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The statistics of ldquoequivalentrdquo differential phase (EDP) of differential quadrature phase-shift keying (DQPSK) systems is assessed numerically. It is shown that the EDP statistics is approximately Gaussian for a large range of system parameters. Thus, performance evaluation methods based on a Gaussian approximation for the EDP may be used. However, both the mean and variance of the Gaussian...
Key issues related to the design of electro-optic transmitters and receivers are discussed in this paper. These topics include limitations in 100G transmission systems resulting from the frequency response of devices and non-linear effects. Numerical simulations illustrate the importance of realistic modeling in such high-speed systems.
Result of numerical simulations are presented on transmission limits for different modulation formats at 100 Gb/s caused by non-linear effect and chromatic dispersion in standard and non-zero dispersion shifted single mode fibres. Different modulations formats are simulated and their properties compared.
The versatile transceiver in study for the Super Large Hadron Collider (SLHC) will have to endure severe radiation and temperature conditions while providing a high speed digital communication link to cover the experiment requirements. For this, characterization and model analysis of the electro-optic components (in particular the semiconductor laser), is of utmost importance as it will enable the...
Optical technology allows to design an inter-satellite network able to guarantee the data transfer between different places on Earth, at high data rate. Proposed optical network is composed by 27 Medium Earth Orbit (MEO) satellites as network nodes, distributed over three different orbits; communication is established at an access node and reaches the destination node through a number of hops on intra-orbit...
We propose a bidirectional reflective semiconductor optical amplifier (RSOA) based wavelength-division-multiplexing passive optical network (WDM-PON) utilizing a differential phase shift keying (DPSK) signal for down-link and an on-off keying (OOK) signal re-modulated for up-link with high extinction-ratio in both directions. A 20 km range colorless WDM-PON without dispersion compensation was demonstrated...
In transparent optical networks, physical layer impairments (PLIs) incurred by non-ideal optical transmission media accumulate along an optical path, and the overall effect determines the feasibility of the lightpaths. If the received signal quality is not within the receiver sensitivity threshold, the receiver may not be able to correctly detect the optical signal. Hence it is important to understand...
Simultaneous transmission was achieved of 40 Gbps at baseband and 2.5 Gbps modulation on a 50 GHz subcarrier utilizing a single 40 Gbps light-intensity modulator. A novel reception method based on optically separated baseband and single sideband channel permits direct detection of both signals with use of bandwidth limited photodiodes and dispersion tolerant transmission. This method can be used to...
An automatic frequency control design is proposed and demonstrated. It is based on a high-speed optical VCO. An overall design has been performed, based on simulation results. Also, loop delay and phase noise impacts have been evaluated. Frequency discriminator and VCO proposed have been experimentally characterized, showing an agreement with simulation results.
The growth of bandwidth demand due to increasing number of users and available services, led to development of optical networks. In order to reduce its complexity and cost, Fabry-Perot Bragg Grating (FPBG) based devices are strong candidates to be used in these networks. In the presented work, the same device is able to provide functionalities like optical carrier recovery in a wavelength division...
In this paper we present the impact of considering regenerator allocation when selecting routes and wavelengths in translucent networks. In the regular operation of translucent networks, i.e. with dynamic traffic, we assume that a certain number of 3R regenerators are installed in some nodes of the network. These regenerators break the optical transparency of the lightpaths, but allow establishing...
The paper addresses OFDM transmission over optical links with low and moderate cost optics which is mandatory in access and in metro applications. Here we address especially direct detection receivers using photo detectors without the need for local lasers at the transmitter side. Thus the transmission becomes nonlinear due to the magnitude squared envelope detection which requires attention when...
Reliability of optical networks depends on reliability of components. This in turn strongly depends on the detailed design of the structures, processes and technologies used to fabricate them. Reliability testing and investigation must start at the beginning of the design phase to expose any potential weaknesses of the design. This paper reviews the reliability testing that was undertaken on an optical...
We report on the recent progresses in the wavelength-division-multiplexed passive optical network (WDM PON) based on the reflective semiconductor amplifiers (RSOAs), including the enhanced operable temperature range, effects of reflection and its mitigation methods, 10 Gb/s operation by using electronic equalizers and forward error-correction (FEC) codes, and increased maximum reach to >100 km...
Growing needs to transport large amount of data, penetration of multimedia into our daily lives, and quickly expanding e-commerce sector triggered an unparallel demand for the new generation of fast, secure, and energy savvy communication networks. Today we already benefit from many advances which revolutionized data and voice communication. Commercially deployed dense wavelength division multiple...
We discuss and compare several concepts of optical cryptographic systems currently being proposed to improve communication security, their strong points and weaknesses. We will focus on approaches based on chaos synchronization.
Optical and wireless integration in the same platform is an essential requirement for future access networks in order to achieve an economically feasible business model, especially for the deployment of Next Generation Networks. The combination of both technologies offers high bandwidth together with mobility, thus making a strong contribution to future high capacity applications. PON (passive optical...
We propose an Ultra-Dense Wavelength Division Multiplex Passive Optical Network (UD-WDM-PON) based on homodyne detection in a totally transparent ring-tree implementation. It is based on time switching phase diversity homodyne detection and local oscillator reuse for upstream transmission. 4 GHz spaced 1 Gb/s streams were correctly received in a 30 km experimental deployment serving 1024 users.
The usage of optical single-sideband signals (OSSB) in 40 Gb/s transmission systems using electrical dispersion compensation (EDC) as a cost-effective alternative to optical dispersion compensation (ODC) is investigated. Optimization of the pseudo-linear regime by adjusting the amount of dispersion compensated at the transmitter and receiver sides is performed using OSSB signals associated with alternative...
We derive a differential Q factor model for DPSK signals detected by delay line demodulators. The parameters involved in the model are related to signal characteristics such as phase noise linewidth, OSNR and power fluctuations, and can therefore be directly monitored from it. Moreover, its validity is tested and confirmed under various phase noise and amplitude fluctuations scenarios. In addition,...
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