Cost, performance, and reliability simulator for optical transceiver modules

The program couple combines simulators for optical performance, mechanical reliability, and production cost under a graphical-user interface to design, simulate, and evaluate micro-optomechanical structures. The thermal simulator predicts the package temperature distribution on the basis of the materials and the geometry as well as on heat sources, sinks, and boundary conditions. The thermal distribution is input to the mechanical simulator, which calculates the stresses or strains and displacements caused by differential thermal expansion. The optical simulator predicts the impact on the optical efficiency and the cross talk of mechanical and optical parameter variations such as solder heights, misalignments, and wavelength distributions. The cost simulator represents the manufacturing process flow and calculates the final cost and the cost sensitivity on basis of the cost and the yield of each process step. By means of balancing detector and coupling yield, cosimulation from optical to cost domains determines the optimum detector size to produce the lowest-cost transceiver module.     

2 Gbit/s 0.5 microm complementary metal-oxide semiconductor optical transceiver with event-driven dynamic power-on capability

A 2 Gb/s0.5 microm complementary metal-oxide semiconductor optical transceiver designed for board- or backplane level power-efficient interconnections is presented. The transceiver supports optical wake-on-link (OWL), an event-driven dynamic power-on technique. Depending on external events, the transceiver resides in either the active mode or the sleep mode and switches accordingly. The active-to-sleep transition shuts off the normal, gigabit link and turns on dedicated circuits to establish a low-power (approximately 1.8 mW), low data rate (less than 100 Mbits/s) link. In contrast the normal, gigabit link consumes over 100 mW. Similarly the sleep-to-active transition shuts off the low-power link and turns on the normal, gigabit link. The low-power link, sharing the same optical channel with the normal, gigabit link, is used to achieve transmitter/receiver pair power-on synchronization and greatly reduces the power consumption of the transceiver. A free-space optical platform was built to evaluate the transceiver performance. The experiment successfully demonstrated the event-driven dynamic power-on operation. To our knowledge, this is the first time a dynamic power-on scheme has been implemented for optical interconnects. The areas of the circuits that implement the low-power link are approximately one-tenth of the areas of the gigabit link circuits.     

LTC1387多通信标准发送接收器芯片及应用

本文介绍LinearTechnology公司的 5V单电源RS2 3 2 /RS485多通信标准发送接收器芯片LTC13 87的主要特性 ,各引脚功能 ,应用方法及几个主要的应用实例。     

A near-field-sensing transceiver for intrabody communication based on the electrooptic effect

This paper describes a near-field-sensing transceiver for intrabody communication, in which the human body is the transmission medium. The key component of the transceiver is an electric-field sensor implemented with an electrooptic crystal and laser light. This sensor is suitable for detection of the small and unstable electric fields produced by the human body because it has extremely high input impedance. This transceiver enables IEEE 802.3 half-duplex communication of 10 Mb/s through a person's body in an operating range of about 150 cm between the hands. The packet error rate of 0.04% is obtained at packet size of 1070 octet. This paper explains the configuration and performance of the transceiver and presents results of a communication test.     

Bidirectional optical coupler for plastic optical fibers

We have developed a low-loss bidirectional optical coupler for high-speed optical communication with plastic optical fibers (POFs). The coupler, which is fabricated by an injection molding method that uses poly (methyl methacrylate), has an antisymmetric tapered shape. We show that the coupler has low insertion and branching losses. The tapered shape of the receiving branch reduces beam diameter and increases detection efficiency coupling to a photodetector, whose area is smaller than that of the plastic optical fiber. The possibility of more than 15-m bidirectional transmission with a signaling bit rate up to 500 Mbits/s for simplex step-index POFs is demonstrated.     

A few-mode optical fiber retaining optical vortices

The ability of an optical fiber with axial losses to selectively suppress the fundamental HE ₁₁ mode, as well as the TE and TM waveguide modes, and, simultaneously, to transmit optical vortices with almost zero energy losses is considered. The attenuation coefficients for the corresponding eigenmodes and vortices are determined. It is shown that such a fiber operates as a mode filter for the feeding beam.     

Multi-wavelength optical pickup with diffractive optical elements

Abstract

A novel, to our knowledge, multi-wavelength diffractive optical pickup is presented. The pickup enables multi-focus imaging and increases the data transfer rate considerably. Parallel reading of two or more memory layers is possible. The different spots can be controlled independently. The optical pickup consists of different diffractive optical elements (DOEs). The measured full-width at half-maximum (FWHM) spot intensity for the DOE-pickup is 0.76 μm—close to the diffraction limited predicted value of 0.71 μm—indicating good optical performance. The measured highest diffraction efficiencies of the realized DOEs are about 92%.     

Nonlinear optical beam propagation for optical limiting

We implement numerical modeling of high-energy laser-pulse propagation through bulk nonlinear optical materials using focused beams. An executable program with a graphical user interface is made available to researchers for modeling the propagation of beams through materials much thicker than the diffraction length (up to 10(3) times longer). Ultrafast nonlinearities of the bound-electronic Kerr effect and two-photon absorption as well as time-dependent excited-state and thermal nonlinearities are taken into account. The hydrodynamic equations describing the rarefaction of the medium that is due to heating are solved to determine thermal index changes for nanosecond laser pulses. We also show how this effect can be simplified in some cases by an approximation that assumes instantaneous expansion (so-called thermal lensing approximation). Comparisons of numerical results with several Z-scan, optical limiting and beam distortion experiments are presented. Possible application to optimization of a passive optical limiter design is discussed.     

Random optical codes used in optical networks

An analysis of a simple way to design generalised optical orthogonal codes to be used in optical code-division multiple-access systems is presented. They are random optical codes (ROCs). This novel family is especially suitable for optical networks with a large number of channels, low bit rate requirements, energy limitations and packed data. For example, sensor networks need these requirements. An application in an intra-spacecraft telecommand and telemeasurement (TC/TM) optical wireless network is also described. ROCs are selected randomly from all possible rearrangements. However, its probability of error is adequate in many useful parameter ranges. Moreover, ROCs present features not found in other families of codes such as huge cardinality and parameter adaptation to the system necessities. Here, the main contribution is to present a method to optimise the values of the parameters. Furthermore, the optimal weight of the codes is found, given two out of the other set of parameters, that is, the length, the number of users and the probability of error. In addition, a comparison between the length and the power consumption of ROCs and prime codes is also developed.     

基于离散傅立叶变换扩频的广义多载波系统收发机频域简化实现方法

针对基于离散傅立叶变换扩频的广义多载波(DFT-S-GMC)系统的收发机时域实现方法复杂度较高的问题,提出了一种频域等效收发机实现方法;利用滤波器组各子带频率响应能量比原型滤波器的时域冲击响应能量集中的特性,提出了一种基于该频域实现方法的收发机简化实现方法和结构.仿真和分析表明,在多径信道下,采用频域简化实现结构的收发机与现有基于时域实现结构的收发机的误码率(BER)性能几乎相同,但与现有时域实现方法相比,采用频域简化实现方法,DFT-S-GMC系统发射机的实现复杂度可显著降低.     

Polymer optical fibers and nonlinear optical device principles

Basic principles of the present optoelectronic research activities at Hoechst AG are presented in this contribution. Within the diversified broad band spectrum of optoelectronic materials and applications our interest is focused on new types of polymer optical fibers and nonlinear optical device principles using organic Langmuir–Blodgett films and electrically poled polymers. The basic principles and the limits of the present research and development activities which, have a high market potential are outlined.     

Integrated optoelectronics for optical interconnections and optical processing

Integrated optoelectronics using III–V compound semiconductor technology has so far shown exciting advances for application in optical telecommunication systems. New applications of this technology are in optical interconnections and signal processing systems. The technology is expected to be very effective in solving the wiring limit in data transmission within electronic systems, using the advantages of optical techniques such as high data transmission rate and high parallelism, and thus improve the performance of overall systems. Optical interconnection devices currently being developed aim both at multiplexing vast amounts of data and exhibiting flexible interconnection functions using the advantageous characteristics of light. Future research is expected to explore new techniques such as that for multiplexing and processing data in the wavelength division as well as for integrating functional devices in two-dimensions. Synergetic collaboration among materials and processing, design and fabrication, and packaging areas is extremely important and this will lead to practical optical interconnections and signal processing systems.     

Programmable optical logic systems using free-space optical interconnections

A free-space optical logic technique is presented that utilizes a two-dimensional array of diffractive optical elements. Each optical element focuses light to multiple, separate positions in the output focal plane. The focal spots from different optical elements are allowed to overlap spatially, resulting in interference. By changing the phase shift between the optical elements, one can create different optical logic operations in the focal plane. The technique is demonstrated by the use of two input beams incident onto a multiplexed optical element written onto a programmable spatial light modulator. The optical element simultaneously creates both AND and XOR logic functions in the output plane.     

Self-alignment with optical microconnectors for free-space optical interconnections

A self-alignment technique that uses optical microconnectors forthree-dimensional optics in optical computing systems and opticalinterconnections is proposed. The optical microconnector consistsof an optical plug and a socket. On the output plane of an opticalsystem, optical plugs are made of a photosensitive resin exposed tolight through the optical system. Because the correspondingpositions of the optical plugs are critical to the image formed by theoptical system, a detecting device can be aligned and mounted by theconnection of the optical plugs to sockets formed on the surface of thedevice. Optical microconnectors were experimentally fabricated in areflective block optical system. An alignment accuracy of ~20 mum was attained in the experiment.     

光学材料和光学薄膜的光热表征(英文)

光热技术用来测量样品的光学和热特性。简要介绍了光热技术及其在光学薄膜测量和钛蓝宝石激光晶体表征中的应用。光热技术可以提供纯光学光谱学所无法提供的、类似光-热能量转换效率之类的信息。光热技术已被用作质量测试和改善现代光学制造的有用工具。     

Laser optical feedback imaging insensitive to parasitic optical feedback

We present an optical architecture for the laser optical feedback imaging (LOFI) technique that makes it possible to avoid the effect of the optical parasitic reflections introduced by the optical components located between the laser source and the studied object. These reflections damage phase and amplitude information contained in the images. This phenomenon is a leading problem that strongly limits the LOFI performance for weak feedback detection. Consequently, it is essential to be able to limit or avoid the effect of these parasitic reflections to reach the optimal LOFI performance.     

Amplified double-coupler double-ring optical resonators with negative optical gain

Optical resonators with a double-coupler and double-ring configuration incorporated into optical amplifiers that have negative gain are analyzed. The resonators are presented with a unique signal-flow graph together with z-transform variables for sampled optical signals. Their optical transfer functions are obtained by a graphical technique. The poles and zeroes in the z plane of the transfer functions are examined, which leads to some unique design features of the resonators for optical-filtering applications.     

Planar antiresonant reflecting optical waveguides as integrated optical refractometer

This paper reports on an integrated refractometer sensor, useful for measuring chemical quantities, based on antiresonant reflecting optical waveguides (ARROWs). We show that, by a suitable design, the attenuation in ARROW waveguides can strongly depend on the refractive index of the superstrate layer. We use this property to design and realize an integrated refractometer. The proposed sensor structure is unique in that it consists in the ARROW waveguide itself acting like a vertical interferometer. The device is fabricated using standard silicon technology fully compatible with bipolar and CMOS integrated circuit process. The measurement results show a sensing resolution of /spl Delta/n = 6e - 4 when used in a solution with a refractive index of 1.4600.