scholarly journals Adaptive Coherent Receiver Settings for Optimum Channel Spacing in Gridless Optical Networks

2019 ◽  
Vol 11 (10) ◽  
pp. 206 ◽  
Author(s):  
Ahmad Abdo ◽  
Sadok Aouini ◽  
Bilal Riaz ◽  
Naim Ben-Hamida ◽  
Claude D’Amours
Keyword(s):  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
High Speed ◽  
Clock Recovery ◽  
Noise Sources ◽  
Wavelength Division ◽  
Optical Channels ◽  
Flexible Rate ◽  
The Media ◽  
Optimum Channel

In this paper, we propose a novel circuit and system to optimize the spacing between optical channels in gridless (also called flexible-grid or elastic) networking. The method will exploit the beginning-of-life link margin by enabling the channel to operate in super-Nyquist dense wavelength division multiplexing mode. We present the work in the context of software-defined networking and high-speed optical flexible-rate transponders. The clock recovery scheme allows the mitigation of jitter by decoupling the contribution of high-jitter noise sources from the clock recovery loop. The method and associated algorithm are experimentally verified where a spectrum gain of up to 2 GHz in spacing between two channels in the Media Channel (MC) is obtained compared to conventional clocking strategies. We showed that the improvement is equivalent to increasing throughput, in a data-center interconnect scenario, by up to 300 giga-bits per second per route.

scholarly journals Modeling and Performance Enhancement of Hybrid Fiber Network-PON/DPPM-DWDM-FSO Communications under Atmospheric Turbulence Conditions

2021 ◽  
Author(s):  
Ebrahim E. Elsayed
Keyword(s):  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
High Speed ◽  
Access Network ◽  
High Signal ◽  
Hybrid Fiber ◽  
Long Distance ◽  
Wavelength Division ◽  
Digital Pulse ◽  
Clear Atmosphere

Abstract A Wavelength Division Multiplexing (WDM) access network using high-speed free-space optical (FSO) communication based on the passive optical networks (PONs) for the distribution link is proposed. In such network architecture, the FSO link can extend the system to areas where an optical fiber link is not feasible, and or provide limited mobility for indoor coverage. The performance of Hybrid Fiber/FSO (HFFSO) network based on digital pulse position modulation (DPPM), for both the indoor and outdoor environments of the optical access network, are compared with the performance of such a network that is based on conventional On-Off Keying Non-Return-to-Zero (OOK-NRZ) modulation using results obtained through computational and analytical modeling. The WDM channels suffer from inter-channel crosstalk, while the HFFSO communication performance in a clear atmosphere is limited by atmospherically induced scintillation. The impairments, plus the amplified spontaneous emission noise from optical amplification, combining in a potentially problematic way, particularly in the upstream direction, which is investigated here. The results obtained indicate that in a clear atmosphere with a sufficiently high signal to crosstalk ratio the proposed system can achieve a human-safe and high-capacity access network. Dense Wavelength Division Multiplexing (DWDM) has dramatically increased the capacity of optical transmission systems. Its inherent advantages have made it the current favorite multiplexing technology for an optical network, also used on fiber optic backbones and long-distance transmission. The crosstalk due to inter-band crosstalk for Ultra-Dense WDM systems causes higher noise and degrades the network performance and analyzed the performance of DWDM-PON link that is corrupted crosstalk for Optical Cross-Connect (OXC). Then the analysis of BER with crosstalk was done. Using the equation for crosstalk number of channels was plotted using Matlab. An analysis is carried out to find the amount of crosstalk considering a WDM-FSO over OOK-NRZ and DPPM based OXC. The bit error rate performance degradation due to crosstalk is evaluated for the OXC parameter and number of wavelength per fiber.

Optical Networks Performance Optimization Based on Hybrid Configurations of Optical Fiber Amplifiers and Optical Receivers

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
I. S. Amiri ◽  
Fatma Mohammed Aref Mahmoud Houssien ◽  
Ahmed Nabih Zaki Rashed ◽  
Abd El-Naser A. Mohammed
Keyword(s):  
Optical Fiber ◽  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
Performance Optimization ◽  
Input Power ◽  
Fiber Amplifiers ◽  
Q Factor ◽  
Wavelength Division ◽  
Transmission Distance ◽  
Optical Fiber Amplifiers

AbstractThe 16-channels dense wavelength division multiplexing (DWDM) systems have been optimized by utilizing hybrid configurations of conventional optical fiber amplifiers (EDFA, RAMAN and SOA) and optical photodetectors (PIN, APD(Si) and APD(InGaAs)). The DWDM systems were implemented for 5 Gb/s channel speed using one of these configurations with 100 GHz channel spacing and 25 km amplifying section. The hybrid configurations are the combinations of (PIN + EDFA), (PIN + RAMAN), (PIN + SOA), (APD(Si) + EDFA), (APD(Si) + RAMAN), (APD(Si) + SOA), (APD(InGaAs) + EDFA), (APD(InGaAs) + RAMAN) and (APD(InGaAs) + SOA). Based on BER, Q-factor and eye diagrams, the performance was compared for these configurations under influences of various thermal noise levels of photodetectors over different fiber lengths ranging from 25 km up to 150 km. The results revealed that both APD structures give optimum performance at input power Pin = 5 dBm due to high internal avalanche gain. EDFA outperforms RAMAN and SOA amplifiers. SOA amplifier shows degraded performance because of nonlinearity effects induced. RAMAN amplifier seems to be the best alternative for long reach DWDM systems because it minimizes the effects of fiber nonlinearities. The configuration (APD(Si) + EDFA) is the most efficient and recommended to be used for transmission distance beyond 100 km due to its larger Q-factor.

scholarly journals EDFA AND EYCDFA POWER BOOSTER FOR SECURED, HIGH SPEED AND MULTIPLE WAVELENGTH SERVICES IN OPTICAL COMMUNICATION SYSTEMS USING WDM AND QUAD-SINGLE FORWARD AND TRI BACKWARD PUMPING TECHNIQUE

2021 ◽  
Vol 5 (12) ◽  
Author(s):  
S. Semmalar ◽  
S. Malarkkan
Keyword(s):  
Wavelength Division Multiplexing ◽  
Optical Communication ◽  
Communication Systems ◽  
High Speed ◽  
Optical Power ◽  
Fiber Amplifier ◽  
Signal Power ◽  
Erbium Doped Fiber Amplifier ◽  
Output Optical Power ◽  
Wavelength Division

Proposed the EDFA and EYCDFA power booster (Erbium Doped Fiber Amplifier- Erbium ytterbium co doped fiber amplifier) with quad pumping for high speed and multi wavelength services in an optical communication. The proposed EDFA and EYCDFA power booster with WDM(Wavelength division multiplexing) simulated by dual forward and Backward pumping, Dual-backward pumping, Tri-single forward and dual backward pumping and Quadsingle forward and tri-backward pumping with respect to Pump power and fiber Length. The parameters Input Optical power, Output Optical power, Forward Signal power, Backward Signal power measured and determined the speed of transmission in all types of pumping methods. From that the proposed EDFA- ans EYCDFA power booster with WDM quad pumping is the best suitable for secured high speed optical telecommunication systems. The results shown in Quad pumping Output optical power is maximum 25.2dB and optimum spectral forward Signal power is 30.5dBm and very less spectral optical backward signal power of -25.4dBm with Length 5m

Comparative Analysis of High Speed 20/20 Gbps OTDM-PON, WDM-PON and TWDM-PON for Long-Reach NG-PON2

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Meet Kumari ◽  
Reecha Sharma ◽  
Anu Sheetal
Keyword(s):  
Wavelength Division Multiplexing ◽  
High Speed ◽  
Optical Network ◽  
Access Network ◽  
Cost Effective ◽  
Input Power ◽  
Passive Optical Network ◽  
Wavelength Division ◽  
Transmission Distance ◽  
Wdm Pon

AbstractNowadays, bandwidth demand is enormously increasing, that causes the existing passive optical network (PON) to become the future optical access network. In this paper, next generation passive optical network 2 (NG-PON2) based, optical time division multiplexing passive optical network (OTDM-PON), wavelength division multiplexing passive optical network (WDM-PON) and time & wavelength division multiplexing passive optical network (TWDM-PON) systems with 20 Gbps (8 × 2.5 Gbps) downstream and 20 Gbps (8 × 2.5 Gbps) upstream capacity for eight optical network units has been proposed. The performance has been compared by varying the input power (−6 to 27 dBm) and transmission distance (10–130 km) in terms of Q-factor and optical received power in the presence of fiber noise and non-linearities. It has been observed that TWDM-PON outperforms OTDM-PON and WDM-PON for high input power and data rate (20/20 Gbps). Also, TWDM-PON shows its superiority for long-reach transmission up to 130 km, which is a cost-effective solution for future NG-PON2 applications.

scholarly journals Receiver Integration with Arrayed Waveguide Gratings toward Multi-Wavelength Data-Centric Communications and Computing

2020 ◽  
Vol 10 (22) ◽  
pp. 8205
Author(s):  
Yoshiyuki Doi ◽  
Toshihide Yoshimatsu ◽  
Yasuhiko Nakanishi ◽  
Satoshi Tsunashima ◽  
Masahiro Nada ◽  
...  
Keyword(s):  
Wavelength Division Multiplexing ◽  
High Speed ◽  
Baud Rate ◽  
Arrayed Waveguide Gratings ◽  
Wavelength Division ◽  
Integrated Devices ◽  
Multi Wavelength ◽  
Integration Techniques ◽  
Waveguide Gratings ◽  
Arrayed Waveguide

This paper reviews receivers that feature low-loss multimode-output arrayed waveguide gratings (MM-AWGs) for wavelength division multiplexing (WDM) as well as hybrid integration techniques with high-speed throughput of up to 100 Gb/s and beyond. A design of optical coupling between higher-order multimode beams and a photodiode for a flat-top spectral shape is described in detail. The WDM photoreceivers were fabricated with different approaches. A 10-Gb/s photoreceiver was developed for a 1.25-Gb/s baud rate and assembled for eight-channel WDM by mechanical alignment. A receiver with 40-Gb/s throughput was built by using visual alignment for a 10-Gb/s baud rate and four-channel WDM. A 100-Gb/s receiver assembled by active alignment with a four-channel by 25-Gb/s baud rate is the basis for beyond-100 Gb/s and future multi-wavelength integrated devices toward data-centric communications and computing.

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