Tandem electroabsorption modulators integrated with DFB laser by ultra-low-pressure selective-area-growth MOCVD for 10 GHz optical short pulse generation - art. no. 60200O

A novel device of tandem multiple quantum wells (MQWs) electroabsorption modulators (EAMs) monolithically integrated with DFB laser is fabricated by ultra-low-pressure (22 mbar) selective area guowth (SAG) MOCVD technique. Experimental results exhibit superior device characteristics with low threshold of 19 mX output light power of 4.5 mW and over 20 dB extinction ratio when coupled into a single mode Fiber. Moreover, over 10 GHz modulation bandwidth is developed with a driving voltage of 2 V. Using I this sinusoidal voltage driven integrated device, 10GHz repetition rate pulse with a width of 13.7 ps without any compression elements is obtained.

Silicon-on-insulator based optical waveguide and integrated switch matrix

zhangdi于2010-03-29批量导入

Fabrication of a novel silica PLC hybrid integrated triplexer

A new-style silica planar lightwave circuit (PLC) hybrid integrated triplexer, which can demultiplex 1490-nm download data and 1550-nm download analog signals, as well as transmit 1310-nm upload data, is presented. It combines SiO2 arrayed waveguide gratings (AWGs) with integrated photodetectors (PDs) and a high performance laser diode (LD). The SiO2 AWGs realize the three-wavelength coarse wavelength-division multiplexing (CWDM). The crosstalk is less than 40 dB between the 1490- and 1550-nm channels, and less than 45 dB between 1310- and 1490- or 1550-nm channels. For the static performances of the integrated triplexer, its upload output power is 0.4 mW, and the download output photo-generated current is 76 A. In the small-signal measurement, the upstream 3-dB bandwidth of the triplexer is 4 GHz, while the downstream 3-dB bandwidths of both the analog and digital sections reach 1.9 GHz.

An Integrated Solution for Software Process Improvement

Since 1990s, the software industry in China has been developed very rapidly and the total revenue in recent three years of 2005, 2006 and 2007 were 390.0, 480.0, and 583.4 billions RMB respectively, increased by 28.3% annually on an average basis [1]. By the end of 2007, there were about 18,000 software enterprises in China, and the population of software professionals was 1.48 millions roughly. In the global software market, China, with annual revenue about 82.2 billions USD (8.74% of the total: 940 billions USD), currently ranks on the fourth after USA, EU and Japan. However, the software industry in China is still comparatively weak. Most software enterprises have only tens of employees and millions RBM of revenue. And the software development productivity in China varies highly across the software industry in terms of organization, development type, business area, region, language, project size and team size [2]. Co-operative efforts from the government, the industry and the academy are needed [3]. Continuous software process improvement is an effective way to change the challenging situation of the software industry in China.

Design and operation of integrated pilot-scale dimethyl ether synthesis system via pyrolysis/gasification of corncob

The integrated pilot-scale dimethyl ether (DME) synthesis system from corncob was demonstrated for modernizing utilization of biomass residues. The raw bio-syngas was obtained by the pyrolyzer/gasifier at the yield rate of 40-45 Nm(3)/h. The content of tar in the raw bio-syngas was decreased to less than 20 mg/Nm(3) by high temperature gasification of the pyrolysates under O-2-rich air. More than 70% CO2 in the raw bio-syngas was removed by pressure-swing adsorption unit (PSA). The bio-syngas (H-2/CO approximate to 1) was catalytically converted to DME in the fixed-bed tubular reactor directly over Cu/Zn/Al/HZSM-5 catalysts. CO conversion and space-time yield of DME were in the range of 82.0-73.6% and 124.3-203.8 kg/m(cat)(3)/h, respectively, with a similar DME selectivity when gas hourly space velocity (GHSV, volumetric flow rate of syngas at STP divided by the volume of catalyst) increased from 650 h(-1) to 1500 h(-1) at 260 degrees C and 4.3 MPa. And the selectivity to methanol and C-2(+) products was less than 0.65% under typical synthesis condition. The thermal energy conversion efficiency was ca. 32.0% and about 16.4% carbon in dried corncob was essentially converted to DME with the production cost of ca. (sic) 3737/ton DME. Cu (111) was assumed to be the active phase for DME synthesis, confirmed by X-ray diffraction (XRD) characterization.

Design and Operation of A 5.5 MWe Biomass Integrated Gasification Combined Cycle Demonstration Plant

The design and operation of a 5.5 MWe biomass integrated gasification combined cycle (IGCC) demonstration plant, which is located in Xinghua, Jiangsu Province of China, are introduced. It is the largest complete biomass gasification power plant that uses rice husk and other agricultural wastes as fuel in Asia. It mainly consists of a 20 MWt atmospheric circulating fluidized-bed gasifier, a gas-purifying system, 10 sets of 450 kW(e) gas engines, a waste heat boiler, a 1.5 MWe steam turbine, a wastewater treatment system, etc. The demonstration plant has been operating since the end of 2005, and its overall efficiency reaches 26-28%. Its capital cost is less than 1200 USD/kW, and its running cost is about 0.079 USD/kWh based on the biomass price of 35.7 USD/ton. There is a 20% increment on capital cost and 35% decrease on the fuel consumption compared to that of a 1 MW system without a combined cycle. Because only part of the project has been performed, many of the tests still remain and, accordingly, must be reported at a later opportunity.

A High Speed, 12-Channel Parallel, Monolithic Integrated CMOS OEIC Receiver

The design and fabrication of a high speed, 12-channel monolithic integrated CMOS optoelectronic integrated circuit(OEIC) receiver are reported.Each channel of the receiver consists of a photodetector,a transimpedance amplifier,and a post-amplifier.The double photodiode structure speeds up the receiver but hinders responsivity.The adoption of active inductors in the TIA circuit extends the-3dB bandwidth to a higher level.The receiver has been realized in a CSMC 0.6μm standard CMOS process.The measured results show that a single channel of the receiver is able to work at bit rates of 0.8～1.4Gb/s. Altogether, the 12-channel OEIC receiver chip can be operated at 15Gb/s.