Bruno Lavigne

Optical regeneration at 40 Gb/s and beyond

As optical amplifiers have opened new perspectives for optical communication systems with ultrahigh capacities and long-haul transmission distances (more than 1 Tb/s over 10 000 km), fundamental limits are being felt. In order to overcome these propagation impairments, another technology revolution is soon required. Promising developments concern in-line all-optical regeneration, which makes it possible to transmit optical data over virtually unlimited distances. In this paper, we recall the basic principles of optical regeneration in optical communication systems and review the current technology alternatives foreseen for future 40-Gb/s transmission system implementation, as investigated in Alcatel Research and Innovation. The alternative offered by optoelectronic regeneration is also discussed, so as to identify and highlight the advantages of the all-optical approach.

Physical and logical validation of a network based on all-optical packet switching systems

The large growth of telecommunication traffic demand generated by multiple new applications and expected to last at least for the next decade will force telecom operators to consider offering more flexible transport services. All-optical packet switching is a powerful technique to provide this flexibility and to support in a cost-efficient way a wide range of bandwidth consuming applications. After a very brief introduction about the packet-switched network architecture studied in the framework of the ACTS KEOPS project, we describe the structure of the packet-switching node we have defined. We then move into physical and logical analysis of the network including more than 40 network sections based on 160 Gb/s throughput optical packet switching nodes could operate error free. In addition, logical simulations have proved that such networks could provide a quality of service (packet loss rate and packet transfer delay per node) compatible with a large variety of service classes. Both results validate the feasibility of the network concept and pace the way toward a flexible network based on all-optical switching techniques.

Study of phase-noise properties and timing jitter of 40-GHz all-optical clock recovery using self-pulsating semiconductor lasers

This paper reports on timing-jitter analysis of an all-optical clock-recovery scheme at 40 GHz using self-pulsating (SP) lasers. Based on the analogy with injection locking of oscillators, theoretical investigations on phase-noise properties of the recovered clock lead to the demonstration of a filtering function with slope that is compliant with the International Telecommunications Union (ITU) standards and allow us to underline the dependence of the cutoff frequency of the filtering transfer function on the spectral linewidth of the free running SP laser. From this phase-noise analysis, an analytical expression of the timing jitter of the recovered clock is derived, including the optical signal-to-noise ratio (OSNR) of the injected signal. A set of experiments on all-optical clock recovery at 40 GHz is then presented and demonstrates the crucial role of the spectral linewidth on the timing-jitter-filtering function of the SP laser. In good agreement with theoretical results, the impact of the OSNR degradation of the injected signal on the timing jitter is also demonstrated. Finally, the all-optical clock-recovery operation using a quantum-dot SP laser is shown to be standard compliant in terms of timing jitter, even for highly degraded OSNR

Standard-compliant jitter transfer function of all-optical clock recovery at 40 GHz based on a quantum-dot self-pulsating semiconductor laser

This letter reports on all-optical clock recovery over 40-Gb/s signal using a quantum-dot (QD)-based self-pulsating (SP) laser. In particular, the jitter transfer function from the input signal to the recovered clock is measured for the first time. We clearly demonstrate that, thanks to the narrow spectral linewidth of the free-running SP signal, the QD-based laser allows the suppression of high frequency jitter, and the cutoff frequency is exactly that required by the ITU-T recommendation G825.1 at 40 GHz

SOA-based devices for all-optical signal processing

Development of all-optical and wavelength domain multiplexing (WDM) networks requires numerous and diversified optical processing functions like wavelength conversion, regeneration, add&drop, time domain multiplexing or logic functions. A fast all-optical signal processing functions realized with nonlinear semiconductor optical amplifiers, particularly those associated to interferometric structures, are presented. Different integration schemes are compared with criteria concerning device insertion in systems. SOA-MZI assembles the interests of the technology simplicity and maturity, the design modularity and the use simplicity including standard mode 40 Gb/s operation.

Cascade of 100 optical 3R regenerators at 40 Gbit/s based on all-active Mach Zehnder interferometers

The operation of an optical 3R regenerator combining monolithic integrated semiconductor optical amplifier-based Mach Zehnder interferometers is demonstrated at 40 Gbit/s. 100 regenerators have been cascaded in a recirculation loop including 40 km of dispersion shifted fibre.

Polarization-Insensitive Low Timing Jitter and Highly Optical Noise Tolerant All-Optical 40-GHz Clock Recovery Using a Bulk and a Quantum-Dots-Based Self-Pulsating Laser Cascade

We report on the experimental assessment of an all-optical clock-recovery scheme at 40-Gb/s cascading a polarization-insensitive bulk-based self-pulsating (SP) laser and a high spectral purity quantum-dots-based SP laser. It is demonstrated experimentally that such a clock-recovery scheme is polarization insensitive, efficient in the jitter filtering, and tolerant for an input optical signal-to-noise ratio (OSNR) as low as 15 dB/0.1 nm. It is shown theoretically that the jitter-filtering function of the cascade is the product of the transfer functions of both lasers. The contributions of the phase noise of these two lasers to the final jitter are also identified and quantified. The influence of the degradation of the OSNR to the total timing jitter is also analyzed. The approach proposed in this paper offers the real opportunity to realize an all-optical clock recovery with a performance compatible for system applications

Performance comparison of 40G and 100G coherent PDM-QPSK for upgrading dispersion managed legacy systems

We compare the performance of 40 G and 100 G coherent PDM-QPSK solutions for the upgrade of existing 10 G-based optical networks. This comparison is performed on the Alcatel-Lucent 1626LM commercial system.

Improvement of regeneration capabilities in semiconductor optical amplifier-based 3R regenerator

A 4-dB reduction of the optical signal-to-noise ratio admissible by an all-optical regenerator is demonstrated. Applied to long-haul transmission, an error-free 10-Gbit/s NRZ transmission over 170,000 is performed with 170-km repeater spacing.

Experimental validation of an all-optical network based on 160 Gbit/s throughput packet switching nodes

We present for the first time a physical validation of an all-optical packet-switched network. More than 40 network sections, including 100 km of fibre and one optical packet switching node, have been cascaded with negligible sensitivity penalty at 10 Gbit/s.