J.B. Rosolem

Experimental demonstration and numerical simulation of an optical recirculating loop operating at 10 gb/s

We demonstrate an optical recirculating loop as a tool for performance evaluation of cascades of effects or elements in an optical communication system. We describe the critical issues to operate the recirculating loop properly and we present experimental results on the cascading of a dispersive fiber link and an optical amplifier. Additionally, we conduct a numerical simulation of the recirculating loop experimental conditions. Simulation and experimental results are in good agreement.

Triple Band Silica Based Double Pass EDFA with an Embedded DCF Module for CWDM Applications

We present a double pass triple-band EDFA with an embedded DCF experimentally characterized over the CWDM grid. It is shown that the amplifier can extend the bus topology link length beyond the 100 km limit

Thulium doped fiber amplifier performance in S band using two different complementary pumping wavelengths

We have characterized a thulium doped fiber amplifier using three simultaneous different pumping wavelengths. We obtained more than 30 dB peak gain in the S band region.

Double pass erbium doped fiber amplifier with an embedded DCF module for L band DWDM applications

We present gain, noise figure and 10 Gbit/s BER characterization of an 8 channels L band DWDM system which uses a double pass erbium doped fiber amplifier incorporating a DCF module for chromatic dispersion compensation

An EDFA hybrid gain control technique for extended input power and dynamic gain ranges with suppressed transients

A new approach for a hybrid gain control scheme based on an improved overlap of the all-optical and electrical feedforward gain control techniques for a single EDFA is presented. A wide input power operation range and a multi-level dynamic gain range are possible, enabling efficient gain control performance and allowing EDFA operation as pre, in line or booster amplifier. An EDFA characterization during add and drop of 1, 3, 7, 15, and 31 out of 32 input channels is also presented. The results show a maximum 0.6 dB deviation from the set EDFA gain value. By considering the EDFA response time, the interaction between optical and electrical controls shows a drastic reduction on EDFA transient impact to less than 2 ms with maximum overshoot/undershoot lower than 0.7 dB.

Project GIGA-high-speed experimental IP/WDM network

This paper describes Project GIGA-high-speed Experimental Network, a multiinstitutional, multidisciplinary, national project funded by the Brazilian government. The main goal of Project GIGA is to promote research, development and experimentation of technology at all layers, aiming at generating knowledge, products and services that will make it possible for Brazilian individuals and companies to play a role in the converged telecom sector. The project centres on the high-speed Network Testbed, a platform for experimentation and validation of technology, equipment, protocols, services and applications, whether they be developed in the project or not. The paper explains the objectives, the expected impact and the organisation of the project. It also describes the architecture of the network testbed, the ongoing research and development activities and some of the results obtained.

Double pass L band erbium doped fiber amplifier with an embedded DCF

We present gain, noise figure and 10 Gbit/s BER characterization of a double pass L band erbium doped fiber amplifier that incorporate a DCF module for chromatic dispersion compensation.

Effective penalty reduction in an L-Band WDM system using hybrid amplifier with a dispersion-compensating module

We demonstrate the combined use of a single laser diode and a fiber ring laser for pumping a Raman-amplified dispersion compensating fiber (DCF) to upgrade an L-Band WDM transmission system at 10 Gbit/s. The broadband DCF module is placed at the output of an L-Band Erbium-doped fiber pre-amplifier, to reduce the power penalties associated to chromatic dispersion. The hybrid DCF-Raman amplifier, provided by two pump-wavelengths originated from a single pump source, permits the L-band channel allocation with efficient transmission performance through a metro-scaled (100 km) standard single mode fiber (SSMF). The performance of eight WDM channels in the L-Band is presented with nearly penalty free operation at 10 Gbit/s, which are corroborated by numerical simulation analysis. The residual power penalties obtained were either close to 1 dB or less for all channels in the L-band. The L-band hybrid pre-amplifier, composed by a single-stage EDFA and a Raman-pumped DCF module, is proposed as an alternative solution for the capacity upgrade of metropolitan WDM transmission systems.

Q-factor penalty evaluation in a cascade of all-, optical nodes using a re-circulating loop

The impact of all-optical node concatenation effects on the performance of a WDM transmission through 350 km of standard fiber is investigated with re-circulating loop experiments. A node of the OMEGA test bed is used to simulate a chain of fourteen nodes. Each link comprises a combination between one node (mux/demux, thermal optical switch and erbium-doped fiber optical amplifier) and 25 km of standard single mode fiber. Amplifier noise accumulation has been found to be the most detrimental effect.

Experimental demonstration and numerical simulations of 16/spl times/10 Gb/s DWDM repeaterless transmission systems with residual dispersion

Presents results of experimental demonstration and numerical simulations of a DWDM system with 16 channels at 10 Gb/s transmitted over 112 km and 73 km of standard singlemode fiber. The dispersion for all the channels at the end of the fiber link is undercompensated. The residual dispersion is 521 ps/nm for the 112 km link and 324 ps/nm for the 73 km link at 1550 nm. The power penalties obtained both in the numerical simulations and in the experimental demonstration are presented for both cases.