S. Bigo

Two mode transmission at 2x100Gb/s, over 40km-long prototype few-mode fiber, using LCOS-based programmable mode multiplexer and demultiplexer

We present a novel optical transmission system to experimentally demonstrate the possibility of mode division multiplexing. Its key components are mode multiplexer and demultiplexer based on a programmable liquid crystal on silicon panel, a prototype few-mode fiber, and a 4×4 multiple input multiple output algorithm processing the information of two polarization diversity coherent receivers. Using this system, we transmit two 100 Gb/s PDM-QPSK data streams modulated on two different modes of the prototype few-mode fiber. After 40 km, we obtain Q(2)-factors about 1 dB above the limit for forward error correction.

Mode-Division Multiplexing of 2

We demonstrate one of the first experiments of optical transmission based on mode-division multiplexing over a few-mode optical fiber. The mode multiplexer and demultiplexer are based on a programmable liquid crystal on silicon panel. Using this system, we transmit two 100 Gb/s polarization division multiplexed quaternary phase-shift keying data streams modulated on two different modes of the prototype few-mode fiber. At the receiver, a set of optical coherent detectors with DSP including multiple-input multiple-output algorithms recover the signal and permit to mitigate the crosstalk stemming from imperfect mode conversion.

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We transmit two 100Gb/s PDM-QPSK data streams over two different modes of a 40km-long prototype few-mode fiber. Our experiment is performed with an LCOS-based mode multiplexer/demultiplexer and 4×4 MIMO algorithm in a coherent receiver.

100 Gb/s Channels Using an LCOS-Based Spatial Modulator

A record capacity distance product of 41.8 Petabit/s middotkm is demonstrated. A total of 164 channels are modulated at 100 Gbit/s with PDM-QPSK format, packed with 2 bit/s/Hz information spectral density and recovered by off-line processing in a coherent receiver after 2550 km distance.

Transmission at 2×100Gb/s, over two modes of 40km-long prototype few-mode fiber, using LCOS-based mode multiplexer and demultiplexer

Ultrafast all-optical signal processing techniques are expected to play a major role in future ultrafast single-carrier soliton systems, because they remove the electronics bottleneck. In this paper, two all-optical devices, the nonlinear optical loop mirror (NOLM) and the Kerr fiber modulator (KFM), are used to achieve major functions related to high bit rate soliton links. At the interface with existing networks, conversions from data at the nonreturn-to-zero (NRZ) format to return-to-zero (RZ) and soliton data, and vice-versa are required. These two conversions are demonstrated through NOLMs, and their limitations investigated. However, the main part of this paper is devoted to in-line soliton regeneration through synchronous modulation. Synchronous modulation requires both clock recovery and in-line optical modulation. In the following, all-optical approaches for these two functions are considered separately, before being associated in a true all-optical regenerator. All-optical clock recovery techniques are first reviewed. An experimental implementation of one of these techniques is described. On the other hand, all-optical modulation can be done either with intensity or phase modulators. We initially proposed the NOLM as all-optical intensity modulator. We analyze it theoretically, both from the component and the system application viewpoints. A modified configuration of the NOLM, having two optical controls, removes some limitations pertaining to the single-control configuration, yielding even higher performance. The other all-optical synchronous modulator considered here is the KFM, which is a pure phase modulator. Its potential is demonstrated in a 20-Gb/s soliton transmission experiment, when driven by an optoelectronic optical clock generation device. Issues specific to the implementation of both types of all-optical fiber-based modulators are discussed. Finally, a true all-optical synchronous regenerator, combining all-optical clock recovery circuit and KFM, is tested in an actual soliton transmission experiment at 20 Gb/s.

Transmission of 16.4-bit/s Capacity Over 2550 km Using PDM QPSK Modulation Format and Coherent Receiver

We demonstrate the transmission of 256 polarization-division and wavelength-division multiplexed channels at 42.7 Gbit/s rate over 100 km of TeraLight/sup TM/ fiber. An overall capacity of 10 Tbit/s is achieved in C and L bands at a record 1.28 bit/s/Hz spectral efficiency.

All-optical fiber signal processing and regeneration for soliton communications

We investigate via experiments and simulations the statistical properties and the accumulation of nonlinear transmission impairments in coherent systems without optical dispersion compensation. We experimentally show that signal distortion due to Kerr nonlinearity can be modeled as additive Gaussian noise, and we demonstrate that its variance has a supra-linear dependence on propagation distance for 100 Gb/s transmissions over both low dispersion and standard single mode fiber. We propose a simple empirical model to account for linear and nonlinear noise accumulation, and to predict system performance for a wide range of distances, signal powers and optical noise levels.

10.2 Tbit/s (256x42.7 Gbit/s PDM/WDM) transmission over 100 km TeraLight/sup TM/ fiber with 1.28 bit/s/Hz spectral efficiency

We measure the impact of stimulated Raman scattering on the power distribution of a 32-channel multiplex after 100-km transmission over various fiber types. The Raman gain coefficient is then estimated in each configuration.

On nonlinear distortions of highly dispersive optical coherent systems

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.

Experimental investigation of stimulated Raman scattering limitation on WDM transmission over various types of fiber infrastructures

We demonstrate the interconnection of two optical packet switching systems: a hybrid optoelectronic packet router and two optical packet rings. Error-free inter-ring and intra-ring optical packet transmission and unicast and multicast transport of encapsulated 10 GbE are achieved.