Filipe Jorge

Generation and Transmission of 21.4-Gbaud PDM 64-QAM Using a Novel High-Power DAC Driving a Single I/Q Modulator

We generate a single-carrier 21.4-Gbaud polarization-division-multiplexed (PDM) 64-ary quadrature-amplitude-modulated (QAM) signal (256.8-Gb/s line rate) using a single in-phase/quadrature (I/Q) optical modulator driven by 8-level electrical waveforms from a novel high-power digital-to-analog converter (DAC). We measure a required optical signal-to-noise ratio of 29.5 dB (0.1-nm reference bandwidth; 10-3 bit-error rate), 4.6-dB off the theoretical limit. Using ultra-large-area fiber, we achieve 400-km single-channel transmission. The DAC was also used to obtain excellent results with quadrature-phase-shift-keyed and 16-QAM signals at 21.4 Gbaud.

Submicron InP DHBT Technology for High-Speed High-Swing Mixed-Signal ICs

We report on the development of a submicron InP DHBT technology, optimized for the fabrication of ges50-GHz- clock mixed-signal ICs. In-depth study of device geometry and structure has allowed to get the needed performances and yield. Special attention has been paid to critical thermal behavior. Various size submicron devices have been modeled using UCSD- HBT equations. These large signal models have allowed the design of 50-GHz clocked 50 G Decision and 100 G Selector circuits. The high quality of the measured characteristics demonstrates the suitability of this technology for the various applications of interest, like 100 Gbit/s transmission.

WDM transmission at 6-Tbit/s capacity over transatlantic distance, using 42.7-Gb/s differential phase-shift keying without pulse carver

We report the transmission of a record 6 Tbit/s capacity over 6120 km distance, involving channels modulated at 42.7-Gb/s bit-rate with differential phase-shift keying (DPSK). The performance is found similar to DPSK with subsequent pulse carving, namely RZ-DPSK.

Evanescently coupled photodiodes integrating a double-stage taper for 40-Gb/s applications-compared performance with side-illuminated photodiodes

The design, fabrication, and performance of double-stage taper photodiodes (DSTPs) are reported. The objective of this work is to develop devices compatible with 40-Gb/s applications. Such devices require high efficiency, ultrawide band, high optical power handling capability, and compatibility with low-cost module fabrication. The integration of mode size converters improves both the coupling efficiency and the responsivity with a large fiber mode diameter. Responsivity of 0.6 A/W and 0.45 A/W are achieved with a 6-/spl mu/m fiber mode diameter and cleaved fiber, respectively, providing relaxed alignment tolerances (/spl plusmn/1.6 /spl mu/m and /spl plusmn/2 /spl mu/m, respectively), compatible with cost-effective packaging techniques. DSTPs also offer a wide bandwidth greater than 40 GHz and transverse-electric/transverse-magnetic polarization dependence lower than 0.2 dB. Furthermore, a DSTP saturation current as high as 11 mA results in optical power handling greater than +10 dBm and a high output voltage of 0.8 V. These capabilities allow the photodiode to drive the decision circuit without the need of a broad-band electrical amplifier. The DSTP devices presented here demonstrate higher responsivities with large fiber mode diameter and better optical power handling capabilities and are compared with classical side-illuminated photodiodes.

Spectrally efficient long-haul transmission of 22-Tb/s using 40-Gbaud PDM-16QAM with coherent detection

We report on the transmission of 1-Tb/s clusters of channels, composed by four 50-GHz-spaced WDM channels modulated with 40-Gbaud PDM-16QAM. We transmit 22-Tb/s data over 2,400 km, with a spectral efficiency of 5 bit/s/Hz.

DC-100-GHz frequency doublers in InP DHBT technology

Broad-band monolithic integrated active frequency doublers operating in dc-100-GHz frequency range are presented. Circuits are fabricated in a self-aligned InP double heterojunction bipolar transistor process. Three integrated doubler versions have been designed. Inductive peaking and active splitting effects are quantified and compared. Circuit measurements give sinusoidal output waveform at 100 GHz with an rms timing jitter of 400 fs. Circuits have a maximum conversion gain of +1 dB at 60 GHz. the fundamental suppression is better than 24 dB in the whole frequency range.

Single-carrier 400G interface and 10-channel WDM transmission over 4,800 km using all-ETDM 107-Gbaud PDM-QPSK

We transmit all-electronically multiplexed 107-Gbaud polarization-multiplexed quadrature-phase-shift-keying over 4,800-km using coherent detection based on a real-time oscilloscope with 63-GHz electronic bandwidth. Ten WDM channels on a 120-GHz grid yield a spectral efficiency of 3.3 b/s/Hz.

Serial 100 Gb/s connectivity based on polymer photonics and InP-DHBT electronics.

We demonstrate the first integrated transmitter for serial 100 Gb/s NRZ-OOK modulation in datacom and telecom applications. The transmitter relies on the use of an electro-optic polymer modulator and the hybrid integration of an InP laser diode and InP-DHBT electronics with the polymer board. Evaluation is made at 80 and 100 Gb/s through eye-diagrams and BER measurements using a receiver module that integrates a pin-photodiode and an electrical 1:2 demultiplexer. Error-free performance is confirmed both at 80 and 100 Gb/s revealing the viability of the approach and the potential of the technology.

All-ETDM 80-Gbaud (160-Gb/s) QPSK Generation and Coherent Detection

A single-polarization 160-Gb/s (80-Gbaud) electronically time-division-multiplexed (ETDM) quadrature phase-shift-keyed (QPSK) signal is generated and coherently detected using two 45-GHz-bandwidth oscilloscope prototypes and offline processing.

39.4-Gb/s Duobinary Transmission Over 24.4 m of Coaxial Cable Using a Custom Indium Phosphide Duobinary-to-Binary Converter Integrated Circuit

We show, for the first time, duobinary transmission of 39.4-Gb/s data over a 24.4-m-long 5.2-mm-diameter coaxial cable with SMA connectors, enabled by the design of a custom 40-Gb/s HBT indium phosphide duobinary-to-binary converter integrated circuit (IC). We achieve a bit error rate better than 3 times 10-12 with a 215- 1 b sequence, using clock recovery. The transmission experiment and design of the duobinary-to-binary converter IC are discussed in detail.