Mohammed Y. S. Sowailem

400-G Single Carrier 500-km Transmission With an InP Dual Polarization IQ Modulator

In this letter, we demonstrate experimentally 400-G transmission over 500 km using an InP-based dual-polarization IQ modulator on a single wavelength. The results show that a 56-Gbaud polarization division multiplexed (PDM)-16-quadratic-amplitude modulation (QAM) modulated signal can be transmitted over 500 km at a bit error rate (BER) below the hard decision forward error correcting threshold of 3.8 ×10-3. A 43-Gbaud PDM-64-QAM modulated signal can be transmitted over 320 km with a BER below the soft decision forward error correcting threshold of 2×10-2.

100G and 200G single carrier transmission over 2880 and 320 km using an InP IQ modulator and Stokes vector receiver.

We demonstrate experimentally the transmission of single carrier 56 Gbaud 16-QAM, 8-QAM and QPSK optically modulated signals over 320, 960 and 2,880 km, respectively, using a fully packaged InP IQ modulator and a Stokes vector direct detection (SV-DD) receiver realized using discrete optics. Results show that by optimizing the carrier-to-signal-power ratio, the total throughput-times-distance product for 16 QAM and QPSK are 71,680 Gbps.km and 322,560 Gbps.km, respectively, at bit error rate (BER) below the hard decision forward error correcting threshold (HD-FEC) of 4.5 × 10-3.

Implementation of optical burst switching in data centers

We demonstrate the implementation and performance of optical burst switching in data centers. We propose the use of hybrid burst assembly algorithm and compare both the first-fit and horizon scheduling algorithms in a fat-tree topology.

770-Gb/s PDM-32QAM Coherent Transmission Using InP Dual Polarization IQ Modulator

We experimentally demonstrate 770-Gb/s (77-Gbd PDM-32QAM) transmission on a single wavelength using an indium phosphide dual polarization IQ modulator over 320 km of standard single mode fiber, which is suitable for low-cost metro networks and datacenter interconnects. Moreover with the same setup, we also demonstrate transmissions of 84-Gbd polarization division multiplexed (PDM)-16QAM and 84-Gbd PDM-8QAM signals over 960 and 1980 km distances, respectively, for regional and long-haul networks.

Single wavelength 480 Gb/s direct detection over 80km SSMF enabled by Stokes vector Kramers Kronig transceiver

We propose 4D modulation with directed detection employing a novel Stokes-Vector Kramers-Kronig transceiver. It shows that employing Stokes vector receiver, transmitted digital carrier and Kramers-Kronig detection offers an effective way to de-rotate polarization multiplexed complex double side band signal without using a local oscillator at receiver. The impact of system parameters and configurations including carrier-to-signal-power ratio, guard band of the digital carrier, oversampling ratio and real MIMO is experimentally investigated. Finally, a record 480 Gb/s data rate over 80 km SSMF is achieved in a 60 Gbaud PDM-16QAM single carrier experiment with a BER below the threshold of 2.0x10-2

Transmission of 344 Gb/s 16-QAM Using a Simplified Coherent Receiver Based on Single-Ended Detection

We demonstrate a single-wavelength, 344-Gb/s, 43-Gb 16-quadrature amplitude modulation (QAM) polarization division multiplexed signal transmission over 800 km operating below the hard-decision forward error correction (FEC) BER threshold of 3.8 × 10-3 using an InP dual-polarization in-phase/quadrature modulator. At the receiver, a simplified single-ended coherent receiver with novel digital signal processing (DSP) for self-beating noise removal is employed. Compared with the conventional single-ended detection, this signal processing method doubles the propagation distance and increases the SNR by more than 1 dB. In addition, this DSP method provides 10 dB of the received optical power dynamic range while operating below the hard-FEC BER threshold of 3.8 × 10-3, compared with the no dynamic range for a single-ended receiver without the proposed DSP.

Performance analysis of a core node equipped with wavelength converter pool in an Optical Burst Switched network

A performance analysis of a core node in an OBS network having wavelength converters in the node resources is presented. The analysis assumes that the wavelength converters are deployed at the input ports of the node such that the node may have variable wavelength conversion capability. This means that the node may have no, partial or full conversion capability. The no and partial wavelength conversion is imitated by modeling each output port in the node as an M/M/w/w queue with limited server accessibility. Two performance measures are derived from the model; namely, the steady state throughput and the average burst loss probability assuming Poisson traffic arrivals. In addition, a simulation work is performed in order to validate the results of our proposed model. After taking into consideration the cost of the wavelength converters, optimum values for the wavelength conversion capability in the node, which lead to minimum burst loss probability, are reached for different traffic conditions.

Equalization-Enhanced Phase Noise in Stokes-Vector Direct Detection Systems

In this work, we provide both numerical and experimental investigations of equalization-enhanced phase noise (EEPN) in Stokes-vector direct detection (SV-DD) systems. We show that the influence of EEPN cannot be neglected in high symbol rate SV-DD systems after transmission over several hundred kilometers of fibers when electronic chromatic dispersion compensation and lasers with linewidths of the order of Megahertz are employed. Simulation results are presented to evaluate the dependence of EEPN effects on laser linewidth, transmission distance, and symbol rate. Experiments are then conducted in a 56-Gbaud 16-quadrature amplitude modulation (QAM) SV-DD system to demonstrate the EEPN-induced performance degradation after 320-km transmission over standard single mode fiber (SSMF).

Enhanced Channel Equalizers for Adaptive Zero-Guard-Interval CO-OFDM Systems

We propose the design and implementation of frequency domain block least mean square and block recursive least square equalizers for adaptive zero-guard-interval (ZGI) coherent optical (CO) orthogonal frequency division multiplexing (OFDM) systems. We experimentally demonstrate the improvements in fiber nonlinear tolerance and channel estimation accuracy over conventional training symbol (TS)-based equalizers and data aided zero-forcing (ZF) equalizers, in single channel 112-Gb/s quadrature phase shift keying (QPSK), and 250-Gb/s 16 quadrature amplitude modulation (QAM) ZGI CO-OFDM systems. The transmission distance is increased by 20% and 7% for QPSK, and 53% and 35% for 16-QAM systems, compared with the TS-based and decision aided ZF adaptive equalizers, respectively. In addition, simulation results demonstrate the improved temporal tracking ability of the proposed algorithms over the previous ZF equalizer.

Contention resolution strategy in optical burst switched datacenters

We propose using burst assembly electronic buffers at source pod in optical burst switched datacenters for contention resolution. 100% throughput is approached with latency in the order of microseconds without any buffering in core switches.