Polymer waveguide with integrated reflector mirrors for an inter-chip link system

A polymer waveguide with integrated reflector mirrors is presented for an inter-chip link system. The cost-effective and repeatable technology for the integration of a polymer multimode waveguide and out-of-plane 45° reflector mirrors was developed for optical coupling between the light-sources and the light-detectors. This method enabled us to fabricate the waveguides and 45° reflector mirrors using a one-shot embossing process for inexpensive mass production. The optical inter-chip link system consisted of a metal optical bench, a module printed circuit board (PCB), a driver/receiver IC, a vertical-cavity surface-emitting laser (VCSEL)/photo-detector (PD) array, and an optical waveguide composed of integrated reflector mirrors. The presented data transfer measurements of the optical inter-chip link system are shown to be successful at a data rate of 5 Gb/s.     

Efficient coupler between chip-level and board-level optical waveguides

We propose an efficient optical coupler between a submicrometer-sized silicon waveguide on a silicon photonic chip and a multi-micrometer wide polymer waveguide on an optical printed circuit board for interchip optical networks. We show low coupling loss <0.4 dB with high lateral and angular tolerance to misalignment so that coupling can be done by automatic pick-and-place equipments with high throughput and low cost. The coupler has a wide optical bandwidth from 1470 to 1650 nm.     

Three-dimensional global interconnect based on a design window

Based on a stochastic wire length distributed model, the interconnect distribution of a three-dimensional integrated circuit (3D IC) is predicted exactly. Using the results of this model, a global interconnect design window for a giga-scale system-on-chip (SOC) is established by evaluating the constraints of 1) wiring resource, 2) wiring bandwidth, and 3) wiring noise. In comparison to a two-dimensional integrated circuit (2D IC) in a 130-nm and 45-nm technology node, the design window expands for a 3D IC to improve the design reliability and system performance, further supporting 3D IC application in future integrated circuit design.     

Low-distortion hybrid optical shuffle concept

A hybrid micro-macro-optical shuffle interconnection approach is described. The new concept minimizes distortion in multichip smart-pixel shuffle interconnection systems that use macro-optics to link dense arrays of vertical-cavity surface-emitting laser (VCSEL) sources and matching arrays of detectors. The typical narrow-beam cones of VCSEL's are exploited by use of beam-deflecting micro-optics to create an optical system that is symmetric about its aperture. Since symmetric systems are well known to cancel distortion, this novel concept provides the means to achieve the required high degree of interchip registration accuracy.     

Optical interconnects: the challenge

As the integrated circuit complexity and speed increase, interconnects become the main bottleneck in microelectronics processes for further improvements of the performances. Optics is considered as a possible alternative solution to meet the expected requirements, and has already proven its advantages for distances which progressively shorten from optical telecommunications towards inter-boards, and then interchip connections. This paper focuses on the potentialities of optical solutions for intrachip interconnects.     

交调失真影响下星间微波光子链路接收灵敏度优化

高输入信号功率时的交调失真是降低星间微波光子链路接收灵敏度的主要因素。考虑输入N路四相相移键控(QPSK)调制信号的情形,建立了强度调制/直接检测(IM/DD)星间微波光子链路模型。利用傅里叶级数展开、傅里叶变换/逆傅里叶变换和Graf加法定理,推导出了接收信号任意谐波和交调分量的解析表达式,在确定三阶交调失真个数的基础上,得到了接收光功率与信号噪声失真比(SNDR)之间的关系。着重分析了不同调制方式下链路接收灵敏度与信道数和调制系数之间的关系。当调制系数较小时,接收灵敏度对信道数变化不敏感。随着调制系数的增大,接收灵敏度先增大后减小,存在最佳的调制系数可以使链路接收灵敏度最高。     

Optical performance models for FDDI links

A loss budget model has been developed to predict optical perjormnce of the fiber distributed-data interjace (FDDI) type of networks in the premises-distribution environment. This model tailors existing statistical loss budget models to the FDDI standard. It is expected that as FDDI becomes popular, fiber-based distribution systems will become common. When designing a fiber-distribution system, it is important to understand the constraints placed on link perjormance by the cable plant. To determine these constraints, the model is examined numerically using a large range of initial conditions. The total link length is used as the dependent variable. This set of initial conditions corresponds to an ensemble ofpossible link configurations, and these link configurations are studied in the context of the premises-distribution environment.

The model is extended to include the use of optical bypass switches. Laboratory measurement data are presented to verify the accuracy of the bypass switch model. The extended model, including the bypass switch, is examined numerically for a similar set of initial conditions. These constraints are applied to the use of bypass switches in wiring closets, between Jlaors, and at the work location. Distance limitations are determined for FDDI links utilizing optical bypass switches.     

模块化固体开关脉冲功率源触发技术

为满足高功率脉冲源小型化和高重复频率运行的研制需要,提出了一种基于固体开关(可控硅)的电感隔离型高压脉冲发生器触发控制设计方案。这种方案采用光纤收发器件及其驱动电路和高耐压脉冲变压器,研究了固体开关脉冲功率源控制技术中的触发信号高压隔离、光分多路及脉冲变压器分立或并联使用等关键技术。给出了单模块触发控制电路的设计及测试结果:5级LC回路在每级充电电压4 kV输入时,实现最终32 kV的输出,功率源模块输出/输入电压转换效率达到80%。同时对其应用特点进行了分析和讨论。     

Integrated optical fiber data link transmitter/receiver for local area network application

Optical fiber data link transmitters and receivers have been developed for local area network applications. The features are of wide-bit-rate range and wide dynamic range as well as compact and of highly reliable construction. State-of-the-art LSI technology has been applied for the circuit electronics integration. Design emphasis was also placed on the optical connector development for ease of operation as well as reliable connection and compact size.

The data link transmitter and receiver developed utilize an AlGaAs light-emitting diode and a Si PIN photodiode as the light source and detector, respectively. Performance data were obtained for a bit rate range of dc to 35 Mbps and an 18-dB dynamic range.     

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.     

大视场激光接收机设计

 介绍激光指令制导和激光驾束制导的大视场激光接收机的设计原理,给出接收光场的数学模型,由斜入射平行光的衍射光场推出探测光学系统的视场角公式,根据1064nm大视场激光接收机技术要求,以聚光物镜型探测光学系统为例,探讨接收光学系统既须具备特大相对孔径,又须具备无晕接收性能的设计特点,采用窄带干涉滤光镜进行光学滤波降噪。给出一种适用于高重频(200kHz)工作的低噪声放大器的设计实例,介绍了低噪声放大电路的设计原理。测试结果表明：设计的大视场激光接收机的接收视场角≥±10°,、动态范围≥40dB,当放大器输出信号信噪比等于4时接收灵敏度Pmin=5.38×105W。     

Highly reliable optical interconnection network on printed circuit board for distributed computer systems

A highly reliable interchip optical interconnection network on a printed circuit board (PCB) was designed and realized, and experiments confirmed that the data rate in each channel could reach above 3.125 Gbps and the bit error rate (BER) could be up to 1.27×10⁻¹⁸, which would be a good solution to the problem of communication bottlenecks between high-speed VLSI chips.     

160 km all-optical OFDM transmission system with inline chromatic dispersion compensation

An experimental demonstration of an all-optical sampling orthogonal frequency division multiplexing (AOS-OFDM) transmission system with inline chromatic dispersion (CD) compensation is carried out to test the nonlinear influence. With five subcarriers non-return-to-zero (NRZ) modulated, the total bit rate is 50 Gb/s without polarization multiplexing. The receiver end is highly simplified with direct detection using optical Fourier transform filter. After transmission in 160-km standard single-mode fiber (SSMF) link with 130-ps/nm residual CD, an optimum input optical power for the system performance is achieved.     

Effective simulation method for parametric signal-noise interaction in transmission fibers

We propose a new method for effective numerical simulation of transmission system performance and study of correlated noise evolution along an optical fiber with nonlinear parametric interaction between the amplified spontaneous emission (ASE) and the modulated optical signal. The method is based on an evaluation of the noise covariance matrix by using full nonlinear Schr?dinger equation (NLSE) and an analytical model for the optical receiver. Using extensive brute-force Monte Carlo simulation as a verification tool, we test the accuracy of the method and illustrate the analytical receiver model limitations in the case of moderate as well as substantial growth of non-Gaussian optical noise along the optical fiber transmission link.     

Reflection assisted beam propagation model for obstructed line-of-sight FSO links

A non-line-of-sight (NLOS) infra-red reflection based beam propagation model is proposed as a supplement to conventional terrestrial free space optical (FSO) communication system. This ray propagation model lets tactically positioned optical reflectors to smartly exploit the aggregated advantages of mirror characteristics to bridge the existent communication gap between two FSO nodes due to inclined or obstructed line-of-sight view. Additionally, a numerical framework of the proposed system is presented that analytically explores the optical losses induced by harmonic distortions and the resultant beam divergence at the receiver. The impact of the different reflectors on the traversing beam is then investigated through an experimental FSO test-bed set in an outdoor environment in terms of phase shifts, divergence loss, noise margin and maximum achievable link length. Matlab based simulations, based on the experimental outcomes, envisages that concave reflectors can effectively compensate the turbulence induced signal fading and restrict the beam divergence loss; thereby, improving the maximum achievable NLOS FSO link length.     

Monitoring long distance WDM communication lines using a high-loss loopback supervisory system

In this paper, we present experimental results for monitoring long distance WDM communication links using a line monitoring system suitable for legacy optically amplified long-haul undersea systems. This monitoring system is based on setting up a simple, passive, low cost high-loss optical loopback circuit at each repeater that provides a connection between the existing anti-directional undersea fibres, and can be used to define fault location. Fault location is achieved by transmitting a short pulse supervisory signal along with the WDM data signals where a portion of the overall signal is attenuated and returned to the transmit terminal by the loopback circuit. A special receiver is used at the terminal to extract the weakly returned supervisory signal where each supervisory signal is received at different times corresponding to different optical repeaters. Therefore, the degradation in any repeater appears on its corresponding supervisory signal level. We use a recirculating loop to simulate a 4600 km fibre link, on which a high-loss loopback supervisory system is implemented. Successful monitoring is accomplished through the production of an appropriate supervisory signal at the terminal that is detected and identified in a satisfactory time period after passing through up to 45 dB attenuation in the loopback circuit.     

Analysis of inter-satellite free-space optical link performance considering different system parameters

The welcome and adaptation of optical wireless technology by the modern era has brought forward the concept of an inter-satellite free-space optical communication system. In the present work, I study the combined effect of selection of different operating wavelengths and detector types along with the pointing errors at the transmitter and receiver side on the performance of an inter-satellite free-space optical link. The link performance has been optimized by measuring and analyzing the bit error rate and quality-factor of received signal under different scenarios. Performance of the inter-satellite link has also been investigated considering different modulation formats and data rates for LEO and MEO distances.     

Integrated optical fiber data link transmitter/receiver for local area network application

Optical fiber data link transmitters and receivers have been developed for local area network applications. The features are of wide-bit-rate range and wide dynamic range as well as compact and of highly reliable construction. State-of-the-art LSI technology has been applied for the circuit electronics integration. Design emphasis was also placed on the optical connector development for ease of operation as well as reliable connection and compact size.

The data link transmitter and receiver developed utilize an AlGaAs light-emitting diode and a Si PIN photodiode as the light source and detector, respectively. Performance data were obtained for a bit rate range of dc to 35 Mbps and an 18–dB dynamic range.     

Performance improvement and wavelength reuse in millimeter-wave radio-over-fiber links incorporating all-fiber optical interleaver

Simultaneous downlink performance improvement and uplink wavelength reuse in a full-duplex millimeter-wave (MMW) radio-over-fiber (RoF) system by using a simple and cost-effective all-fiber optical interleaver are proposed and demonstrated. The MMW RoF downlink performance improvement is based on suppressing optical carrier-to-sideband ratio (OCSR), with which the mechanism is confirmed by theoretic analysis and derived experimental results. Measured results show that, by suppressing OCSR using a fabricated all-fiber optical interleaver, the downlink optical receiver sensitivity is improved about 2.1 dB. The downlink data rate is 1.25 Gbit/s and the carrier frequency is 58.1 GHz; the link consists of 6 km optical single-mode fiber and 1 m wireless connection. On the other hand, with the interleaver suppressing downlink OCSR, simultaneously an optical carrier is recovered from the RoF downlink and is reused for RoF uplink transmission. The uplink is operated at 62.9 GHz and the data rate is the same 1.25 Gbit/s. With the recovered optical carrier, a laser-free remote access point is achieved. The principle, structure, and fabrication of an all-fiber optical interleaver are also presented in this paper.     

Design and analysis of the optical transceiver for mobile atmospheric laser communication

The concept of mobile atmospheric laser communication (MALC) is introduced in this paper. Atmospheric attenuation, turbulence-induced scintillation and beam wander cause deep fades in the beam power and degrade the optical channel. The optical transceiver presented in this paper is designed for a MALC test system. Currently achievable hardware performance capabilities for the MALC terminals are used as input parameters to the analysis. A novel optical transceiver structure is designed. Link margin is analyzed using the MALC analysis software, our optical link analysis program. Data rate, bit-error rate, prime transmit