Papers by Fabio Barros de Sousa
Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Apr 14, 2017
Proceeding Series of the Brazilian Society of Computational and Applied Mathematics, Apr 14, 2017
Materials Research-ibero-american Journal of Materials, 2021
Research Square (Research Square), Nov 11, 2022
Brazilian Journal of Development
Neste trabalho, investigamos um método de compensação de dispersão para as taxas de transmissão d... more Neste trabalho, investigamos um método de compensação de dispersão para as taxas de transmissão de 10 Gbps e 40 Gbps com formatos de modulação retorno ao zero (return to zero - RZ) e não retorno ao zero (non-return to zero - NRZ) usando fibra monomodo (single mode-fiber - SMF) e fibra compensadora de dispersão (dispersion compensating fiber - DCF). A influência da dispersão do compensador DCF com o aumento da potência do laser CW foi estudada, afim de se avaliar o desempenho dos sistemas de comunicação por fibra óptica aqui propostos. Os resultados da simulação foram validados através do formato do pulso, do espectro óptico e do diagrama de olho para a análise do fator Q e da taxa de erro de bit (bit error rate – BER).
Brazilian Journal of Development
In this paper, we investigate two dispersion compensation methods: post-compensation, and pre-com... more In this paper, we investigate two dispersion compensation methods: post-compensation, and pre-compensation for transmission rates from 10Gbps to 40Gbps with return to zero (RZ), non-return to zero (NRZ) and Guassian modulations using single fiber mode-fiber (SMF) and dispersion compensating fiber (DCF). The influence of the DCF compensator dispersion with different transmission rates was studied in order to evaluate the performance of the proposed systems. The simulation results were validated through the analysis of the quality factor (Q-factor) and the bit error rate (BER), where it was verified that the post-compensation system with Gaussian modulation offered better performance results in function of the transmission rate variation.
Conjecturas, 2022
This work aims to discuss a study of numerical simulations of the performance of arrayed waveguid... more This work aims to discuss a study of numerical simulations of the performance of arrayed waveguide grating (AWG) and fiber Bragg grating (FBG) demultiplexers in a fiber optical network in a special class of fiber denominated fiber of photonic crystal (PCF) considering the dispersive and non-linear effects. The proposed method is based on numerical simulations in a wavelength division multiplexing (WDM) network configuration in PCF. For the simulation and analysis, the commercial OptiGrating software was used, a versatile numerical tool used to model integrated devices that incorporate FBG and OptiSystem software to simulate fiber propagation with non-linear and dispersive characteristics. The analysis of the performance of the systems was done through a comparison between the values obtained in terms of Bit Error Rate (BER) and Quality Factor (Q Factor) in a dense WDM system with spacing between 50 GHz channels, and 12 Gbit/s transmission rate. The results show that the FBG demultip...
Journal of Computational and Theoretical Nanoscience, 2020
In this work, we propose a fiber optic point dendrometer with two Fiber Bragg Grating (FBG) senso... more In this work, we propose a fiber optic point dendrometer with two Fiber Bragg Grating (FBG) sensors capable of simultaneously measuring strain and temperature considered suitable for monitoring the growth of the diameter of trees in the Amazon compared to conventional electrical sensors and we perform a simulation on the performance of the sensors for measuring the diameter using the Coupled Mode Theory (CMT) and the Transfer Matrix Method (TMM). A measure of the diameter variation was suggested and the sensitivity of the sensors were analyzed from the measurements of the displacements of the Bragg wavelengths varying simultaneously the strain and the temperature. The results showed that the proposed configuration, thermally varied from 0 °C to 80 °C and deformed from 0 to 2400 μ could specifically detect minute variations in diameters with a resolution of 0.5 μm (0.0005 mm) with good linearity staying with a variation of the Bragg wavelength 0.12 nm for each 10 °C and 0.24 nm for e...
Journal of Computational and Theoretical Nanoscience, 2020
In this work we study the non-linear effects through the analysis of the operating results of thr... more In this work we study the non-linear effects through the analysis of the operating results of three alloptical 3R regeneration (re-amplifying, re-shaping and re-timing) under the effects of cross-phase modulation (XPM) and four-wave mixing (FWM), being a system with hybrid modulation and two other communication systems with modulation on-off keying (OOK) with return to zero (RZ) and non-return to zero (NRZ) coding. The main part of the 3R regeneration system proposed here is a Mach-Zehnder interferometer (MZI) composed of an acousto optical filter (AOF) and a highly nonlinear photonic crystal fiber (HNL-PCF), so the system proposed here was named 3R-MZIAOF regenerator. The comparison of the system results occurred through the variation of the input power variation from -10 dBm to 10 dBm for the link length of 121.3 km and transmission rate 10 Gbps. The results showed that the regeneration 3R scheme OOK-NRZ with AOF presented excellent values of bit error rate (BER) equal to 10-21 an...
Scientia Plena, 2019
The manuscript presents Design of All-optical AND logic gate at 20 Gb/s using Semiconductor Optic... more The manuscript presents Design of All-optical AND logic gate at 20 Gb/s using Semiconductor Optical Amplifier based on Michelson Interferometer (SOA-MI). The paper shows a comprehensive numerical simulation using OptiSystem software to examine two-input logical function (with 8-bit). Used the CW Laser, Dual Directional Coupler, 100% reflective linear Fiber Bragg Grating (FBG) and Optical Filter, and investigated the optimum injection current and length of the TWA-SOA for obtaining the best result Q-Factor and BER based on Eye diagram to logic gate. To the best of our knowledge, this is the first report on a numerical simulation of an All-Optical AND logic gate at 20 Gb/s with SOA-MI using co-propagating, structure with results ensure good performance of the proposed design.
Scientia Plena, 2019
In this paper a simplified design and efficient of a Michelson Interferometer (MI) system is pres... more In this paper a simplified design and efficient of a Michelson Interferometer (MI) system is presented, capable of reducing the Four-Wave Mixing (FWM) effects, using fiber Bragg grating and acoustic optic filter (FBG and AOF) with the aid of a highly non-linear photonic crystal fiber (HNL-PCF). The analysis of the MI system based in FBG and AOF was performed according to the effect of fiber length and input power by performance metrics: Optical Spectrum, maximum Quality factor (max. Q-factor), minimum bit error rate (min. BER), eye height, optical signal-to-noise ratio (OSNR) and timing jitter. The numerical simulation results showed that the MI system with FBG and AOF maintained a good signal performance, with Q-factor equal to 33.3 even after 100 km of single mode fiber (SMF) and with downstream signal power by up to 10 dBm.
Journal of Computational and Theoretical Nanoscience, 2019
Journal of Computational and Theoretical Nanoscience, 2019
In this paper we investigate the performance of a Fiber Bragg Grating (FBG) as a strain-optic and... more In this paper we investigate the performance of a Fiber Bragg Grating (FBG) as a strain-optic and temperature sensor, using the Coupled Mode Theory (CMT) and the Transfer Matrix Method (TMM), through numerical simulation in an interrogation system with Single-Mode Fiber (SMF) and Photonic Crystal Fiber (PCF). Parameters such as sensitivity, bandwidth, peak power, peak wavelength and side-lobes power, were analyzed through the Bragg wavelength change depending on the simultaneous variation of strain and temperature. The FBG sensor proposed suffered thermal variation 25 °C to 200 °C and of strain of 0 μs to 1000 μs, excellent linearity was obtained for the variation of the Bragg wavelength with differences of 0.7 nm for each 50 °C and 0.245 nm for each 200.
Brazilian Journal of Development
In the present work, an optical directional coupler (ODC) based on two-dimensional (2-D) photonic... more In the present work, an optical directional coupler (ODC) based on two-dimensional (2-D) photonic crystal (PhC) was analyzed and proposed, through the methods of plane wave expansion (PWE) and finite-difference time-domain (FDTD), which were used with the purpose of analyzing the behavior of a new all-optical NOT logic gate and the electric field distribution in the coupler for linear (bar), non-linear (cross) states and the control signal. The simulation results in OptiFDTD software show that the proposed crystal structure is a strong candidate for use in ultrafast photonic integrated circuits (PICs), being highly advantageous with excellent transmission performance and simple design.
Optics Express, 2007
In this paper, the implementation of an all-optical logic gate based on a Mach-Zehnder interferom... more In this paper, the implementation of an all-optical logic gate based on a Mach-Zehnder interferometer (MZI) configuration is addressed with underlying nonlinear slot-waveguides. In order to reduce power consumption requirements, different ring-resonator structures are introduced in the arms of the MZI. A nonlinear Transfer Matrix Method is developed and used to analyze the response of the nonlinear MZI in order to optimize power requirements with maximum bit rates. The numerical analysis shows that a reduction in the switching power from 2.5 W to less than 5 mW can be achieved by a proper design of the ring-resonator structures introduced in the MZI arms. In addition, it is shown that the logic gate can handle bit rates higher than 60 Gbit/s.
Optical and Quantum Electronics
In the present work is used the nonlinear resonance caused by excitation of Erbium ions located o... more In the present work is used the nonlinear resonance caused by excitation of Erbium ions located on central row of a Photonic Crystal directional coupler. Such excitement causes the transition of Erbium ions from the ground state to the metastable doing the amplification of the signal when the photons absorb the light emitted by the signal. The simulations occurred in software COMSOL Multiphysics, which uses the Finite Element Method (FEM). A comparative analysis was performance between a directional coupler of Photonic Crystal doped with erbium and another not doped. It was verified the switching performance of both from the variation of normalized frequency and it was verified that the doped coupler was able to operate in the bar and cross states with higher frequency spectrum. Keywords— coupler; Photonic Crystal; erbium; switching.
Optical and Quantum Electronics, 2021
In this work, we presented a radio-over-fiber (ROF) access network through two modulation stages ... more In this work, we presented a radio-over-fiber (ROF) access network through two modulation stages for the generation of multiple millimeter wave (mm-wave) signals with frequencies of 20GHz, 40GHz, 60GHz and 80 GHz for the transmission rate of 10 Gbps as a function of the variation of link distance and signal power. The specific purpose of the paper was to design and to investigate a RoF system based on the variation of mm-wave frequencies in order to implement a simple and effective system. In stage 1, there are two modulators in parallel (MZMa and MZMb) called dual-parallel Mach-Zehnder modulator (DP-MZM) and in stage 2 there is only one modulator (MZMc), connected to three pulse generators: Non-Return-to-Zero (NRZ), Return-to-Zero (RZ). A single-mode fiber (SMF) and Gaussian and an erbium-doped fiber amplifier (EDFA) were also used to send signals to base stations (BSs). The numerical analyzes of the results of the eye diagrams showed excellent bit error rate (BER) and quality factor (Q-factor) values, which proved the good performance of the proposed ROF DP-MZM system, for the three encoding formats used, which was able to generate 3-tupling mm-wave for multiple wireless accesses.
International Journal of Innovative Research in Computer and Communication Engineering, 2017
This paper aims to present a fiber optic telecommunications network design capable of suppressing... more This paper aims to present a fiber optic telecommunications network design capable of suppressing noise and improving the quality of the transmitted signal through the self-phase modulation effect in a highly nonlinear fiber (HNLF), thus allowing the regeneration 2R (Reamplification and Reshaping) in a totally optical way. For a distance of up to 300 km of SMF, the values of factor Q = 6, BER = 10-9 and OSNR = 13.5 dB were found. The project was developed and simulated in Optisystem software. The results confirm that the proposed 2R regenerator was efficient.
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Papers by Fabio Barros de Sousa