Single mode fiber MT-RJ SFF transceiver module using opticalsubassembly with a new shielded silicon optical bench

Demand for a compact cost reduced optical transceiver has arisen. Small form factor (SFF) optical transceivers are expected to meet this demand. A new concept optical module based on V-grooved silicon optical bench (SiOB) technology, that enables a passive alignment of optical fibers and optical devices is expected to reduce the cost. MT-RJ SFF optical transceivers require this new packaging technique because the distance between input and output optical axes is shorter than conventional transceivers. However, crosstalk between a transmitter and a receiver is a big issue to be solved because the distance between optical axes of the laser diode (LD) and the photo diode (PD) is only 0.75 mm. It is difficult to reduce the crosstalk in a SiOB because large electromagnetic coupling exists due to the conductivity of a silicon substrate. A newly developed, low crosstalk optical subassembly (OSA) with a single mode fiber MT-RJ receptacle and the SFF transceiver module are reported. We have analyzed a mechanism of electrical crosstalk in a SiOB and developed a shield structure to reduce it. The crosstalk in the OSA with shielded SiOB was reduced over 20 dB compared to the unshielded SiOB     

Agilent technologies' singlemode small form factor (SFF) moduleincorporates micromachined silicon, automated passive alignment, andnon-hermetic packaging to enable the next generation of low-cost fiberoptic transceivers

Agilent Technologies (formerly Hewlett-Packard) are currently manufacturing a range of multimode and singlemode (SM) SFF transceivers with data rates from 125 Mb/s to 1.25 Gb/s (higher data rates are being developed). This paper will address the singlemode module design, assembly techniques and performance. The SFF transceivers offer the same functionality as SC duplex transceivers but utilize the mini MT-RJ optical interface in order to achieve twice the port density. Test results that demonstrate the performance of the mini MT-RJ optical interface will be presented. The SFF modules are price competitive with SC duplex modules, and are designed to enable low cost, high volume manufacture. In order to meet the size constraints and achieve low manufacturing costs, the SM SFF transceiver utilizes silicon as a base to support the optical fibers and active components, and as an aid to passively align of the active components to the fibers. Most other passively aligned modules require the use of a more expensive expanded mode region laser diode (LD). But Agilent Technologies have developed a unique passive align and attach system that can easily achieve the required coupling power for fast ethernet, OC3 and gigabit ethernet using a standard 1300 mn Strained Multiquantum Well (SMQW) LD. The module design and the methods used for passive align will be discussed, as will the precision die attach (PDA) equipment. All precious Agilent Technologies/Hewlett-Packard SM modules relied on an Hermetic cavity around the active devices to achieve the reliability assurance, e.g., as defined in Bellcore TA-NWT-000983, but this type of Hermetic design has limited potential for cost reduction. The SM SFF module is designed to meet the same assurance levels, but uses silicone encapsulation in place of Hermeticity, and the results of the qualification testing will be presented     

A Single-Chip CMOS-Based Parallel Optical Transceiver Capable of 240-Gb/s Bidirectional Data Rates

We report here on the design, fabrication, and high-speed performance of a parallel optical transceiver based on a single CMOS amplifier chip incorporating 16 transmitter and 16 receiver channels. The optical interfaces to the chip are provided by 16-channel photodiode (PD) and VCSEL arrays that are directly flip-chip soldered to the CMOS IC. The substrate emitting/illuminated VCSEL/PD arrays operate at 985 nm and include integrated lenses. The complete transceivers are low-cost, low-profile, highly integrated assemblies that are compatible with conventional chip packaging technology such as direct flip-chip soldering to organic circuit boards. In addition, the packaging approach, dense hybrid integration, readily scales to higher channel counts, supporting future massively parallel optical data buses. All transmitter and receiver channels operate at speeds up to 15 Gb/s for an aggregate bidirectional data rate of 240 Gb/s. Interchannel crosstalk was extensively characterized and the dominant source was found to be between receiver channels, with a maximum sensitivity penalty of 1 dB measured at 10 Gb/s for a victim channel completely surrounded by active aggressor channels. The transceiver measures 3.25times5.25 mm and consumes 2.15 W of power with all channels fully operational. The per-bit power consumption is as low as 9 mW/Gb/s, and this is the first single-chip optical transceiver capable of channel rates in excess of 10 Gb/s. The area efficiency of 14 Gb/s/mm² per link is the highest ever reported for any parallel optical transmitter, receiver, or transceiver reported to-date.     

30Gbit/s并行光接收模块

报道了一种基于CMOS工艺接收电路芯片和GaAs工艺1×12光电探测器阵列的30Gbit/s并行光接收模块.该模块采用并行光通信方案,利用中高速光电子器件实现信号的高速传输.直接使用未经封装的接收电路裸片和光探测器裸片,采用电路板上芯片技术封装制作模块,并通过倒装焊的方式实现了探测器阵列与列阵光纤的精确对准并形成了可插拔的光接口.测试结果表明模块的接收能力可以达到30Gbit/s.误码率小于10-13时,接收模块的灵敏度可以达到-13.6dBm.     

30Gbit/s Parallel Optical Receiver Module

报道了一种基于CMOS工艺接收电路芯片和GaAs工艺1×12光电探测器阵列的30Gbit/s并行光接收模块.该模块采用并行光通信方案,利用中高速光电子器件实现信号的高速传输.直接使用未经封装的接收电路裸片和光探测器裸片,采用电路板上芯片技术封装制作模块,并通过倒装焊的方式实现了探测器阵列与列阵光纤的精确对准并形成了可插拔的光接口.测试结果表明模块的接收能力可以达到30Gbit/s.误码率小于10-13时,接收模块的灵敏度可以达到-13.6dBm.     

A novel transmitter/receiver switching circuit configuration forhigh-performance LD transceiver in subscriber loop

LD (laser diode) transceivers are very effective in reducing optical subscriber systems cost because they act as transmitters and receivers. This paper proposes a new transceiver switching circuit configuration, and two techniques for suppressing and canceling the discharge current effect of laser diodes. The new techniques, including mounting substrate optimization such as high-isolation and low parasitic capacitance, yield a high-performance LD transceiver module with the minimum average receiving optical power level of -37.0 dBm and a wide dynamic range of up to 25 dB for burst mode optical input at 29.0 Mb/s     

Low-cost WDM-PON with colorless bidirectional transceivers

This paper presents a low-cost bidirectional (BiDi) wavelength-division-multiplexed passive optical network (WDM-PON) employing colorless uncooled BiDi transceivers (TRxs) and superluminescent diode (SLD)-based broadband light sources (BLSs). The C band is allocated for upstream and the E+ band for downstream in consideration of BiDi packaging, SLD development, and wavelength alignment of dual-window arrayed waveguide gratings (AWGs). The BiDi TRx integrates an uncooled Fabry-Perot laser diode (FP-LD), a p-i-n photodiode (PD), and a 45/spl deg/-angled thin-film filter in a small-form-factor (SFF) package. The SLD-based BLSs provide 13-dBm amplified spontaneous emissions (ASEs) with spectral ripples of < 3 dB and polarization dependencies of <1 dB. Colorless operations over 32 100-GHz-spaced channels are demonstrated from -20 to 80/spl deg/C in 155-Mb/s BiDi transmissions over 25 km.     

Low-cost and low-electromagnetic-interference packaging of optical transceiver modules

The low-cost and low-electromagnetic-interference (EMI) packaging of optical transceiver modules employing housings of plastic composites are developed and fabricated. Optical transceiver modules fabricated by the plastic composites with transmission rates of 1.25 and 2.5 Gb/s are tested to evaluate the electromagnetic (EM) shielding against emitted radiation from the plastic packaging. The results show that these packaged optical transceiver modules with their high shielding effectiveness (SE) are suitable for use in low-cost and low-EMI Gigabit Ethernet lightwave transmission systems. By comparison of cost, weight, and shielding performance for optical transceiver modules fabricated by the housings of nylon and liquid-crystal polymer with carbon fiber filler composites, woven continuous carbon fiber (WCCF), and nanoscale hollow carbon nanocapulses (HCNCs) epoxy composites, the WCCF composite shows lower cost, lighter weight, and higher EM shielding than the other types of composites. Future studies may develop the low-cost and low-EMI optical transceiver modules using nanoscale HCNCs that have the combination of excellent physical and mechanical properties, light weight, and thinness compared with the conventional fabrication techniques.     

Next-generation 10 GBaud module based on emerging SFP+ with host-based EDC [Topics in Optical Communications]

There has been an ongoing trend to require transceivers for use in datacom and telecom switches to be small and have low power dissipation to enable large port count switches. At speeds between 1 and 4 GBaud the SFP form factor is by far the most commonly used. Up to now 10 GBaud transceivers have used larger devices with larger power dissipations. This article describes the SFP+ module being specified by the SFF Committee (SFF 8431) that will enable the same port densities as the SFP module. The adaptive equalizers and high-speed transmission channels required in the switches to make the SFP+ module work successfully are also described     

基于单芯片技术和垂直腔面发射激光器的光纤与光电器件被动无源对准光互连

在平行光互接应用的光收发器中,光纤对准占据了光电封装成本的一大部分。文章研究的光发送器和接收器由工作波长950nm的垂直腔面发射激光器（VCSELs）和谐振腔增强型（RCE）光检测器组成,并键合到单个双极型互补金属氧化物半导体（BiCMOS）芯片上。考虑到性能与生产成本,对不同的组装结构进行了研究。最终选择了利用倒装技术将光芯片键合到集成电路（IC）的方法。为实现光纤的被动无源对准,提出了在一片倒装焊了光芯片的IC上方叠放的硅片上蚀刻孔的设想。目前这样一种测试装置已由法国LETI开发出来,并通过它证明了采用这种方法能够获得高精度（μm）的光纤对准。     

Effective electromagnetic shielding of plastic packaging in low-cost optical transceiver modules

A low-cost plastic package of the standard 1 /spl times/ 9 type with effective electromagnetic (EM) shielding ability is developed. Optical transceiver modules with transmission rates of 155 Mb/s and 1.25 Gb/s are tested to evaluate the EM shielding against emitted radiation from the plastic packaging. The results show that the packaged optical transceiver modules exhibit shielding effectiveness (SE) of over 20 dB. The EM shielding properties of plastic materials consisting of nylon66 and liquid crystal polymer (LCP) with carbon fiber reinforced are investigated. The effects of weight percentage of fibers, carbon fiber length, and material thickness on the SE of the plastic composites are studied both from the plane-wave and near-field sources approaches. The packaged plastic optical transceiver modules with their good SE are suitable for use in low-cost and low electromagnetic interference (EMI) Gigabit Ethernet lightwave transmission systems.     

Packaging for a 40-channel parallel optical interconnection modulewith an over-25-Gbit/s throughput

NTT is currently working on developing a high-throughput interconnection module that is both compact and cost effective. The technology being developed is called “parallel inter-board optical interconnection technology”, or “ParaBIT”. The ParaBIT module that has been developed is the first step; it is a front-end module with 40 channels, a throughput of over 25 Gbit/s, and a transmission distance of over 100 m along multimode fibers. One major feature of this module is the use of vertical-cavity surface-emitting laser (VCSEL) arrays as very cost-effective light sources. These arrays enable the same packaging structure to be used for both the transmitter and receiver. To achieve super-multichannel performance, high-density multiport bare-fiber (BF) connectors were developed for the module's optical interface. Unlike conventional optical connectors, these BF connectors do not need a ferrule or spring. This ensures physical contact with an excellent insertion loss (less than 0.1 dB per channel). A polymeric optical waveguide film with a 45° mirror for coupling to the VCSEL and photo-diode (PD) arrays by passive optical alignment was also developed. To facilitate coupling between the VCSEL/PD array chips and the waveguide, a packaging technique was developed to align and die bond the optical array chips on a substrate. This technique is called transferred multichip bonding (TMB); it can be used to mount optical array chips on a substrate with a positioning error of only several micrometers. These packaging techniques enabled ultra-parallel interconnections to be achieved in prototype ParaBIT modules     

200Gbit/s PAM4光发射组件封装技术研究

针对200Gbit/s PAM4光收发模块的设计需求,提出了一种基于四阶脉冲幅度调制(PAM4)、数据传输速率达200Gbit/s的光发射组件封装方案。该封装内部集成了4路PAM4电/光转换通道,单通道数据传输速率为50Gbit/s。介绍了该200Gbit/s PAM4光发射组件的组成和技术难点,然后对其中的50Gbit/s数据传输通道进行了建模、仿真和优化,最后完成了样品的测试。测试结果表明:样品的单通道PAM4数据速率可达50Gbit/s,整体PAM4数据速率可达200Gbit/s,满足光收发模块的设计需求。     

10Gbit/s XFP光模块的设计

文章介绍了应用于光网络系统的10Gbit/s XFP(小型化可热插拔)光模块的基本原理以及光收发模块的设计,采用了CDR(时钟数据恢复)、APC(自动功率控制)、LA(限幅放大器)和发射驱动集成的主芯片GN2010EA,与传统设计相比不仅降低了设计成本,而且降低了设计的复杂度。测试结果表明,该模块在宽的温度范围内能保持稳定的光功率和消光比,并且指标满足ITU-T标准的要求,符合10Gbit/s光模块设计要求。     

满足10Gbit/s以太网应用的激光器优化多模光纤

本介绍了使用于10Gbit／s以太网技术的激光器优化新一代50／125um多模光纤，这种多模光纤在10Gbit／s局域网系统中850nm波长的传输距离大干300m，具有经济性，兼容性和易于升级的特点。长飞公司的超贝光纤系列符合相关的国际标准，相应的传输距离可以达到150m，300m，和500m以上。     

Optical Transceivers for Fiber-to-the-Premises Applications: System Requirements and Enabling Technologies

A comprehensive review of the optical transceivers for fiber-to-the-premises applications is presented, with emphasis on system requirements and enabling technologies. Recent progress in photonic integration to realize low-cost, high-performance, and compact optical transceivers for the optical network terminal is reviewed     

Three-Optical-Port Module for Monolithic Optical Gate Integrated With Photodiode and Electroabsorption Modulator

Compact and stable three-optical-port modules are developed for optical gate devices monolithically integrated with photodiodes and electroabsorption modulators. The module has the same package size as ordinary laser-diode (LD) modules, and has three pigtailed fibers on two sides and the top. The module has high coupling efficiency and high stability for every optical port     

Design considerations for transceiver-limited elastic optical networks

The continuous increase of data traffic for present-day applications necessitates the development of Elastic Optical Networks (EONs). Significant advancements in efficient Routing and Spectrum Assignment (RSA) algorithms for EONs have been noticed in the recent past. These existing algorithms did not mention constraints on the number of transceivers per node in a network. However, for the planning of a realistic network, it is necessary to estimate the number of transceivers required at each node for the efficient operation of a network. Therefore, transceiver constraints should be taken into account while designing the RSA algorithms. In this paper, we present the impact of putting a limit to the number of transmitters and receivers available at each node of an EON. Moreover, the cost of a network heavily depends on the number of transceivers that each node in the network may offer. Hence, estimating the required number of transceivers per node in a network is vital to approximate the design cost of a network. Here, we present an Integer Linear Programming (ILP) formulation that includes the transceiver constraints and also develop a transceiver-aware heuristic algorithm for routing and spectrum assignment in EONs. Simulation results help us provide a proper design tool to estimate the number of transceivers per node in elastic optical networks.

     

2.5 Gbit/s multifunctional CMOS transceiver for chip-to-chip optical link

A novel multifunctional transceiver for chip-to-chip optical interconnects operating at 2.5 Gbit/s is proposed, which shares a common block between a receiver and a transmitter. This transceiver provides four conversion functions - electrical-to-optical, optical-to-optical, optical-to-electrical, and electrical-to-electrical - depending on the selection switch on a single chip. The whole chip integrated in 0.18 /spl mu/m CMOS occupies an area measuring 0.82/spl times/0.82 mm/sup 2/.     

C4NP-无铅倒装晶片焊凸形成生产工艺与可靠性数据

受控倒塌芯片连接新工艺是一种由IBM公司开发、由Suss Micro Tec公司推向商品化的新型焊凸形成技术。受控倒塌芯片连接新工艺采用各种无铅焊料合金致力于解决现有的凸台。形成技术限定,使低成本小节距焊凸形成成为可能。受控倒塌芯片连接新工艺是一种焊球转移技术,熔焊料被注入预先制成并可重复使用的玻璃模板(模具)。这种注满焊料的模具在焊料转入圆片之前先经过检查以确保高成品率。注满焊料的模具与圆片达到精确的接近后以与液态熔剂复杂性无关的简单工序转移在整个300mm(或300mm以下)圆片上。受控倒塌芯片连接新工艺技术能够在焊膏印刷中实现小节距凸台形成的同时提供相同合金选择的适应性。这种简单的受控倒塌芯片连接新工艺使低成本、高成品率以及快速封装周期的解决方法对于细节距FCiP以及WLCSP凸台形成均能适用。