Analysis of optical filtering in waveguides with a high index modulation using the extended coupled mode theory by hybridization of a matrix method

International audienceIn this paper the authors present an hybrid approach for the analysis of the optical filtering function in corrugated waveguide filters with a high index modulation. This approach is based on the hybridization of the extended couple mode theory (CMT) with the transfer matrix approach. The authors chose to treat the case of high index corrugation because in this case the theory elaborated before is not rigorously applicable. The proposed approach allows the calculation of the reflection coefficient and the full width at half maximum (FWHM) for any index modulation scheme. The hybridization of both methods mentioned above explains the impact and effects of opto-geometric parameters on the reflection coefficient and the bandwidth at mid-height. The theoretical results are verified by experimental measurements realized on Ti:LiNbO3 waveguides with a high index modulation experimentally implemented by engraving using Focused Ion Beam (FIB) process

Veiled Politics: Muslim Women's Visibility and Their Use in European Countries' Political Life

One of the many disastrous consequences of the tragic events of 9/11 is the war waged by the neocolonialists in order to "liberate" Muslim women. This gender-based war stands on a series of pillars, such as the presumption that Western civilization offers women a great deal of privileges, while Muslim culture gives none. Therefore, it would be logical to suppose that, because of the many opportunities the West grants to Muslim women who reside there, the latter may have an active role in the local political process. However, Muslim women have scarce visibility in European political life, and their presence is sometimes merely instrumental to some party: in most cases, women are coopted because they are a good sample of "secular Muslims" ( i.e. , they do not wear the hijab , i.e. , the veil and a modest attire); in others, they are appointed because they are veiled and can therefore become a good vehicle in order to win the support both of the Muslim community and of its sympathizers. In this paper, I will analyze some crucial aspects of Muslim women's formal political participation in some European countries; in addition, I will focus on the Italian case with the help of a series of interviews with Muslim women who play an active role in local political councils. The study shows how in European politics, Muslim women can become a commodity even when they stand out as rising political individuals; but also how they fight to gain visibility and public recognition, in spite of the tense situation and of the rampant Islamophobia

Gain-loss tradeoff in the performance of high index modulation Bragg filters

In this article we explain the gain-loss trade-off by studying the effect of the etching depth l on the reflectivity R and the losses related to optical filters based on Bragg grating (BG). This study has demonstrated that from an optimal modulation depth the desired transfer function of the filter can be the most appropriate in terms of performance. We were also able to experimentally calculate this optimal engraving depth on several realizations. This made it possible to show that once the reflectivity reaches its maximum value, it is useless to exceed this depth value because it does not improve the reflection gain but it only increases the losses related to the BG. This increase in losses leads to the degradation of the quality of the transmission by increasing the probability of error and decreasing the bit rate

Improving ROCs of Constant False Alarm Coded Anti-collision Radar in very noised cases

The use of Constant False Alarm Coded Anticollision Radar (CFACAR) is very interesting in automotive environment. Due to the orthogonality properties of used codes this system is most robust to multi-user interferences. The actual version of the receiver called in this paper Single Correlation Receiver (SCR), is not able to detect the targets in very low input Signal to Noise Ratio (SNR). To resolve this problem, we present a new receiver called Averaging Correlation Receiver (ACR), that computes the average of the M later correlations.Then, we developed the expression of detection and false alarm probabilities for the new receiver in mono and multi-user scenarios. These probabilities are used to plot the new Receiver Operating Characteristics (ROCs). They are drawn for different values of input SNR and length M of ACR. There is a suitable value of M, according to some equation, that can be taken to have a good detection (ROCs more perfect). Also, we found that for a fixed SNR, we must increase sufficiently the length M but it is possible only for low relative velocity of the target. For a velocity of 5Km=h with M = 1055, we can lessen the value of the SNR until we reach SNR = -45 dB

Exaltation de l'émission spontanée à 1,53 µm dans un guide réalisé par diffusion de titane dans un substrat de niobate de lithium dopé à l'erbium et pompé optiquement à 980 nm

National audienceNous proposons la réalisation d'un laser guide d'onde, à base de niobate de lithium dopé à l'erbium (Er:Ti:LiNbO3) pour une émission à 1,53 µm. Sa cavité est constituée de deux nanostructures à bande interdite photonique couplées afin de renforcer l'émission spontanée à cette longueur d'onde. Une cellule a été conçue, réalisée et caractérisée. Un gain optique de 8 dB a été obtenu, confirmant ainsi l'effet d'exaltation attend

Analysis of a novel photonic-crystal LOM structure engraved in a Ti:Er:LiNbO3 waveguide for 1.55 µm emission

International audienceA novel laterally overmodulated (LOM) structure of lithium niobate photonic crystals (PCs) is presented and theoretically analyzed with band diagrams calculated by the plane-wave expansion technique for periodic structures and transmission spectra evaluated by the 2D finite-difference time domain (FDTD) method. The LOM structure is based on a triangular lattice of air holes drilled in the top surface of a titanium-diffused erbium-doped lithium niobate waveguide Ti:Er:LiNbO3. The LOM operates in a distributed-feedback (DFB)-like regime and its parameters are designed to maximize the spontaneous emission rate at 1.55 µm. The first experiment shows an optical amplification close to 9 dB at 1.55 µm

Une étude complète sur le modèle de découpage du réseau E2Ee bout-en-bout 5G

International audienceAujourd'hui, la technologie de découpage en tranches de réseau est massivement étudiée par la communauté des chercheurs. Cependant, les détails de la modélisation des tranches de réseau (NS) des organismes de normalisation (SDO) ne sont pas encore bien pris en compte pour les implémentations de NS de bout en bout (E2E). En outre, chaque SDO élabore des normes et des modèles d’information qui ne visent qu'une partie spécifique de l'architecture NS. Notre travail présent un survey, le premier dans la littérature, qui analyse l’ensemble des modèles d’information et de données actuellement proposés par ces différents organismes de standardisation. Ce travail permet une définition approfondie de ce qui un Network Slice est (et du comment le définir), indépendante de la technologie. Cette compréhension est nécessaire pour construire des solutions complètes de Network Slicing de bout-en-bout.Sur la base d'une analyse approfondie des principaux travaux existants dans la littérature, cet article explique tout d'abord (i) une architecture générale qui clarifie la fonctionnalité de base du découpage de réseau E2E avant de plonger dans des visions spécifiques au domaine. Ensuite, (ii) il se concentre sur la fourniture d'une étude regroupant les travaux de modélisation des NS dans les réseaux d'accès radio (RAN), les réseaux centraux (CN) et les réseaux de transport (TN). L'objectif final est de clarifier le processus de découpage du réseau E2E, depuis la demande de service jusqu'au déploiement des réseaux de transport et à la gestion de leur cycle de vie. Enfin, comme il n'y a pas de consensus sur un modèle d'information spécifique dans les domaines des réseaux de transport (iii), nous présentons notre vision de la manière dont plusieurs modèles de données, développés par des groupes de travail de l'IETF, peuvent être intégrés dans le contexte de l'architecture ACTN afin d'approvisionner et de gérer les réseaux de transport

NESSMA: Network Slice Subnet Management Framework

Network Slicing is becoming a mature technology in recent years due to the continuous efforts conducted by the standards organizations, academic units and operators. However, current Network Slice (NS) demonstrations are not fully aligned with the ongoing standardization activities, particularly with the Network Slice Subnet Management Function (NSSMF) defined by 3GPP. This paper provides a novel Framework for NS Subnet Management, called NESSMA, that satisfies a list of requirements derived from an exhaustive analysis of up-to-date NS standards. The Framework is designed to jointly manage NS Subnets and their supported services having in mind its integration with NFV-MAN

Veiled Politics: Muslim Women’s Visibility and Their Use in European Countries’ Political Life

One of the many disastrous consequences of the tragic events of 9/11 is the war waged by the neocolonialists in order to "liberate" Muslim women. This gender-based war stands on a series of pillars, such as the presumption that Western civilization offers women a great deal of privileges, while Muslim culture gives none. Therefore, it would be logical to suppose that, because of the many opportunities the West grants to Muslim women who reside there, the latter may have an active role in the local political process. However, Muslim women have scarce visibility in European political life, and their presence is sometimes merely instrumental to some party: in most cases, women are coopted because they are a good sample of "secular Muslims" ( i.e. , they do not wear the hijab , i.e. , the veil and a modest attire); in others, they are appointed because they are veiled and can therefore become a good vehicle in order to win the support both of the Muslim community and of its sympathizers. In this paper, I will analyze some crucial aspects of Muslim women's formal political participation in some European countries; in addition, I will focus on the Italian case with the help of a series of interviews with Muslim women who play an active role in local political councils. The study shows how in European politics, Muslim women can become a commodity even when they stand out as rising political individuals; but also how they fight to gain visibility and public recognition, in spite of the tense situation and of the rampant Islamophobia