Uri Mahlab

Stimulated Brillouin scattering based in-band OSNR monitoring technique for 40 Gbps and 100 Gbps optical transparent networks

We demonstrate experimentally and numerically that the SBS based in-band OSNR monitoring technique can be used for dual polarization signals. We also present novel approach for a drastic enhancement of the sensitivity monitoring range by intentionally adding in-band ASE noise into the signal. Numerical results are provided for 44.6 Gbps DPSK, 44.6 Gbps DQPSK and 112 Gbps Dual Polarization (DP-) QPSK signals, with both 100 GHz and 50 GHz channel spacing scenarios.

New method for developing optical code division multiplexed access sequences using genetic algorithm

A new method for developing optical code division multi- plexed access (CDMA) address code sequences is presented. The method is based on the genetic algorithm, which has already shown success in developing two-dimensional correlation functions for pattern recognition. The algorithm is very flexible in its optimization criteria and is thus adequate for various optical CDMA applications, including coherent and noncoherent systems. Preliminary computer experimental results are presented that indicate very good discrimination ratios and very fast convergence of the search process. Important implications include synchronization-independent CDMA system design, reduction in optical beat noise, optical power budget improvement, and enhanced security.

Optical Transmission of OFDM Ultra-wideband Signals beyond 40 Gb/s (Invited Paper)

We for the fi rst time propose the highly eff icient method of RF and optical signal mixing based on two different architectures: the parallel-RF/serial-optics architecture charac- terized by all-optical mixing for sub-carrier multiplexing, and the parallel-RF/parallel-optics architecture based on the array of 12x10 GHz components with directly modulated VCSELs and 12 multimode optical fibers. The main advantages of the both architectures are simplicity and low-cost implementation. We have carried out numerical simulations of ultra-wideband signals propagation in the proposed systems and proved the high efficiency and feasibility of the proposed method.

A new method for developing optical CDMA address code sequences using the genetic algorithm

A new method for developing optical CDMA address code sequences is presented. The method is based on the genetic algorithm, which has already shown success in developing two-dimensional correlation functions for pattern recognition applications. The algorithm is very flexible in terms of optimization criteria, thus adequate for various optical CDMA applications, including coherent and non-coherent systems. Preliminary computer experimental results are presented, indicating very good discrimination ratios, and very fast convergence of the search process. Important implications include synchronization-independent CDMA system design, optical beat noise reduction, optical power budget improvement, and enhanced security.

In-band optical signal-to-noise ratio monitoring technique based on Brillouin fiber ring laser

We propose an improved technique for in-band optical signal-to-noise ratio (OSNR) monitoring based on a Brillouin fiber ring laser seeded by the optical channel to be monitored. This technique shows a reduction of the required input power into the monitor along with a large and tunable dynamic OSNR monitoring range. It is demonstrated experimentally and numerically for various bit rates and modulation formats.

Identification of linear and nonlinear propagation regimes in an optical fiber link using chaos analysis

We propose and demonstrate a novel approach to identify linear and nonlinear propagation regimes of an optical signal in an opti- cal fiber link by using chaos analysis. We show that the chaotic charac- teristics of a propagating optical signal are affected by both the chro- matic dispersion and the nonlinear effects in the optical fiber. Linear or nonlinear behavior is detected by determining the maximum Lyapunov exponent of the signal and the use of the recurrence plot technique. An experimental demonstration is performed using 10-Gbps signal propaga- tion in a 100-km fiber link with different launched optical powers. Chaos analysis shows a clear identification of the linear and nonlinear optical propagation regimes by using a classification scheme based on a multilayer neural network. Numerical simulations confirm the experimen-

Novel all-optical quaternary amplitude shift keying modulation technique based on cross-gain modulation in a semiconductor optical amplifier

We present a novel all-optical quaternary shift keying 4-ASK modulation technique based on the cross-gain modulation in a semicon- ductor optical amplifier SOA of a modulated probe with moderate ex- tinction ratio. Experimental demonstrations are presented for 20-Gb/s non return to zero NRZ and return to zero RZ 4-ASK signals with different level distributions and extinction ratios. The dispersion tolerance limitations are investigated. RZ 4-ASK signals show better dispersion robustness with accumulated dispersion range from x7f240 to 350 ps/nm than NRZ 4-ASK signals due to their reduced fre- quency chirp.

In-Band OSNR System Margin and Overall Link Impairment Level Monitoring Techniques Using an Optical Coherent Receiver

We propose a novel and in-service method for in-band OSNR system margin and overall link impairment level monitoring based on the use of an optical coherent receiver. This technique relies on the estimation of the ESNR margin of the received optical coherent channel, scaled by a correction factor which depends on the modulation format and the overall link impairment level. This method is demonstrated experimentally for a 120 Gb/s DP-QPSK channel in both dispersion and nondispersion managed links with different impairment scenarios.

OSNR system margin monitoring technique for coherent transparent optical networks

We propose a novel approach for transparent and in-service OSNR system margin monitoring for coherent optical modulation formats. This technique is demonstrated experimentally for a 120.6 Gb/s DP-QPSK channel in both dispersion and non-dispersion managed links.

Dispersion compensation of self phase modulation impairment in optical channel using MLSE

In high power optical channels self phase modulation (SPM) imposes spectral broadening distortions. Consequently, ldquoover samplingrdquo beyond the bitrate is proposed according to Nyquist theorem. Here received signal ldquoover samplingrdquo together with maximum likelihood sequence equalizer is demonstrated, indicating of significant enhancement of inter-symbol-interference mitigation in highly non-linearly distorted channel by SPM.