超高速激光驱动器电路设计与研制

分别利用0.35μm CMOS工艺和0.2μm GaAs PHEMT(pseudomorphic high electron mobility transistor)工艺实现了激光驱动器集成电路,其工作速率分别为2.5Gb/s和10Gb/s,可应用于光纤通信SDH(synchronous digital hierarchy)传输系统.     

10GHz 2分频器芯片设计

目前,10 Gb/s以上的数字光纤通信技术正在逐步得到应用,研究和开发光纤通信用的高速集成电路具有重要的意义。文章介绍了使用0.2μm GaAs HEMT工艺设计的1个10 Gb/s以上的光纤传输用2分频器。该分频器采用双锁存器串联结构,仿真结果和流片测试结果均表明该电路在10Gb/s的速率上可以完成2分频功能。     

A 3.125-Gb/s inductroless transimpedance amplifier for optical communication in 0.35μm CMOS Xu Hui(徐晖), Feng Jun(冯军), Liu Quan(刘全), Li Wei(李伟)

采用0.35μm CMOS工艺设计了一种适用于光通信的低功耗前置放大器,芯片最高工作速率可达3.125Gb/s。该前置放大器采用RGC (Regulated Cascode)结构作为输入级,同时引入消直流电路来稳定电路的直流工作点。在片测试结果表明,前置放大器的跨阻增益为54.2dBΩ,-3dB带宽为2.31GHz,平均等效输入噪声电流谱密度为18.8pA/?Hz;输入为2.5Gb/s和3.125Gb/s信号时均可获得清晰眼图;3.3V单电源供电时,功耗仅为58.08mW,其中20mW来自输出缓冲。芯片面积为465μm435μm。     

一种 65纳米 CMOS 10–20 Gb/s PAM2-4接收和发送端

本文提出了65纳米CMOS工艺下的一种 10Gb/s PAM2, 20Gb/s PAM4高速低功耗的有线电互连发送和接收端。发送端面积为430μm × 240μm,功耗为 50.56mW。通过集成可编程的 5阶预加重均衡器,发送端可以在宽范围区间内补偿各种不同的信道损失,并且针对信道特点的不同采用相应的发送电压幅度从而降低信号发送功耗。接收端均衡器面积为146μm × 186μm,功耗为5.3mW。     

一种数据时钟恢复电路的研究与设计

提出了一种支持双数据率的数据时钟恢复电路,对电路中的鉴相器、环路滤波器、压控振荡器等进行了详细的分析研究和设计.基于0.18μm CMOS工艺,在电源电压1.8V下对电路进行仿真.仿真结果显示,电路在2.7 Gb/s和1.62 Gb/s随机流下的抖动峰峰值分别为14 ps和12ps,功耗为80 mW.测试结果显示,时钟恢复电路在2.7 Gb/s和1.62 Gb/s随机流下的抖动峰峰值分别为38 ps和27 ps.     

10Gb/s×12通道VCSEL驱动器阵列设计

采用0.18μm CMOS工艺设计了12通道并行垂直腔面发射激光器(VCSEL:Vertical CavitvSurface Emitt ing Laser)驱动阵列.仿真结果表明,1.8V电源供电时,该电路单通道输出调制电流可达30mA,工作速率为10Gb/s,最大可达12Gb/s,12路并行通道的总带宽为120Gb/s,该驱动阵列电路可用于高速芯片间光互连.     

2.5Gb/s单片时钟恢复数据判决与1:4分接集成电路的设计

用0.25μm CMOS工艺实现一个复杂的高集成度的2.5Gb/s单片时钟数据恢复与1:4分接集成电路.对应于2.5Gb/s的PRBS数据(231-1),恢复并分频后的625MHz时钟的相位噪声为-106.26dBc/Hz@100kHz,同时2.5Gb/s的PRBS数据分接出4路625Mb/s数据.芯片面积仅为0.97mm×0.97mm,电源电压3.3V时核心功耗为550mW.     

0.25μm CMOS工艺实现的3.125 Gb/s×12通道VCSEL驱动器阵列

本文介绍了一种利用0.25μm CMOS工艺实现的12通道垂直腔面发射激光器(VCSEL)阵列驱动器电路.该电路采用3.3V单电源供电,单通道最大输出调制电流超过30毫安,单通道工作速率达到3.125Gb/s,12个并行通道的总带宽为37.5Gb/s.     

0．18μm CMOS工艺10Gb／s VCSEL电压驱动器设计

采用SMIC0．18μm1P6M混合信号CMOS工艺设计了10Gb／sVCSEL电压驱动器,可以用于驱动共阴结构的VCSEL。电路采用了RC负反馈技术和C3A（电容耦合电流放大器）结构,仿真结果表明,电路在10Gb／s速率下工作性能良好,最高可工作至12．5Gb／s。电路采用1．8V和3．5V电压供电,直流总功耗为164mw。     

2.5 Gbit/s光接收机电路的全集成

提供了应用于光纤传输系统同步数字体系(SDH)STM-16级别(2.5 Gb it/s)的全集成光接收机电路的设计。采用TSMC 0.25μm CMOS工艺进行流片。芯片对应于5μA的2.5 Gb it/s的PRBS输入码流(231-1),可恢复出一路1.25 GHz时钟,同时将2.5 Gb it/s的PRBS数据分接成4路625 Mb it/s数据,输出的时钟与数据均为标准的400 mV的PCML电平。芯片面积为1.04 mm×0.97 mm,电源电压为3.3 V时功耗为850 mW。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its