Two-dimensional optoelectronic devices for future optical switching and information processing

Recent progress is reviewed in surface-normal optoelectronic devices primarily for use in optical switching and information processing. A type of optoelectronic integrated circuit (OEIC), the surface-normal two-dimensional array, is fabricated using these devices. This improves on first-generation OEICs by featuring large-scale integration in a small area, which results in a higher production yield. It also has structures which can easily be integrated with electronic circuits and can meet multichannel requirements. This approach supports optoelectronic progress towards optical information processing.     

Measurements of return loss on OEIC structures,using optical low-coherence reflectometry

Optical low-coherence reflectometry (OLCR) has been applied for the first time to the ovaluation of optoelectronic integrated circuits (OEICs). Benefits are demonstrated for analysis and measurement of integrated structures. In particular reflection strengths of various integrated devices and interfaces on real fibred OEICs have been quantified.     

可调谐超构透镜的发展现状

随着新兴光学设备对微型化、一体化、智能化光学变焦系统的需求与日俱增,大大促进了纳米光电子学的迅猛发展。超构透镜是由具有特殊电磁属性的人造元素按照一定的排列方式组成的具有透镜功能的二维平面结构,其最大优点就是:轻薄和易于集成。然而,集成在超构透镜上的微纳结构一旦制备完成,便难以再改变其形貌或者尺寸,因而无法对其聚焦性能进行实时调控,限制了其功能及应用范围的进一步扩展。近年来,科学家们探索了实现超构透镜聚焦性能实时调控的多种途径,其中最引人注目的是将智能材料与超构透镜相结合。本文首先回顾了可调谐超构透镜的最新进展,分别详细阐述和分析了它们的调节原理和器件性能。最后,归纳分析了当前阻碍可调谐超构透镜发展的主要问题,并进一步对未来可调谐超构透镜的发展趋势做出了展望。     

Opto-electronic integrated circuits using the InGaAsP/InP system

Recent developments in opto-electronic integrated circuits (OEICs) using the InGaAsP/InP system which is monolithically integrated with opto-electronic and electronic devices are discussed. The technological problems for the development of the OEICs are explained by reviewing recent developments in OEICs.     

人工表面等离激元超材料

以微带为代表的传统微波传输线无法精细操控电磁模式,因此传统电子信息系统在空间耦合、动态响应和性能鲁棒性等方面存在瓶颈.人工表面等离激元(SSPP)超材料可打破上述瓶颈,是光学与信息领域的研究热点之一.人工表面等离激元超材料是一类模拟光频段表面等离激元特性的新型超材料,可在微波和太赫兹频段精细操控表面波,具有与平面电路相...     

OEIC technologies for high-speed optical interconnection system

As the level of integration and the power of computation increase, methods of interconnecting computational elements attract more attention and the total system performance is bottlenecked by the problems associated with electrical interconnections. Optical interconnections have advantages of practically unlimited bandwidth and absence of crosstalk. To utilize such merits of optical interconnections, a large number of low-cost high-performance optoelectronic integrated circuits (OEICs) are needed. This paper focuses on monolithically integrated receiver OEICs that consist of InP/InGaAs p-i-n photodiodes and fully ion-implanted InP junction field-effect transistors (JFETs). In the formation of shallow InP p-n junctions we use a co-implantation technique in which we implant a group V element together with Be, a dopant, and take advantage of damage and stoichiometry effects. We fabricate a p-i-n/JFET amplifier receiver front-end circuit and a receiver 2×2 crosspoint switch circuit using this technique. We also develop bandwidth enhancement designs using inductive peaking and cascoding. Finally, we demonstrate a single-channel, free-space optical interconnection system with a bandwidth of 1.5 GHz and an interconnection length of 50 cm.     

太赫兹数字全息术的研究进展

随着太赫兹成像技术的不断成熟,其空间分辨率和系统信噪比逐渐提高,成像速度逐渐加快,光学信息获取能力逐渐变强,人们对太赫兹成像在基础研究和工业应用的开发也逐渐深入。本文综述了近年来科研人员利用太赫兹数字全息成像系统进行的部分研究工作,包括对平板太赫兹元件的性能表征、对光控太赫兹元件的功能验证、对衍射太赫兹场中的纵向分量进行观测、以及对金属亚波长器件的太赫兹表面波进行分析。这些工作的完成对于太赫兹集成系统的研究和太赫兹成像技术的应用都具有积极的推动作用。     

Analytical approximation solutions for 3-D optical waveguides: Review

The rectangular dielectric waveguide is the most commonly used structure in integrated optics, especially in semi-conductor diode lasers. Demands for new applications such as high-speed data backplanes in integrated electronics, waveguide filters, optical multiplexers and optical switches are driving technology toward better materials and processing techniques for planar waveguide structures. The infinite slab and circular waveguides that we know are not practical for use on a substrate because the slab waveguide has no lateral confinement and the circular fiber is not compatible with the planar processing technology being used to make planar structures. The rectangular waveguide is the natural structure. In this review, we have discussed several analytical methods for analyzing the mode structure of rectangular structures, beginning with a wave analysis based on the pioneering work of Marcatili. We study three basic techniques with examples to compare their performance levels. These are the analytical approach developed by Marcatili, the perturbation techniques, which improve on the analytical solutions and the effective index method with examples. T Srinivas received the B.Sc. (Hon.) degree from Nehru Science College, Hydrabad and M.E. (Int.) and Ph.D. dgrees from the Indian Institute of Science, Bangalore, India. He was a Postdoctoral Research Fellow at Toyohashi University of Technology, Japan from 1992 to 1996. He is currently an Associate Professor with the Department of Electrical Communication Engineering, Indian Institute of Science. His areas of interests are optical communication networks, integrated optics, micro-opto-electrical-mechanical systems (MOEMS) and fiberoptic sensors     

Electro-Optic Polymer Integrated Optic Devices and Future Applications

Recent developments in electro-optic polymer materials and devices have led to new opportunities for integrated optic devices in numerous applications. The results of numerous tests have indicated that polymer materials have many properties that are suitable for use in high-speed communications systems, various sensor systems, and space applications. These results, coupled with recent advances in device and material technology, will allow very large bandwidth modulators and switches with low drive voltages, improved loss, long-term stability, and integration with other microelectronic devices such as MEMS. Low drive voltage devices are very important for space applications where power consumption scales as the square of the modulator half-wave voltage. In addition, we have demonstrated novel dual polymer modulators for mixing RF signals to produce sum and difference frequency modulation on an optical beam. This novel approach allows the suppression of the modulation at the two input RF signals, and only the mixing signals remain superposed on the optical beam. The dual modulator can be used for various encoding/decoding and frequency conversion schemes that are frequently used for both terrestrial and space communications. Another application of polymer integrated optics is in the field of optical sensing for high-frequency (GHz) electric fields.     

Electro-Optic Polymer Integrated Optic Devices and Future Applications

Recent developments in electro-optic polymer materials and devices have led to new opportunities for integrated optic devices in numerous applications. The results of numerous tests have indicated that polymer materials have many properties that are suitable for use in high-speed communications systems, various sensor systems, and space applications. These results, coupled with recent advances in device and material technology, will allow very large bandwidth modulators and switches with low drive voltages, improved loss, long-term stability, and integration with other microelectronic devices such as MEMS. Low drive voltage devices are very important for space applications where power consumption scales as the square of the modulator half-wave voltage. In addition, we have demonstrated novel dual polymer modulators for mixing RF signals to produce sum and difference frequency modulation on an optical beam. This novel approach allows the suppression of the modulation at the two input RF signals, and only the mixing signals remain superposed on the optical beam. The dual modulator can be used for various encoding/decoding and frequency conversion schemes that are frequently used for both terrestrial and space communications. Another application of polymer integrated optics is in the field of optical sensing for high-frequency (GHz) electric fields.     

Organic materials in future integrated optoelectronic circuits

During the last two decades, lithium niobate has been extensively studied for applications in integrated optical circuits. However, it is difficult to integrate lithium niobate optical devices with semiconductor electronic devices because the materials are incompatible. In recent years, semiconductor materials have been emerging as the main contenders in applications; these materials have the advantage of allowing both optical and electronic devices to be integrated. Further, the semiconductor technology has advanced rapidly, allowing us to engineer device parameters very precisely. In semiconductor optoelectronic devices, that is, bulk and quantum well structures, electroabsorption has mainly been used for amplitude modulation of light. The electrorefraction effect is the most useful for devices employing phase-modulation techniques, but this effect cannot be effectively utilized in semiconductors since the strongest electrorefraction effect is near the absorption edge of the material. Recently, organic materials have been shown to have electro-optic coefficients equal to or larger than that of lithium niobate. There are major advantages of organic materials: (1) the organics can be deposited on semiconductor substrates, and therefore both electronic and optical circuits can be integrated; (2) in organic materials the electrorefraction can be effectively utilized to obtain both amplitude and phase modulation; (3) the organic material composition can be adjusted to satisfy some device requirements. In this paper, a comparison of these material systems are made in terms of device applications.     

BOR-FDTD analysis of nonlinear Fiber Bragg grating and distributed Bragg resonator

Recently, nonlinear materials have attracted a great deal of attention because of their importance in designing new devices to meet a need range of optical systems. An intense investigation of the possibility of using these materials for all optical ultrafast applications is achieved by allowing their dielectric characteristics to be varied in such a way that a periodic perturbation of their refractive index along the length of the waveguide will be formed. The Finite-Difference Time-Domain (FDTD) method, on the other hand, has been proven to be one of the most powerful numerical techniques that are usefully applied to a wide range of optical devices. In this paper, a FDTD technique, developed for nonlinear structures, is used to analyze a nonlinear waveguide and periodic nonlinear structures that exhibit attractive properties that make them suitable for novel devices with wavelength tunable characteristics. More specifically, the Bodies of Revolution (BOR) FDTD numerical simulation method will be used to model the fiber Bragg Grating (FBG) and the direct integration method will be employed to include the effect of Self Phase Modulation (SPM) in this model. The combination of these techniques will result in a model that is used to analyze two different types of periodic nonlinear structure, FBG and Distributed Bragg Resonator (DBR). The nonlinear effect provides the designer an added degree of design flexibility for devices with wavelength tunable characteristics, for example, in the design of tunable filters, WDM systems and optical sensors.     

基于倏逝场耦合的石墨烯波导光传输相位特性仿真与实验研究

石墨烯材料应用到各种光波导器件中正成为新一代光子器件的重要发展方向之一,目前基于石墨烯的光纤和集成光子器件研究越来越受到国内外的重视. 本文建立了一种由微纳光纤耦合光倏逝场,并在石墨烯薄膜中传输的模型. 通过有限元分析法,研究了光在这种石墨烯波导中传输光场的强度分布和相位特性,并通过实验进行了验证. 结果表明,沿着微纳光纤-石墨烯光波导传播的倏逝场的强度分布和相位均受石墨烯材料作用,石墨烯材料能有效聚集和导行波导中传输的高阶模,在单位传输长度上具有更密集的等相位面. 本文提出了一种利用微纳光纤耦合光倏逝场研究石墨烯相位响应特性的新方法,对基于石墨烯波导的新型调制器、滤波器、激光器和传感器等光子器件的设计和应用具有一定的参考意义. 关键词： 石墨烯平面光波导 倏逝波 光场强度 相位     

Turning the world vertical: MOSFETs with current flow perpendicular to the wafer surface

Tremendous progress in information technology has been made possible by the development and optimization of metal oxide semiconductor field effect transistor (MOSFET) devices. For the last three decades, the dimensions of the devices have been scaled down and the complexity of the integrated circuits increased according to Moore’s law. Further scaling of the devices has been predicted by the international technology roadmap for semiconductors (ITRS). To meet the future technological requirements, much effort has been expended on increasing the capabilities of MOSFETs. Both new materials and new designs have been introduced to maintain device scaling. Most new designs were improvements of the normal planar design of the device, such as SOI and ultrathin body devices. In so-called FinFET structures, current flows through a thin silicon fin and is controlled by two gates in parallel on both sides of the fin. Vertical MOSFET devices represent a new category. In these structures the planar arrangement of the source gate and drain is turned through 90° so that they are positioned on top of each other and the current flow is perpendicular to the surface. By utilizing the 3rd dimension, the channel length can be adjusted by layer deposition and thus dispensing with advanced (and expensive) lithography. Furthermore, depending on the application, the vertical designs require less space than planar ones so that it is possible to increase integration density. The present paper gives a review of vertical MOSFET devices with current flow perpendicular to the surface. PACS 85.30     

OEIC research in Korea

This paper presents a chronological overview of Korean activities in optoelectronics and optoelectronic integrated circuits (OEICs) undertaken mainly in university laboratories. OEIC transmitters and receivers for communications and semiconductor laser logic devices for optical switching and computing are briefly described.     

Advances in Functional Nanomaterials Science

Technologies employing nanomaterials, such as electronics, optoelectronics, nanobiotechnologies, quantum optics, and nanophotonics, are perceived as the key drivers of investigations on novel and functional materials and their nanostructures for various applications. It is well understood that the study of such materials and structures has been of great importance for the optimization and development of electrical and optical devices. From such devices, one does not only expect higher efficiencies, but also access to the development of completely new concepts, which are strongly demanded by modern information-processing, quantum, or medical technologies, and sensing applications. In this context, a wide range of aspects such as the physics of novel materials, as well as materials engineering, characterization, and applications are summarized here. Novel materials, which can be used, for instance, for energy harvesting or light generation, as well as for future logic devices; material engineering, which can lead to improved device functionality and performance in optoelectronics; material physics, the study of which allows insight to be gained into optical and electrical properties of nanostructured systems and quantum materials; and technologies/devices, addressing progress on the application side of sophisticated material systems and quantum structures, are highlighted using representative examples.     

Realization of simultaneous balanced multi-outputs for multi-protocols QKD decoding based onsilica-based planar lightwave circuit

Silica-based planar lightwave circuit (PLC) devices can reduce transmission loss and cost in a quantum key distribution (QKD) system, and have potential applications in integration and production. A PLC-based quantum decoding integrated chip for multi-protocols is designed and fabricated, which is composed of variable optical splitters (VOSs), asymmetric Mach-Zehnder interferometers (AMZIs), and variable directional couplers (VDCs). Balanced pulse-pairs of four outputs are obtained simultaneously with measured delay times of 405 ps and 402 ps, respectively. The chip has advantages in achieving high interference visibility and low quantum bit error rate (QBER).     

光学超振荡与超振荡光学器件

传统光学器件的衍射极限极大地制约了远场超分辨光学系统的进一步发展.如何从光学器件层面突破光学衍射极限瓶颈,实现非标记远场超分辨光学成像,是光学领域面临的巨大挑战.光学超振荡在不依靠倏逝波的条件下,可以在远场实现任意小的亚波长光场结构,这为突破光学衍射极限提供了一条崭新的途径.近年来,光学超振荡现象和超振荡光学器件的相关研究得到了快速发展,在理论和实验上成功地演示了超振荡光场的产生和多种超振荡光学器件,并在实验上展示了超振荡光学器件在非标记远场超分辨光学显微、成像以及超高密度数据存储等应用领域的巨大优势和应用潜力.本文对光学超振荡相关理论、超振荡光学器件设计理论和方法、超振荡光学器件发展现状、超振荡光场测试方法以及超振荡光学器件的应用等方面进行详细介绍和分析.     

半导体微结构物理效应及其应用讲座第三讲半导体的激子效应及其在光电子器件中的应用

人们对半导体中的电子空穴对在库仑互作用下形成的激子态及其有关的物理性质进行了深入研究.激子效应对半导体中的光吸收、发光、激射和光学非线性作用等物理过程具有重要影响,并在半导体光电子器件的研究和开发中得到了重要的应用.与半导体体材料相比,在量子化的低维电子结构中,激子的束缚能要大得多,激子效应增强,而且在较高温度或在电场作用下更稳定.这对制作利用激子效应的光电子器件非常有利.近年来量子阱、量子点等低维结构研究获得飞速的进展,已大大促进了激子效应在新型半导体光源和半导体非线性光电子器件领域的应用.     

Atomic spectroscopy and quantum optics in hollow‐core waveguides

Atomic spectroscopy is a well‐established, integral part of the physicist's toolbox with an extremely broad range of applications ranging from astronomy to single atom quantum optics. While highly desirable, miniaturization of atomic spectroscopy techniques on the chip scale was hampered by the apparent incompatibility of conventional solid‐state integrated optics and gaseous media. Here, the state of the art of atomic spectroscopy in hollow‐core optical waveguides is reviewed The two main approaches to confining light in low index atomic vapors are described: hollow‐core photonic crystal fiber (HC‐PCF) and planar antiresonant reflecting optical waveguides (ARROWs). Waveguide design, fabrication, and characterization are reviewed along with the current performance as compact atomic spectroscopy devices. The article specifically focuses on the realization of quantum interference effects in alkali atoms which may enable radically new optical devices based on low‐level nonlinear interactions on the single photon level for frequency standards and quantum communication systems.