Michel W. Chbat

Investigation of cross-phase modulation limitation over various types of fiber infrastructures

The impact of cross-phase modulation (XPM) on the transmission performance of a 2/spl times/10 Gb/s multiplex is characterized. In contrast to the other investigated fiber schemes, dispersion-compensated single-mode fiber is virtually not affected by XPM down to 50-GHz channel spacing.

Optical clock recovery from a data stream of an arbitrary bit rate by use of stimulated Brillouin scattering

Using a fiber-optic stimulated-Brillouin-scattering amplifier as an active filter, we have demonstrated optical clock recovery from 5-Gbit/s return-to-zero-format optical data. Definite patterns and pseudorandom bit sequences were tested. This scheme requires no prior knowledge of the clock frequency and is well suited for operation at higher data rates.

Performance characterization of a harmonically mode-locked erbium fiber ring laser

We describe the performance of a harmonically mode-locked, erbium fiber ring laser. Transform-limited pulses with durations of 20-50 ps at 5.044 GHz repetition rate are obtained. The modulation frequency can be detuned by up to /spl plusmn/70 kHz and the lasing wavelength can be varied over the entire erbium gain bandwidth. Pulsewidths and pulse bandwidths are measured as a function of modulation power and frequency detuning. The laser is actively stabilized by locking intra-cavity Fabry-Perot etalon passbands to the laser modes.<<ETX>>

Key building blocks for high-capacity WDM photonic transport networks

The objective of this paper is to give an overview of the different studies we have performed at the research level regarding the design and implementation of a photonic wavelength division multiplexing (WDM) layer providing transparent transport services to client layers (SONET/SDH, ATM, etc.). Such a network requires a number of enabling factors to be assessed in order to become a reality. Among these factors are the availability of high-capacity WDM transmission systems and efficient optical routing nodes based on mature technology, the design of robust networks optimizing the utilization of resources, and the development of a management system in accordance with presently applied standards for transport networks. We review our achievements in these different fields.

High-spectral-efficiency transmission systems

Spectrally-efficient transmission techniques provide the capability for higher channel density in WDM systems and, in some cases, allow the extension of the transmission distance limited by physical fiber impairments, such as chromatic dispersion and polarization mode dispersion. We review the main techniques and evaluate the potential of their implementation in dense WDM systems.

All-optical 1.5 μm to 1.3 μm wavelength conversion in a walk-off compensating nonlinear optical loop mirror

We demonstrate highly efficient all-optical conversion from 1.5 /spl mu/m to 1.3 /spl mu/m using a novel nonlinear optical loop mirror that compensates for walk-off. We make the fiber loop by splicing alternating segments of standard single-mode and dispersion-shifted fibers and choose their lengths such that the walk-off of the 1.3 /spl mu/m and 1.5 /spl mu/m pulses in one segment is completely reversed in the adjacent segment. We also show that the width of the converted pulses can be tailored by this scheme.<<ETX>>

Long-haul WDM NRZ transmission at 10.7 Gb/s in S-band using cascade of lumped Raman amplifiers

We demonstrate the first S-band long-haul WDM transmission using a cascade of dispersion compensating lumped Raman amplifiers. Twenty NRZ channels, spanning the entire S-band, were transmitted over 10 spans of standard single-mode fiber (SSMF) (867 km) at 10.67 Gb/s, each achieving BER<10/sup -12/ without FEC.

Operation of a nonlinear optical loop mirror with orthogonally polarized waves in nonpolarization-preserving, single-mode fiber

We demonstrate stable operation of a NOLM using orthogonally polarized control and signal beams in nonpolarization-preserving, single-mode fiber. The NOLM can transcribe data from an optically incoherent input at one wavelength to a coherent output over a range of wavelengths. Operation of the NOLM without tuning for the input bit rate is possible over a range of bit rates from less than 1 Gb/s to more than 50 Gb/s.

Interactions of bound multiple solitons in strongly birefringent fibers

We report the observation of the interaction of bound multiple solitons generated by orthogonally polarized, highamplitude pulses in strongly birefringent fibers. For the birefringence used, the threshold amplitude for the interaction is higher than that of the onset of second-order solitons on each axis. The characteristics of the output pulses are in good agreement with the results of a numerical simulation of this interaction. A general investigation of this effect is carried out at high values of birefringence, and it is found numerically that, even though the system is nonintegrable, the description of its evolution appears to be reduceable to a finite number of effective degrees of freedom.

Raman amplifiers for new wavelength bands

Summary from only given. Raman amplifiers now constitute a viable solution for long-haul and/or ultra-long-haul, large throughput WDM systems. The main benefit is low-noise, wide-band amplification over any spectral window within the low-loss region of optical fibers. Several transmission experiments have been reported illustrating these benefits. In addition,all Raman transmission experiments have been reported, resulting in very high performance with a high WDM density and a large transmission distance.