Frederic LUCARZ - Academia.edu (original) (raw)

Papers by Frederic LUCARZ

HAL (Le Centre pour la Communication Scientifique Directe), Aug 31, 2014

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

HAL (Le Centre pour la Communication Scientifique Directe), Jul 6, 2014

This paper describes for the first time, the design and numerical simulations of an optical modul... more This paper describes for the first time, the design and numerical simulations of an optical modulator from a semiconductor optical amplifier (SOA) inserted into a fibre-optic Sagnac loop electrically modulated by a microwave carrier at 20 GHz frequency and higher. Even though the adopted SOA model presents > 1.4 ns gain recovery time, the device is optically modulated up to 30 GHz because a completely gain recovery is not needed. The interferometric device was shown to present better performance than the solely SOA. It is potentially useful to simultaneously carry out optical modulation, sampling and mixing or to be used simultaneously as a modulator (uplink) and amplifier (downlink) in analogue links.

SBrT 2013

Resumo-Este artigo apresenta a concepção de um transceptor capaz de realizar a digitalização fotô... more Resumo-Este artigo apresenta a concepção de um transceptor capaz de realizar a digitalização fotônica de sinais do tipo Rádio-sobre-Fibra, e no processo inverso recuperar o sinal analógico. A principal contribuição é a descrição do módulo receptor. Trata-se de um sistema formado por diversos circuitos ópticos interconectados, quase todos baseados na configuração interferométrica de Sagnac usando um amplificador óptico semicondutor como elemento não linear. São apresentados resultados de simulação numérica de alguns destes circuitos em até 2,5 GHz. Os circuitos são compactos, o que viabiliza sua implementação em óptica integrada e requerem potência óptica (pico) de controle da ordem de µW-mW.

Journal of Modern Optics, 2015

A novel electro-optical up-conversion mixer architecture comprising four electro-optical phase mo... more A novel electro-optical up-conversion mixer architecture comprising four electro-optical phase modulators situated in the arms between an interconnected 1 × 4 distribution tree and a complementary 4 × 2 combination tree is proposed. The distribution and combination trees are based on multi-mode interference couplers (MMI). The novelty lies in the use of the intrinsic phase relations between the MMI ports to realize a broadband and free of drift design requiring no static phase shift elements. A transfer-matrix approach is followed to represent the main building blocks in the proposed design, and hence to describe the operation of the entire optical up-conversion mixer. The concept is demonstrated by computer simulations. A single side-band modulation with carrier suppression is obtained at the output of the proposed architecture, which is in agreement with the analytical development. Scenarios considering both ideal and imperfect power balances and phase relations in the MMIs, as well as imperfect phase relations of the electrical drives to the phase modulators are analyzed.

Un lien optique d'un système radio-sur-fibre est é tudié pour la transmission de signaux Wi-Fi se... more Un lien optique d'un système radio-sur-fibre est é tudié pour la transmission de signaux Wi-Fi selon le standard IEEE 802.11g OFDM à 2.4 GHz, le lien optique é tant ré alisé par modulation directe d'une source laser suivie d'une photo-dé tection. Aprè s avoir analysé les principaux paramè tres RF du lien optique en termes de gain, bruit et non-liné arité , ses performances ont é té é valué es, mettant en é vidence une limitation due aux composants optoé lectroniques. Une amé lioration de ces performances peut ê tre obtenue en adaptant la dynamique du lien optique à celle du lien radio. Une solution consiste à ré duire le bruit (RIN) de la source laser utilisé e (VCSEL) et s'affranchir d'un faible IIP3 imposé par l'amplificateur trans-impé dance du photodé tecteur (PIN).

Erbium-doped glasses are of prime importance for optical communication systems as optical gain me... more Erbium-doped glasses are of prime importance for optical communication systems as optical gain media. Indeed, the stimulated photoluminescence of Er 3+ ions in a silica host matrix at the standard 1540 nm telecommunication wavelength corresponds to the minimum attenuation in silica based fibres with a low dispersion. Compact and cost-effective integrated EDWAs (Erbium-Doped Waveguide Amplifiers) on silicon substrates are required for a better implementation of WDM (Wavelength Division Multiplexing) in LANs (Local Area Networks) with a view to extending it to a FFTH configuration (Fibre To The Home) in the future. However, the main drawback of Er-doped silica for designing integrated planar optical amplifier waveguides is the low optical gain per unit length. Rare-earth codopants such as Yb 3+ have already been used but the achievable gain is still too low for further integration on a single silicon chip. These are the main reasons why a novel sensitisation technique for erbium ions is required and has been inquired in this project. As in EDWAs and EDFAs, the aim is to excite Er 3+ ions in their metastable state by means of silicon nanocrystals, in order induce emission of light by stimulated emission at ~1540 nm. The principle of this technique has been thoroughly studied in this project. Optically pumped silicon nanocrystals are used as efficient sensitisers for erbium ions by means of a fast non radiative energy transfer subsequent to the excitation of silicon nanocrystals. The design of small-size (typically less than 8 cm as opposed to the 1 m length in current EDFAs) and broad-band pumpable EDWAs with high gains requires essential parameters to be determined such as the energy transfer rate, the interaction range or critical radius, and the fraction of excitable erbium ions, which are still unknown. To that purpose, we developed a theoretical model based on Förster's theory by analogy with the rare-earth codoped systems. Light emission by silicon nanocrystals in the visible range usually competes with the enhanced photoluminescence of Er 3+ ions. However, the quenching effect of erbium ions upon the ~700 nm photoluminescence from silicon nanocrystals was experimentally evidenced as the concentration of erbium ions increased. This confirmed the strong coupling between the optically generated confined excitons inside silicon nanocrystals and their neighbouring erbium ions within the silica matrix. Two separate sets of experiments on the measurement of the photoluminescence decays from silicon nanocrystals with and without various erbium content were carried out at room temperature in order to evaluate Förster's critical radius (interaction between optically active erbium ions and silicon nanocrystals) The results of the fitting of our experimental data do not seem to be in good agreement with our theoretical model. However, the analysis performed on other authors' experimental curves gave some positive results, leading to the evaluation of the interaction range between Si-ncs and erbium ions. Nevertheless, the derived values for this interaction range are much smaller than expected to allow for optical gain at 1540 nm. Further experimental investigation should be carried out in order to check the validity of this theoretical model.

Techniques for optical generation of millimetre-wave RF carriers are presented. In particular, in... more Techniques for optical generation of millimetre-wave RF carriers are presented. In particular, integrated semiconductor lasers based on lateral coupling of optical modes in a distributed feedback structure are discussed together with preliminary experimental results.

We aim to assess the feasibility of wireless over fibre systems that can operate at millimetre-wa... more We aim to assess the feasibility of wireless over fibre systems that can operate at millimetre-wave frequencies for delivering gigabit/s wireless data to portable or fixed customer units. We have demonstrated the error-free transmission of 1 Gbit/s D-BPSK signals over 2.2 km of single-mode fibre and over 2 metres of RF cable in the 40 GHz band. Wireless-over-fibre is a key technology for providing a future-proof solution to deliver high data rates while extending the coverage of wireless networks. The transparency of analogue optical links to the modulation formats of various wireless signals allows for the simultaneous distribution of multiple services. The high bandwidth and low attenuation of optical fibres can be used to deliver multi- gigabit/s services over long distances. Furthermore, signals conveyed through optical fibres are not prone to radio frequency interference and benefit from enhanced security. As opposed to purely wireless solutions, radio over fibre systems do not...

In this work, the energy efficiency of a Distributed Antenna Systems (DAS) using radio-over-fibre... more In this work, the energy efficiency of a Distributed Antenna Systems (DAS) using radio-over-fibre (RoF) transmission is assessed against a conventional monoantenna system. The power consumption of a Wi-Fi access point and dongle are measured to compute simulations using distance-dependent energy efficiency model. The simulations show that a distributed system with four antennas is almost twice more energy-efficient than a centralized mono-antenna system.

This paper describes an optical Thresholder (o-Thresholder) intended to be part of a transmitter ... more This paper describes an optical Thresholder (o-Thresholder) intended to be part of a transmitter module for future all-optical Digitising Radio-over-Fibre (o-DRoF) transceivers. The proposed device is based on an Attenuation-Imbalanced Semiconductor Laser Amplifier Loop Mirror (AI-SLALOM) in self-switching regime, using the nonlinearities of a semiconductor optical amplifier. Simulations of the proposed AI-SLALOM based o-Thresholder have shown promising results in comparison with the use of standard optical fibre and highly nonlinear fibre only. The newly proposed device is rather compact, optically integrable and requires much less input optical power than conventional devices (by several orders of magnitude). It provides enhanced optical RZ bits at 1550 nm wavelength window, 1.25 GHz repetition rate and 80 ps time-width.

Optics Communications, 2015

ABSTRACT A generalized array of N parallel phase modulators electrically driven with a progressiv... more ABSTRACT A generalized array of N parallel phase modulators electrically driven with a progressive phase shift is analyzed. For N-even, the equivalence of this configuration to parallel Mach–Zehnder architectures, and specifically the equivalence for N=4 to a dual parallel Mach–Zehnder modulator is shown. A simple approach to the design of this architecture that determines the static optical phase shifts required in each of the N parallel arms to suppress unwanted harmonics while maximizing the harmonics of interest is developed. The proposed design approach is validated by numerical simulations of N=4 and N=6 architectures with properly determined optical phase shifts. Optical single-side-band modulation (lower and upper) and frequency multiplication of an electrical drive signal with high suppression of unwanted harmonics is shown to be achievable.

Proceedings of the 2013 18th European Conference on Network and Optical Communications & 2013 8th Conference on Optical Cabling and Infrastructure (NOC-OC&I), 2013

In this paper it is proposed and designed an original all-optical Encoder (o-Encoder) intended, b... more In this paper it is proposed and designed an original all-optical Encoder (o-Encoder) intended, but not exclusively, to be part of future optical digitising radio-over-fibre (o-DRoF) transceiver. It is based on the Semiconductor Laser Amplifier Loop Mirror (SLALOM) configuration exploiting the nonlinearities of a semiconductor optical amplifier (SOA) in cross-switching regime. The proof-of-principle is established using 40-ps RZ control pulses at 2.5 GHz in the C-band. It outputs serially encoded, quantized and amplified optical RZ bits. Computer simulations of the proposed o-Encoder have shown promising results. The proposed device is rather compact, potentially optically integrable and requires much less input optical power (by several orders of magnitude) than other photonic-encoders and can also naturally convert wavelengths in the optical domain.

Proceedings of the 2013 18th European Conference on Network and Optical Communications & 2013 8th Conference on Optical Cabling and Infrastructure (NOC-OC&I), 2013

In this paper it is proposed and designed an alloptical Sampler (o-Sampler) intended to be part o... more In this paper it is proposed and designed an alloptical Sampler (o-Sampler) intended to be part of future optical Digitising Radio-over-Fibre (o-DRoF) transceivers. It is based on the Semiconductor Laser Amplifier Loop Mirror (SLALOM) configuration thus using the nonlinearities of a semiconductor optical amplifier (SOA) in cross-switching regime. The proof-ofprinciple is established by computer simulations using 500 MHz analogue signal and 2.5 GS/s sampling pulses both in the C-band. The proposed o-Sampler outputs real-time generated optical samples from an analogue RoF signal. The simulated device is rather compact, polarisation independent, potentially optically integrable and requires few mW of sampling peak power.

International Journal of Networks and Communications, 2012

Distributed antenna systems (DAS) are known to improve coverage and performance of wireless commu... more Distributed antenna systems (DAS) are known to improve coverage and performance of wireless communicat ions in indoor environ ments. In the present paper, we propose a method to determine the position of distributed antennas that optimizes the network capacity for a given deployment scenario. We also consider power consumption measurements of commercially-available W i-Fi access points and dongles, in order to quantify the energy efficiency of a DAS using Radio-over-Fiber (RoF) technologies. Our results show that there exists an optimal nu mber of distributed antennas for a given topology of the indoor environment.

HAL (Le Centre pour la Communication Scientifique Directe), Aug 31, 2014

HAL (Le Centre pour la Communication Scientifique Directe), Jul 6, 2014

SBrT 2013

Journal of Modern Optics, 2015

Optics Communications, 2015

Proceedings of the 2013 18th European Conference on Network and Optical Communications & 2013 8th Conference on Optical Cabling and Infrastructure (NOC-OC&I), 2013

International Journal of Networks and Communications, 2012