for the cumulative point spread function, the line spread function, and the edge spread function. Representative numerical results are displayed. The image of a bar target is also evaluated.     

面向硅基光互连应用的无源光子集成器件研究进展

光互连是突破传统微电子IC性能瓶颈的重要技术手段,对推进"后摩尔时代"微电子技术的发展和高性能计算技术的实现具有关键性意义。本文在归纳总结不同层次光互连结构特点的基础上,对片上光互连(on-chip or intra-chip optical interconnects)所涉及的若干种无源光子集成器件的设计制备及性能特点进行了分析介绍,这些器件包括SOI亚波长光子线波导、SOI光子晶体波导、MMI分束/合束器、微环/微盘谐振腔滤波器、光子晶体微腔耦合滤波器、光子晶体反射镜等,是硅基片上光互连的基本构成单元。本文对这些关键性光子集成器件的国内最新研究进展进行了报道。     

一种用于通信C波段的光轨节点无源集成芯片

光轨是一种新型光通信网络结构,具有交换粒度小、带宽利用率高等优点。本文提出一种应用于通信C波段的新型光轨节点无源集成芯片,支撑1 545 nm、1 550 nm和1 555 nm三个C波段波长的通信。该新型光轨节点无源集成芯片是一种基于SOI纳米波导材料的片上微器件系统,核心器件由基于微环谐振器的解复用器和基于马赫-泽德尔干涉仪的环加强型热光光开关构成。通过理论计算和软件仿真,分别分析了解复用器和光开关的光学和通信性能,结果显示微环解复用器3个波长信道的串扰分别为22.5 dB、16.9 dB和16.3 dB;光开关的消光比分别为16.6 dB、19.7 dB和21.5 dB;插入损耗分别为0.86 dB、0.85 dB和0.68 dB,功耗约为51 mW。     

All-optical Integrated Nonlinear Devices

Abstract

The field of third-order nonlinear integrated optics is reviewed, with emphasis on intensity-dependent phenomena for all-optical device applications. The most relevant material issues are briefly summarized.     

Vortex Matter in Active and Passive Superconducting Devices

In this contribution it is demonstrated (i) that active as well as passive superconducting devices can be used as very sensitive tools for detecting motion and penetration of vortices in superconducting material and (ii) that the analysis of the distribution of vortices in the device can be used for optimization of these devices for application. The potential for applications of superconducting devices strongly depends upon the reduction of dissipative processes due to vortex motion. Whereas vortex motion in active devices leads among others to increased low-frequency noise and, thus, reduces the sensitivity of e.g. SQUIDS, vortices in microwave devices reduce the quality factor and, finally, the power handling capability. For both types of devices vortex penetration at extremely low magnetic induction can be observed and the position of penetrating vortices can be deduced by adequate analysis of the recorded magnetic flux or power handling property for SQUIDS or resonator, respectively. The effect of vortex penetration and trapping of flux-for instance by strategically positioned antidots-upon the performance of the device will be demonstrated and, finally, methods to reduce or avoid the negative impact of vortices in these devices are sketched.     

High-Density Er-Implanted GaN Optical Memory Devices

Upconversion emission has been obtained from Er-focused ion-beam (FIB) implanted GaN. Visible green emission at the 522- and 546-nm range were excited with infrared (IR) laser sources at either 840 or 1000 nm, or with both lasers simultaneously. By implanting closely spaced patterns with the FIB, we demonstrated the concept of storing data in Er-implanted GaN. Information stored as data bits consists of patterns of implanted locations as logic 1 and unimplanted locations as logic 0. The photon upconversion process in Er ions is utilized to read the stored information. This process makes use of the IR lasers to excite visible emission. The integrated upconversion emission power was measured to be ~40 pW when pumped by a 840-nm laser at 265 mW and by a 1000-nm laser at 208 mW. Patterns as small as 0.5 mum were implanted and read. Three-dimensional optical memory based on rare-earth-doped semiconductors could in theory approach a storage capacity of 10(12) bits/cm(3).     

无源器件在片散射参数校准比较方法研究

为解决由于不同校准方法导致无源器件在片散射参数测试结果存在偏差的问题,通过以校准准确度高的多线TRL校准方法为参考基准,比较SOLT、LRRM校准方法与其误差项的差异.充分考虑了两个端口误差项的级联关系,推导得到误差项差异的数学模型,通过参数转换计算得到无源器件在片散射参数的最大偏差.在100MHz～67GHz频段范围...     

Plasmonics—A Route to Nanoscale Optical Devices

The further integration of optical devices will require the fabrication of waveguides for electromagnetic energy below the diffraction limit of light. We investigate the possibility of using arrays of closely spaced metal nanoparticles for this purpose. Coupling between adjacent particles sets up coupled plasmon modes that give rise to coherent propagation of energy along the array. A point dipole analysis predicts group velocities of energy transport that exceed 0.1c along straight arrays and shows that energy transmission and switching through chain networks such as corners (see Figure) and tee structures is possible at high efficiencies. Radiation losses into the far field are expected to be negligible due to the near‐field nature of the coupling, and resistive heating leads to transmission losses of about 6 dB/μm for gold and silver particles. We analyze macroscopic analogues operating in the microwave regime consisting of closely spaced metal rods by experiments and full field electrodynamic simulations. The guiding structures show a high confinement of the electromagnetic energy and allow for highly variable geometries and switching. Also, we have fabricated gold nanoparticle arrays using electron beam lithography and atomic force microscopy manipulation. These plasmon waveguides and switches could be the smallest devices with optical functionality.     

Passive Detection of Motion Transverse to the Optical Viewing Axis

The passive detection of velocities of objects moving transverse to the optical viewing axis is discussed from the standpoint of the spatial Fourier transform of the image. A simple algorithm is developed which yields the velocity, as a function of time, of an object moving against a complicated background. This algorithm relies on monitoring magnitude and phase of two prominent spatial Fourier components. Measurement of the Fourier components is most simply accomplished with the direct electronic Fourier transform (DEFT) sensor. This device employs coupling between the image intensity, surface acoustic waves, and electron current in a CdS film to decompose the image into Fourier components. Experimental results show strong confirmation between theory and experiment. The paper concludes with a brief comparison of the DEFT implementation versus other systems in terms of speed, sensitivity, and cost.     

Sol-Gel-Based Integrated Optical Microring Resonator Humidity Sensor

A novel humidity sensor based on sol-gel clad polymer microring resonator is presented. This sensor is based on the principle of change in refractive index of sol-gel on exposure to moisture. This change causes a shift in the resonant wavelength of the microring resonator. The performance of this sensor is analyzed and different ways of tailoring the sensor response are suggested. This sensor has a sensitivity of 16 pm/% relative humidity (RH) and a dynamic range up to 72% RH. The response time of this sensor can be tailored to be less than 200 ms, which could be utilized for monitoring human breathing condition in medical applications.