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There are several factors that can contribute to increase of the total information capacity of free space optical (FSO) channels and they include parallelism in design of system architecture with a multitude of independent modes (both in spectra and spatial domains), selection of modulation, detection, and coding strategies, as well as employment of compensation schemes that can offset the impact...
In this paper, a novel multidimensional optical OFDM system is investigated for programmable transceivers, saving DSP resources and facilitating scalability at the increase of the number of dimensions. Numerical evaluations show successful 100 Gb/s transmission for different link configurations.
Our aim in this work is to characterize experimentally the transmission properties of a 19-core plastic optical fiber and to compare them to those obtained for several single-core POFs under the same conditions. Thus, we measured frequency response, attenuation and angular output power distribution as functions of fiber length under different configurations. Additionally, measurements of parameters...
We proposed a fast all-optical regenerative memory loop which can be used for pulse amplitude modulation (PAM). The ultra-fast all-optical memory loop is based on the Mach-Zehnder interferometer (MZI) with quantum dot (QD) semiconductor optical amplifier (SOA) in each arm. It can operate at bit rates up to 100 Gb/s due to the fast gain recovery typical for QD-SOA. We have carried out the numerical...
The development of reconfigurable and high throughput architectures is the utmost target for researchers in the field of Radio over Fiber (RoF). In this paper, we developed a cognitive radio over fiber system lined up with Software Defined Networking owing to improve the quality of transport using a pre-equalization technique. The pre-equalization technique is based on Least Mean Square (LMS) algorithm...
Free Space Optics (FSO) is rapidly gaining interest as a line-of sight communication technology that offers capabilities similar - in terms of bandwidth and transfer rates - to optical fibre, also possessing several advantages compared with traditional radio frequency links. However, FSO link quality can be strongly affected by unfavourable weather conditions and also by the phenomenon of optical...
This paper summarizes recent work on a hierarchical ring-based network architecture (Hi-Ring) for datacentre and short-range applications. The architecture allows leveraging benefits of optical switching technologies while maintaining a high level of connection granularity. We discuss results of optical switching in the various physical dimensions incorporated in the hierarchical nodes and we discuss...
Network coding has been proven to be an effective approach towards achieving the network capacity and resources efficiency. However, most of the work achieved has been under the umbrella of wireless networks. In this paper we investigate the use of network coding to improve energy efficiency of the IP/WDM optical core considering unicast traffic flows by implementing coding at the optical layer of...
Much effort has been devoted to the study of glasses that contain the chalcogen elements (sulfur, selenium and tellurium) for photonics' applications out to MIR wavelengths. In this paper we describe some techniques for determining the refractive index dispersion characteristics of these glasses. Knowledge of material dispersion is critical in delivering step-index fibres including with high numerical...
A tandem dual electrode Mach Zehnder modulator (DE-MZM) generated W-band optical code division multiple access (OCDMA) radio-over-fiber (ROF) system is proposed and the simulation results are presented. We have investigated a method to upconvert a baseband laser signal to the millimeter wave band (W-band in this case) by utilizing two cascaded DE-MZMs driven by lower frequency sine-wave generators...
In ultra-high speed incoherent optical communication systems chromatic dispersion is considered a key impairment. Tuneable dispersion compensation for the signal data ultra-short carrier pulses propagated through the fibre optic cable is an effective way of overcoming this problem. The transmission system performance could be improved by manipulating the inbound pulses through the chirp control by...
We propose unequal sideband intensity based modulation scheme called vestigial sideband scheme (VSB) for the radio over fiber system (RoF) using concatenated Mach-Zehnder modulator (MZM) and phase modulator (PM). This scheme can be generated with proper adjustment of the modulation indexes of the modulators. MZM-PM configuration can also be used for generating single sideband (SSB) and carrier suppressed...
We propose all optical virtual private network (VPN) using microwave photonic filter for the first time in orthogonal frequency-division multiple based passive optical network (OFDM-PON). In our scheme, optical resonator is used at optical line terminal (OLT) as a subsystem to design photonic bandpass filter (P-BPF). This filter has free spectral range (FSR) corresponding to resonator length. Using...
Passive optical network FTTH is the best option to guarantee ultra-broadband access and satisfy future-proof user demands. NG-PON2 standardization does not yet consider in a conclusive way the possibility of sharing the same PON among different operators in order to make the network economically sustainable. The Italian research project ROAD-NGN is filling the gap by studying various advanced PON...
We show here that combination of “low-cost” transport solutions based on 100 Gbps DCO-CFP interface and G.657.A2 fibre is able to address long-haul (∼2000 km) WDM transmission applications. A performance comparison is carried out with “premium” solutions based on 100 Gbps coherent OIF-MSA transceivers and legacy G.652.D fibre.
Fibre to the Home (FTTH) is currently the best solution to meet the requirements of the Digital Europe Agenda within the Europe 2020 strategy, concerning with the increase of the high speed access usage among the European citizens. Nevertheless, the roll-out of FTTH has high costs for the deployment of the optical fibres and the equipment that limit the investments from the operators. Therefore, the...
Next-generation access networks (NGANs) mainly include wavelength division multiplexing (WDM) based 60GHz Radio over Fibre systems (60G-RoF) and WDM Passive Optical Networks (WDM-PONs). Semiconductor optical amplifier may be the key device of colorless unit in these WDM based systems. The device can be effectively utilized as external modulator because it can perform simultaneously amplification and...
In this contribution a multiwavelength erbium ring laser is presented. The multiwavelength operation isachievedby using a novel in-line Mach-Zehnder (MZ) fibre interferometer based on multicore microstructured fibre (MC-MOF).The MZ interferometer acts as a periodic spectral filter. The modal properties of the MC-MOF are analysed using the finite difference method. Dual wavelength operation is demonstrated...
We report on the inscription of Bragg gratings in a bioresorbable phosphate optical fiber using 193 nm excimer laser radiation and the phase mask technique. Bragg gratings with a typical 6 dB transmission strength were created over a length of 5 mm employing moderate inscription energy densities. The dissolution of the fiber, when immersed in phosphate buffered saline (PBS) solution, was studied through...
In this paper, we propose a novel method to experimentally determine the linear absorption coefficient (LAC) of graphene-silicon hybrid waveguides (GSHWs) by a symmetrical add-drop silicon microring resonator. Experimental results show that the LAC of a GSHW has an average value of 0.23 dB/µm. Our approach does not depend on the fiber coupling, waveguide end facets etc. and thus, is promising for...
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