GaAs MESFET laser-driver IC for 1.7-Gbit/s lightwave transmitter

GaAs monolithic integrated circuits for modulating junction lasers (laser drivers) have been developed for a 1.7-Gb/s lightwave communication system. The modulation currents can be varied continuously from a few mA up to 50 or 100 mA, depending on the types of laser drivers. It has been demonstrated that devices of the low-current type are capable of driving a 50-Ω load with a 50-mA modulation current with pulse rise and fall times (10% to 90%) less than 200 ps, and the high-current devices are capable of driving a 25-Ω load with up to 100-mA modulation current with pulse rise and fall times less than 250 ps. Nearly temperature-independent performance has been achieved from 0°C to 70°C. The laser drivers are also capable of providing output DC currents proportional to the duty cycle of input data for the purpose of duty-cycle-independent feedback control of junction lasers. The circuit designs and performance of these devices are described     

4 Gbit/s GaAs MESFET laser-driver IC

A high-speed laser-driver IC has been fabricated using etched-gate enhancement/depletion-mode MESFET technology. It has been demonstrated that the device is capable of driving 25? load with 80 mA modulation current at up to 4 Gbit/s NRZ data rate.     

GaAs monolithic integrated optical preamplifier

A GaAs monolithic integrated optical preamplifier has been developed based on the transimpedance principle. By associating the amplifier with an external p-i-n diode, a sensitivity of -38 dBm was measured at 140 Mbits/s and 10^-9error rate with a signal wavelength of 1.3 μm. A TiWSiN-integrated technology was used to realize larger than 100-kω feedback resistors and gate leakage could be minimized by improving Schottky contact deposition and employing selective implantation. The optimization details of the FET and resistor elements, as well as the design techniques for integrated transimpedance amplifiers are presented.     

44 Gbit/s GaAs MESFET selector IC

A novel 2:1 selector circuit is described. To achieve high-speed operation, a parallel feedback circuit and inductor peaking were added to a conventional selector circuit. Furthermore, wide bandwidth buffers are carefully designed to cover the operation frequency of this selector circuit. The selector IC, fabricated with 0.1 μm class GaAs MESFETs, operated at up to 44 Gbit/s     

A high-speed GaAs MESFET optical controller

Optical interconnects are being considered for control signal distribution in phased array antennas. A packaged hybrid GaAs optical controller with a 1:16 demultiplexed output that is suitable for this application is described. The controller, which was fabricated using enhancement/depletion mode MESFET technology, operates at demultiplexer-limited input data rates up to 305 Mb/s and requires less than 200 μW optical input power     

Gigabit optical transmitter GaAs MESFET IC

A GaAs optical transmitter IC consisting of input buffers, a D-type flip-flop, an NRZ/RZ code convertor and a light source current driver has been developed for use in fibre-optic communication systems, employing D-MESFET SCFL by the Pt buried gate FET process. 1.1 Gbit/s modulation of an LD in RZ format with 20 mA peak drive current has been demonstrated.     

4-bit multiplexer/demultiplexer chip set for 40-Gbit/s optical communication systems

We have designed and fabricated a low-power 4:1 multiplexer (MUX), 1:4 demultiplexer (DEMUX) and full-clock-rate 1:4 DEMUX with a clock and data recovery (CDR) circuit using undoped-emitter InP-InGaAs HBTs. Our HBTs exhibit an f/sub T/ of approximately 150 GHz and an f/sub max/ of approximately 200 GHz at a collector current density of 50 kA/spl mu/m/sup 2/. In the circuit design, we utilize emitter-coupled logic and current-mode logic series gate flip-flops and optimized the collector current density of each transistor to achieve low-power operation at required high bit rates. Error-free operation at bit rates of up to 50 Gbit/s were confirmed for the 4:1 MUX and 1:4 DEMUX, which dissipates 2.3 and 2.5 W, respectively. In addition, the full-clock-rate 1:4 DEMUX with the CDR achieved 40-Gbit/s error-free operation.     

Evaluation of 4-Gbit/s optical fiber transmission distance with direct and external modulation

Transmission characteristics for a recently modulated measured distributed-feedbacked (DFB) laser and an externally modulated DFB laser using a Ti:LiNbO/sub 3/, Mach-Zehnder modulator at 4 Gb/s are discussed. The transmission characteristics are estimated by an advanced eye-pattern analysis method. The maximum measured fiber dispersion with a directly modulated laser is 100 to 140 ps/nm when the chirp power penalty is 1 dB. However, for external modulation, there is no power penalty after transmission over a 2220-ps/nm dispersive fiber. This confirms that external modulation has superior transmission characteristics. The modulation scheme for 4-Gb/s systems in terms of these results is discussed.<>     

10 Gbit/s AND gate using dual-gate GaAs MESFET

Using a commercial dual-gate GaAs MESFET transistor mounted in a microstrip circuit, an AND gate has been built. With the 100 ps (FWHM) wide test pulses available, a speed of 10 Gbit/s NRZ and a pulse suppression of at least 14 dB was obtained.     

40-Gbit/s OEIC on GaAs substrate through metamorphic buffer technology

An optoelectronic integrated circuit operating in the 1.55-/spl mu/m wavelength range was realized on GaAs substrate through metamorphic technology. High indium content layers, metamorphically grown on a GaAs substrate, were used to fabricate the optoelectronic integrated circuits (OEICs) with -3 dB bandwidth of 40 GHz and 210 V/W of calculated responsivity. The analog OEIC photoreceiver consists of a 12-/spl mu/m, top-illuminated p-i-n photodiode, and a traveling wave amplifier (TWA). This receiver shows 6 GHz wider bandwidth than a hybrid photoreceiver, which was built using comparable, but stand-alone metamorphic p-i-n diode and TWA. With the addition of a buffer amplifier, the OEIC shows 7 dB more gain than the hybrid counterpart. To our knowledge, this is the first 40 Gbit/s OEIC achieved on a GaAs substrate operating at 1.55 /spl mu/m.     

Compact 10-Gbit/s optical transmitter and receiver circuit packs

Compact wideband 10-Gbit/s optical transmitter and receiver circuit packs are realized using high speed analog and digital GaAs IC's as well as a highly thermally conductive board and appropriately designed small function block modules that employ multichip packaging and resonant cavity mode damping. To achieve a compact receiver, the receiver circuit employs a clamp and peak-detector IC in the high speed analog equalizer amplifier to obtain a constant output direct current level for any mark density imbalance in the number of ones and zeros in the signal and a variable phase-shifter IC in the timing circuit. Realized circuit pack size is 200×280×15.24 mm and the power consumption of each pack is about 25 W     

GaAs MESFET physical models for process-oriented design

A detailed physical model which is used to accurately predict the DC and microwave performance of GaAs MESFETs is described. This model, which accounts for hot electron effects in submicron FETs, includes trapping phenomena and heating due to power dissipation. It is used to determine the optimal design for small-signal and power devices, including single- and double-recessed FETs. The spread in device characteristics can be directly related to the variation in device geometry and process parameters experienced in fabrication. The accuracy and flexibility of this approach are demonstrated by comparison with measured data for a variety of devices     

A GaAs MESFET IC for optical multiprocessor networks

A GaAs, enhanced/depletion mode, self-aligned, refractory-gate, MESFET chip process and circuit family have been developed for the integration of fiber-optic data link functions (e.g. photodetection, amplification, clock recovery, and deserialization) on a single chip. These authors describe the process and present results on integrating a complete optical receiver, including the photodiode and clock recovery circuits, on one chip. The chip functions use over 2000 devices, and perform at 1-GB/s, while dissipating less than 300 mW of heat. This chip is the most complex high-performance optoelectronic integrated circuit reported to date     

10Gb XFP光模块的电路板设计

XFP MSA(10Gb小形状因数可插拔多源协议)组织定义了用于数据通信和电信的10Gbps串行收发器,该组织由数据通信行业和电信行业中处于领先地位的网络公司、系统公司、光模块公司、半导体公司以及连接器公司组成(参考文献1).     

Simple common-collector full-monolithic preamplifier for 560 Mbit/s optical transmission

A simple common-collector full-monolithic preamplifier is developed using an advanced 3 ?m Si-bipolar IC technology SICOS. The amplifier characteristics are a 650 MHz bandwidth and a 5.2 pA/?(Hz) equivalent input noise current at a 3 k? transimpedance. Measured optical sensitivity of a front end consisting of the amplifier and a Ge-APD is ?36.2 dBm for an error rate of 10?9 at a 560 Mbit/s bit rate and 1.3 ?m wavelength.     

4-GHz 15-W power GaAs MESFET

High-field behavior of GaAs MESFET's such as drain-source breakdown characteristics and visible light emission and a model explaining these phenomena are described. An FET structure with a high drain-source breakdown voltage in excess of 26 V has been developed following an analysis of the high-field behavior of the device. Typical characteristics of the fabricated devices at 4 GHz are as follows: Pout= 9.6 W Ga= 5 dB ηadd= 33.6 percent at 18 V from single chip (WG= 13 mm) Pout= 15 W Ga= 5 dB ηadd= 28.3 percent at 22 V from two chip (WG= 26 mm) where Pout, Ga, ηadd, and WGindicate the output power, associated power gain, power added efficiency, and total gate width of the FET's, respectively.     

2.24-Gbit/s 151-km optical transmission system using high-speedintegrated silicon circuits

Optical transmission experiments performed at 2.24 Gb/s using standard single-mode fiber with dispersion zero at 1.3 μm are discussed. In the optical transmitter, a 1.5-μm-wavelength distributed feedback laser is directly modulated by means of a special electrical drive pulse shaping technique. A link length of up to 151 km is bridged. This is the longest repeater distance at 2 Gb/s using direct detection without optical amplifiers reported so far. Moreover, the transmission system includes multiplexing and demultiplexing equipment using specially developed high-speed silicon integrated circuits. The whole system is assembled in a version suitable for field trial applications     

160-Gbit/s clock recovery using an electro-absorption modulator and 40-Gbit/s ETDM demultiplexer

A 10-GHz clock recovery from a 16×10-Gbit/s optical time-division-multiplexed (OTDM) data stream is experimentally demonstrated using an electro-absorption modulator and 40-Gbit/s electric time-division-multiplexed (ETDM) demultiplexer. The recovered clock signal exhibits excellent stability, with root square (RMS) jitter of 328 and 345 fs corresponding to back-to-back and transmission over 100 km, respectively.     

Monolithic PIN/preamplifier circuit integrated on a GaAs substrate

An AlGaAs/GaAs PIN photodiode and a GaAs transimpedance amplifier including six FETs have been monolithically integrated on a GaAs substrate. A photoreceiver operation exhibiting an excellent linearity has been demonstrated. The photodiode sensitivity of 0.44 A/W and the amplifier transimpedance of 1.0 × l04 V/A have been determined from the measurement.