Navegando por Assunto "Fator de qualidade"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Portas lógicas totalmente ópticas baseado em interferômetro de Michelson com amplificador óptico semicondutor
(Universidade Federal do Pará, 2018-08-24) OLIVEIRA, Jackson Moreira; COSTA, Marcos Benedito Caldas; http://lattes.cnpq.br/7636226766852440
In this work, proposes all-optical logic gates device structure based on a Michelson interferometer (MI) composed of semiconductor optical amplifier (SOA) forming a structure of SOA-MI logic devices with symmetrically identical Fiber Bragg Grating (FBG) at the output of each of its arms, for numerical simulation of the all-optical AND, OR and NOR logic gates of two binary input signals with different bit numbers using the cross-gain modulation (XGM) technique at 10 Gb/s bit rate and filter bandwidth at 10, 20 and 40 GHz using OptiSystem 15.0 software by OptiWave Corporation, to demonstrate and extract simple design rules for high-speed optical processing and analysis of non-linear SOA-induced properties. In addition, this work includes the study of the effect of bandwidth and number of bits on received power, minimum bit error rate (BER), maximum quality factor (Q-factor), Optical Signal to Noise Ratio (OSNR) and optical spectrum, which demonstrates high-speed gates and performance. Were run the SOA-MI-based logic gates with some parameters and the results can demonstrate a structure of high-performance optical logic devices with high speed.
Acesso aberto (Open Access)
Regenerador 3r totalmente óptico baseado em interferômetro de Mach-Zehnder de fibra de cristal fotônico altamente não linear
(Universidade Federal do Pará, 2017-05-26) SOUSA, Fabio Barros de; COSTA, Marcos Benedito Caldas; http://lattes.cnpq.br/7636226766852440
The present work aimed to investigate by means of numerical simulations, a device able to perform 3R regeneration (Re-amplifying, Re-timing and Re-shaping) fully propagated signal in an optical communication system for optical fiber with bit rate of 10 Gbit/s, the initial transmit power 0 dBm and wavelength of 1550 nm. As an ally to the regeneration process using dispersive and nonlinear effects of self-phase modulation (SPM), cross-phase modulation (XPM) and four-wave mixing (FWM) in a Mach-Zehnder Interferometer, whose one of the arms is composed of a Highly Nonlinear Photonic Crystal Fiber (HNL-PCF). The simulations were performed using OptiSystem commercial software of company canadian Optiwave Corporation. System performance was analyzed by comparing the values of the quality factor (Q-factor), of the bit error rate (BER), of optical spectrum and the optical signal-to-noise ratio (OSNR) optical signals are regenerated, before regenerated and degraded in the entrance and exit of the proposed system. Through this project, it was possible to obtain an efficient signal regeneration, with optimal values of OSNR, quality factor (Q-factor) and low bit error rate (BER).
Acesso aberto (Open Access)
Seismic amplitude analysis and quality factor estimation based on redatuming
(Universidade Federal do Pará, 2015-04-25) OLIVEIRA, Francisco de Souza; FIGUEIREDO, José Jadsom Sampaio de; http://lattes.cnpq.br/1610827269025210
Amplitude correction is an important task to correct the seismic energy dissipated due the ineslasticity absortion and the geometrical spreading during the acoustic/elastic wave propagation in solids. In this work, we propose a way to improve the estimation of quality factor from seismic reflection data, with a methodology to estimate de quality factor based on the combination of the peak frequency-shift (PFS) method and the redatuming operator. The innovation in this work is in the way we correct travel times when the medium is consisted by many layers. In other words, the correction of traveltime table used in the PFS method is performed using the redatuming operator. This operation, which is performed iteratively, allows to estimate the Q-factor layer by layer in a more accurate way. A redatuming operation is used to simulate the acquisition of data in new levels, avoiding distortions produced by near-surface irregularities related to either geometric or material property heterogeneities. In this work, the application of the true-amplitude Kirchhoff redatuming (TAKR) operator on homogeneous media is compared with conventional Kirchhoff redatuming (KR) operator restricted to the zero-offset case. Our methodology is based on the combination of the peak frequency-shift (PFS) method and the redatuming operator (TAKR with weight equal 1). Application in synthetic and in seismic (Viking Graben) and GPR (Siple Dome) real data demonstrates the feasibility of our analysis.