A 40-gb/s InGaAlAs-InAlAs MQW n-i-n Mach-Zehnder Modulator with a drive Voltage of 2.3 V

We have developed a traveling-wave Mach-Zehnder modulator using an n-i-n heterostructure fabricated on an InP substrate. We obtained an extremely small /spl pi/ voltage (V/spl pi/) of 2.2 V, even for a short signal-electrode length of 3 mm. We confirmed that the device has an impedance-matched electrode and operates at 40 Gb/s with a single-ended drive voltage of 2.3 V.     

40 Gbit/s monolithic integrated modulator driver in InP SHBT technology

A high-speed and high-gain modulator driver circuit is presented using 4-inch InP SHBT technology. The IC was developed for driving EAM modulators in 40 Gbit/s optical fibre systems. The monolithic integrated circuit features output amplitude control and output crossing point control. Measured results show the circuit operates at 40 Gbit/s with a swing of 2.5 V/sub p-p/ at each output and 9/8 ps rise/fall times. The power dissipation is 1.5 W with a standard power supply of -5.2 V.     

10 Gbit/s, 1.56 mu m multiquantum well InP/InGaAsP Mach-Zehnder optical modulator

10 Gbit/s modulation using a III-V semiconductor Mach-Zehnder interferometer is reported for the first time. The modulator has a -3 dB bandwidth in excess of 15 GHz and is operated in a push-pull drive configuration with only 2 V peak to peak. 10 Gbit/s nonreturn to zero format eye diagrams with an extinction ratio>10 dB are demonstrated.<>     

40 Gbit/s/ch 2/spl times/2 switch IC using InP HEMTs

A low-power 2/spl times/2 switch IC using InP HEMTs as cold FETs is presented. It has a logic-level-independent interface since no signal line is grounded. The IC yields low insertion loss of 1.5-2.7 dB and high isolation of >21.2 dB below 30 GHz. When two 40 Gbit/s signals were input, error-free operation was confirmed with virtually zero power dissipation.     

40 Gbit/s all-optical demultiplexing using a monolithicallyintegrated Mach-Zehnder interferometer with semiconductor laseramplifiers

The authors demonstrate all-optical error-free demultiplexing of 10, 20 and 40 Gbit/s to 5 Gbit/s data signals by using a monolithically integrated Mach-Zehnder interferometer with two semiconductor laser amplifiers     

40 Gbit/s silicon optical modulator for highspeed applications

A high-speed silicon optical modulator based on the free carrier plasma dispersion effect is presented. It is based on carrier depletion of a pn diode embedded inside a silicon-on-insulator waveguide. To achieve high-speed performance, a travelling-wave design is used to allow co-propagation of the electrical and optical signals along the length of the device. The resulting modulator has a 3 dB bandwidth of ~30 GHz and can transmit data up to 40 Gbit/s.     

InP DHBT-based distributed amplifier for 100 Gbit/s modulator driver operation

A distributed amplifier for use as a modulator driver in next generation optical data communication systems has been manufactured using InP double-hetero bipolar transistor (DHBT) technology with an emitter size of 0.7 times 1 mum². The amplifier achieved a gain of 21 dB and a 3 dB bandwidth of 120 GHz, resulting in a gain-bandwidth product of 1.35 THz. Clearly open 100 Gbit/s 231/1 non-return-to-zero pseudorandom bit sequence (NRZ PRBS) eye diagrams with an output voltage swing of 2.3 V have been measured.     

40 Gbit/s lumped-element modulator driver in GaAs pHEMTs

A high-speed and high-gain modulator driver circuit using 0.15 /spl mu/m gate length GaAs pHEMT technology is presented. The IC was developed for driving electroabsorption modulators in 40 Gbit/s optical fibre systems. To meet application requirements a lumped-element approach was used with differential configuration. Measured results show the circuit operates at 40 Gbit/s with a swing of 3 V/sub p-p/ for single-ended and 6 V/sub p-p/ for differential output, and 8/10 ps rise/fall times.     

40Gbit/s master-slave D-type flip-flop in InP DHBT technology

A D-type flip-flop (MS D-FF) fabricated in a self-aligned InP DHBT technology is presented. 40 Gbit/s on-wafer measurements (limited by measurement setup) show good rise/fall times, low time jitter, as well as important regenerating capabilities. Some important design aspects are highlighted     

All-optical wavelength conversion with multicasting at 6/spl times/10 Gbit/s using electroabsorption modulator

All-optical wavelength conversion with multicasting has been demonstrated with a single electroabsorption modulator based on cross-absorption modulation. It is shown that the input signal wavelength can simultaneously convert to six different wavelengths at 10 Gbit/s, and the relation between the power penalty and the number of simultaneously operating channels is investigated.     

Efficient breakdown voltage doubler for 10 Gbit/s SiGe modulator drivers

A novel intrinsic collector-base capacitance (C_CB) feedback network was incorporated into the series-connected voltage balancing (SCVB) circuit configuration to implement 10 Gbit/s SiGe modulator drivers. The driver fabricated in 0.35 mum SiGe BiCMOS process could output 9 V_PP differential output swing with rise/fall time (20 to 80%) less than 27 ps. Compared with drivers using only SCVB, the power consumption could be greatly reduced from 2 to 1 W     

10-13.6 Gbit/s 0.18 /spl mu/m CMOS modulator drivers with 8 V/sub PP/ differential output swing

A novel intrinsic drain-gate capacitance (C/sub DG/) feedback network is incorporated into the conventional cascode circuit configuration to implement a 10-13.6 Gbit/s modulator driver. The driver fabricated in 0.18 /spl mu/m CMOS process could generate an 8 V/sub PP/ differential output swing. The power consumption is as low as 0.6 W. The present work shows that the driving capability is greater than the currently reported CMOS drivers.     

20 Gbit/s operation of a high-efficiency InGaAsP/InGaAsP MQWelectroabsorption modulator with 1.2-V drive voltage

The authors have fabricated a ridge waveguide electroabsorption modulator based on the quantum-confined Stark effect in InGaAsP/InGaAsP multiple quantum wells. The drive voltage for 12-dB extinction ratio is 1.2 V, and the frequency response is flat within 2 dB from DC to 20 GHz. Operation at 20 Gb/s is reported. Extensive data concerning the parasitic phase modulation (chirping) are obtained as a function of applied bias acid operating wavelength     

High performance 10-12.5 Gbit/s modulator driver in InP SHBT technology

A high performance modulator driver circuit is presented using 4" InP SHBT technology. The IC was developed for driving EAM modulators in OC-192 (10 Gbit/s) and with forward error correction (FEC: 10.7 Gbit/s or 12.5 Gbit/s) optical fibre systems. The monolithic integrated circuit features output amplitude control, output crossing point control and output DC offset control. Measured results show the circuit operates at 10 to 12.5 Gbit/s with a swing of 3.1 V/sub p-p/ at each output and 20/18 ps rise/fall times. The power dissipation is 1.4 W with a standard power supply of -5.2 V.     

Wide temperature range, from 0 to 85/spl deg/C, operation of a 1.55 /spl mu/m, 40 Gbit/s InGaAlAs electro-absorption optical modulator

Wide temperature range, from 0 to 85/spl deg/C, operation of 1.55 /spl mu/m, 40 Gbit/s InGaAlAs multiple quantum well electro-absorption optical modulators is demonstrated for the first time.     

1.6 Tbit/s (40/spl times/40 Gbit/s) DPSK transmission over 3/spl times/100 km of TeraLight fibre with direct detection

By transmitting 40 channels over 300 km of TeraLight fibre, it is shown that optical differential phase shift keying can be used in 100 GHz-spaced 40 Gbit/s systems, with direct detection and a simple receiving filter. Chromatic dispersion tolerance around 300 ps/nm is also measured, compared to 70 ps/nm for NRZ.     

128 Gbit/s high speed optical interconnection networks in data centers by a 30 GHz Mach-Zehnder modulator

A decision feedback equalization (DFE) algorithm is proposed by simplifying Volterra structure. The simplification principle and process of the proposed Volterra-based equalization algorithm are presented. With the support of this algorithm, the signal damage for four-level pulse amplitude modulation signal (PAM-4) is compensated, which is caused by device bandwidth limitation and dispersion during transmission in C-band intensity modulation direct detection (IM-DD) fiber system. Experiments have been carried out to demonstrate that PAM-4 signals can transmit over 2 km in standard single-mode fiber (SSMF) based on a 30 GHz Mach-Zehnder modulator (MZM). The bit error rate (BER) can reach the threshold of hard decision-forward error correction (HD-FEC) (BER=3.8×10-3) and its sensitivity is reduced by 2 dBm compared with traditional feedforward equalization (FFE). Meanwhile, the algorithm complexity is greatly reduced by 55%, which provides an effective theoretical support for the commercial application of the algorithm.     

A 300 V//spl mu/s monolithic voltage follower

An open-loop, JFET input, high-speed buffer, designed without feedback, is described. Careful biasing of source and emitter followers ensures accurate unity gain and gain linearity with 10 mA of load current. A unique quasi-quad input FET layout provides excellent matching and thermal gradient cancellation and simultaneously optimizes speed performance. Offset voltage is permanently adjusted at wafer test by Zener-zap trimming. The output is capable of driving large capacitive loads with 70 mA of peak current.