A Radio over Fiber (RoF) Based Single Sideband Modulated Passive Optical Network (PON) Using Mach Zender Modulator Based on Different Electrical Phase Shifts

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Hilal Ahmad Sheikh ◽  
Anurag Sharma
Keyword(s):  
Phase Shift ◽  
Optical Network ◽  
Phase Shifts ◽  
Radio Over Fiber ◽  
Second Order ◽  
Passive Optical Network ◽  
First Order ◽  
Single Sideband ◽  
Hybrid Coupler ◽  
Shift Technique

AbstractThis research work provides an insight on a radio over fiber (RoF) based passive optical network (RoF-PON) utilizing two diverse electrical phase shifts with optical single sideband modulation (OSSB) by exploiting Mach Zender modulator. The influence of chromatic dispersion (CD) in PONs employing single mode fiber (SMF) is a noteworthy issue and should be limited. The two techniques of OSSB modulation, in view of the two distinct angles of the hybrid coupler are employed for the design and implementation of RoF-PON. The RF signal is partitioned into two ways equally before applying it to the dual drive Mach Zender modulator input, utilizing an electrical hybrid coupler that imparts two discrete phase shifts of 90° and 120° to generate two OSSB signals individually. By utilizing traditional OSSB technique having 90° phase shift, either of the first-order sideband (lower or upper first order) suppression occurs yet second-order harmonics are still existent in the system. As opposed to this, the OSSB technique using 120° phase shift causes the suppression of either lower first order and higher second order sideband or vice versa. When contrasted to the PON based on traditional technique (90° phase shift technique), the suppression of second order sideband in PON using 120° technique lessens the system CD. Hence the PON based on 120° phase shift technique has enhanced functionality in terms of system BER, received power and power losses as compared to that with traditional OSSB technique.

Radio Over Fiber-Based Wavelength Division Multiplexed/Time Division Multiplexed Passive Optical Network Architecture Employing Mutual Injection Locked Fabry-Perot Laser Diodes

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Binoy Das ◽  
Paulomi Mandal ◽  
Khaleda Mallick ◽  
Rahul Mukherjee ◽  
Gour Chandra Mandal ◽  
...  
Keyword(s):  
Optical Network ◽  
Laser Diodes ◽  
Radio Over Fiber ◽  
Injection Locking ◽  
Passive Optical Network ◽  
Wavelength Division ◽  
Wavelength Division Multiplexed ◽  
Fabry Perot ◽  
Time Division ◽  
Mutual Injection Locking

AbstractWe demonstrate a radio-over-fiber-based hybrid wavelength-division-multiplexed/time division multiplexed passive optical network (PON) to transmit 5 Gbps data rate to serve 32 subscribers. A broadband light source (BLS) is realized by mutual injection locking between two Fabry-Perot laser diodes at the transmission section to seed wavelength-division-multiplexed channels. Mutual injection locking technique is used to enhance the performance over single Fabry-Perot laser diode and 15  dB/Hz improvements in relative intensity noise(RIN) is realized in our proposed network system. All-optical up-conversion of a 10-GHz 1.25 Gbps on off keying radio frequency (RF) signal is achieved using one single-arm Mach-Zehnder modulator (MZM). Transmission performance over 25-km single mode fiber is investigated. Low bit error rate with enhanced eye-diagram is obtained in our proposed system. As a result, the radio over fiber (ROF)-based wavelength-division-multiplexed/time division multiplexed PON set up employing mutually injection locked Fabry-Perot laser diodes can be a better choice in high speed long-haul optical communication system.

A NEW LOOK AT THE DUAL DEPTH OF INVESTIGATION OF LWD PROPAGATION RESISTIVITY LOGGING

2021 ◽  
Author(s):  
Gong Li Wang ◽  
◽  
Dean Homan ◽  
David Maggs ◽  
David Allen ◽  
...  
Keyword(s):  
Phase Shift ◽  
Eddy Current ◽  
Second Order ◽  
Vertical Resolution ◽  
Shift Measurement ◽  
Attenuation Measurement ◽  
First Order ◽  
Dielectric Effect ◽  
The Difference ◽  
Resistivity Logging

It is well established that phase shift and attenuation measurements acquired by an electromagnetic propagation tool come with different depths of investigation (DOI). The attenuation measurement sees deeper into the formation than the phase shift measurement. This difference has been reported not only for the 2 MHz propagation resistivity tool, but also for the deep propagation tool that operates at 25 MHz. Although the difference has been demonstrated with modeling, test tank experiments and logs, a complete physical explanation has been notably absent since the introduction of the MHz-frequency propagation logging in 1980s. The question is so intriguing that it has been raised repeatedly over the past decades: what drives the difference of DOI for the two measurements that are acquired with the same electromagnetic field? In this paper, we revisit this problem with an aim of providing a physical insight to bridge the gap between theory and application. This is an extension of our recent work on the theory of apparent conductivity for propagation measurements. We address the problem by applying high-order geometric theory for low-frequency electromagnetic problems in lossy media in conjunction with the Taylor series expansion for the voltage ratio measured by a propagation tool. In so doing, we find that in a resistive formation where the dielectric effect is small: 1) the phase shift measurement is primarily due to the first-order eddy current induced in the formation; 2) in contrast, the leading source of the attenuation measurement is the second-order eddy current. Since the second-order eddy current is more spread out than the first-order eddy current, this explains why the DOI of attenuation resistivity is larger than that of phase shift resistivity. The difference in spatial distribution of two eddy currents is also the reason for the difference of vertical resolution between the two. The same root cause for the difference of DOI and vertical resolution also holds when comparing R-signal and X-signal from induction resistivity logging. Other properties shared by propagation and induction resistivity logging will be discussed, such as skin effect and dielectric effect, as well as their asymptotic properties in high-resistivity formations. We conclude that propagation and induction resistivity logging are essentially similar, even though the two measurement principles may seem rather different.

scholarly journals Automodulación de fase en redes ópticas pasivas de próxima generación, utilizando modulación por desplazamiento cuaternario de fase

Respuestas ◽  
2017 ◽  
Vol 22 (1) ◽  
pp. 37
Author(s):  
Yhon Edinson Estevez-Mendoza ◽  
Byron Medina-Delgado ◽  
Luis Leonardo Camargo-Ariza
Keyword(s):  
Phase Shift ◽  
Fiber Optics ◽  
Single Channel ◽  
Transmission Rate ◽  
Fiber Type ◽  
Optical Network ◽  
Effective Area ◽  
Passive Optical Network ◽  
International Telecommunication Union ◽  
Nonlinear Error

Antecedentes: la información en un canal de fibra óptica sufre distorsiones debido a la aparición de efectos lineales y no lineales, restringiendo la velocidad de transmisión. En este documento se analiza el error no lineal denominado automodulación de fase (SPM),el cual genera un desfase en los pulsos trasmitidos, ocasionando errores de bits en la comunicación. Objetivo: el proyecto está orientado a evaluar el comportamiento del error no lineal SPM en una comunicación monocanal de fibra óptica utilizando Matlab. Métodos: su desarrollo parte del modelado matemático del error SPM, para ser codificado en Matlab y evaluar su desempeño en el canal para condiciones específicas. Para realizar las simulaciones se implementó un canal de comunicaciones en fibra óptica, teniendo en cuenta los parámetros que rigen las redes XGPON o 10GPON que son la siguiente generación de Red Óptica Pasiva con Capacidad de Gigabit (GPON). Para simular el canal de fibra óptica se definieron las distancias de 20, 40 y 60 km, y las potencias de 4, 10 y 20 mW, con velocidades de transmisión de 10 Gbps, en las longitudes de onda de 1550 y 1310 nm, usando la modulación QPSK. Los parámetros para desarrollar la simulación consideraron las recomendaciones de la Unión Internacional de Telecomunicaciones (ITU). Resultados: mediante un análisis gráfico se identificaron los parámetros que afectan el error SPM, como la potencia, el área efectiva, la distancia y el tipo de fibra, entre otros. Conclusión: el error SPM por sí solo no es perjudicial para las redes XGPON en la modulación QPSK, considerando que el máximo desfase obtenido en el proyecto fue  de 28.8°, siempre y cuando se tengan en cuenta la potencia, la distancia y los tipos de fibra, de acuerdo con las recomendaciones de la ITU (G652, G987, G691 y G957). Palabras clave: Automodulación de fase, fibra óptica monomodo estándar, modulación por desplazamiento cuaternario de fase, red óptica pasiva con capacidad de gigabit.AbstractBackground: the information transmitted by optical fiber channels is distorted due to the appearance of linear and nonlinear effects, which restrict the transmission rate, this paper  analyzes the nonlinear error selfphase modulation (SPM) Objective: the project aims to evaluate the behavior of nonlinear error SPM in a single channel fiber optic communication using Matlab. Methods: development of the mathematical modeling of error SPM to be coded in Matlab and evaluate their performance in the channel for specific conditions. To perform simulations a communications channel is implemented in fiber optics taking into account the parameters governing XGPON or 10GPON networks or which are the next generation of Gigabit Passive Optical Network (GPON). To perform simulations three distances 20, 40 and 60 km, and three power values of 4, 10 and 20 mW were defined, with transmission speeds of 10 Gbps wavelengths 1550 and 1310 nm, respectively; using QPSK modulation. The parameters to simulate were defined taking into account the recommendations of the International Telecommunication Union (ITU). Results: using a  graphical analysis we identified the parameters that affect the error SPM, such as potency, the effective area, the distance, the fiber type, among others. Conclusion: the error SPM alone is not harmful to the GPON networks in QPSK modulation, considering that the maximum phase shift obtained in the project was 28.8°, provided that the power, the distance and the types of fiber are taken into account according to the recommendations of the ITU (G652, G987, G691 y G957).Keywords: Gigabit passive optical network, quaternary phase shift keying, self phase modulation, standar singlemode fiber.

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