INFLUENCE OF EXTINCTION RATIO ON THE PERFORMANCE OF RZ-ODPASK MODULATION FORMAT

2009 ◽  
Vol 23 (11) ◽  
pp. 2479-2489
Author(s):  
XIAOJUN LI ◽  
AIJUN WEN ◽  
ZENGJI LIU ◽  
TAO SHANG
Keyword(s):  
Single Channel ◽  
Chromatic Dispersion ◽  
Extinction Ratio ◽  
Optical Fields ◽  
Analytical Methodology ◽  
Modulation Formats ◽  
Modulation Format ◽  
Fiber Nonlinearity ◽  
Shift Keying ◽  
Phase Amplitude

The influence of extinction ratio (ER) on the performance of 120 Gbps return-to-zero octal differential phase-amplitude-shift keying (RZ-ODPASK) modulation format in single-channel transmission is investigated. Based on the modulation and demodulation schemes, the structures of RZ-ODPASK transmitter and receiver are presented; and expressions for the output optical fields and electrical currents of amplitude and phase tributaries are analytically acquired. As ER is a tradeoff for good performance of the two tributaries, the optimal ER for back-to-back configuration is theoretically derived as 2.32 dB for the first time, which is verified by simulation. Then the tolerances to residual chromatic dispersion (CD) and fiber nonlinearity of RZ-ODPASK transmission are numerically studied, respectively. The results indicate that phase tributary is more robust against both dispersion and nonlinearity impairment than the amplitude tributary. To balance the performance of the two tributaries, curves of the optimal ER values with the change of residual CD and fiber nonlinearity are also obtained, respectively. The results can be useful for the design of RZ-ODPASK systems; in the meantime, the analytical methodology described in this paper is applicable to other multilevel RZ-DPASK modulation formats.

400-Gb/s Modulation-Format-Independent Single-Channel Transmission With Chromatic Dispersion Precompensation Based on OAWG

2010 ◽  
Vol 22 (12) ◽  
pp. 905-907 ◽  
Author(s):  
David J. Geisler ◽  
Nicolas K. Fontaine ◽  
Ryan P. Scott ◽  
Tingting He ◽  
Loukas Paraschis ◽  
...  
Keyword(s):  
Single Channel ◽  
Chromatic Dispersion ◽  
Modulation Format

Performance Evaluation of Proposed WDM Optical Link Using EDFA and FBG Combination

2019 ◽  
Vol 40 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Deepti Ahlawat ◽  
Payal Arora ◽  
Suresh Kumar
Keyword(s):  
Wavelength Division Multiplexing ◽  
Chromatic Dispersion ◽  
Fiber Amplifier ◽  
Q Factor ◽  
Wavelength Band ◽  
Modulation Formats ◽  
Erbium Doped Fiber Amplifier ◽  
Wavelength Division ◽  
Modulation Format ◽  
Erbium Doped

Abstract Analysis of wavelength division multiplexing (WDM) system utilizing erbium-doped fiber amplifier (EDFA) has been carried out by many researchers. In this paper, the performance analysis of 8-channel WDM system utilizing EDFA and fiber Bragg grating (FBG) combination is carried out in a wavelength band 1546–1552 nm at 10 Gbps. The performance of three apodization functions (Uniform, Gaussian and Tanh) of FBG is compared using return-to-zero (RZ) and non-return-to-zero modulation formats at fiber lengths 50, 60, 70 and 80 km. Also, the performance of FBG is compared for both aspects: with chirp and without chirp for grating lengths 5–10 mm. The Gaussian apodized and linearly chirped FBG outperformed the other two in compensating chromatic dispersion. Optimum values of Q-factor are also obtained using linearly chirped FBG with RZ modulation format at 10 mm of grating length.

scholarly journals Frequency-Octupling Millimeter-Wave Optical Vector Signal Generation via an I/Q Modulator-Based Sagnac Loop

Symmetry ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 84
Author(s):  
Zhixian Yang ◽  
Kun Qu ◽  
Xiang Liu
Keyword(s):  
Millimeter Wave ◽  
Wave Vector ◽  
Chromatic Dispersion ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Optical Fields ◽  
Wave Nature ◽  
Shift Keying ◽  
Frequency Octupling ◽  
Vector Signal

A new method for generating frequency-octupling millimeter-wave (mm-wave) vector signals in optical fields via a Sagnac loop is proposed. In this scheme, two orthogonally polarized fourth order sidebands can be obtained through an integrated dual-polarization quadrature phase shift keying (DP-QPSK) modulator. The two optical sidebands are sent into an I/Q modulator-based Sagnac loop. The I/Q modulator is modulated by a 16QAM baseband signal. In the Sagnac loop, one of the sidebands is modulated by the baseband vector signal along one direction, and the other sideband is unmodulated along the opposite direction because the I/Q modulator has the traveling-wave nature. Thanks to this modulation property and the symmetrical structure of the Sagnac loop, a frequency-octupling mm-wave vector signal that is free from interband beating and fiber chromatic dispersion interference can be generated by the photodetector (PD). After simulating a 20 km single-mode fiber (SMF) transmission, the generated frequency-octupling vector signal was good in function.

Effect of Fiber Nonlinearity on the Performance of WDM Dual-Polarization Coherent Optical OFDM Systems

2014 ◽  
Vol 13 (9) ◽  
pp. 4943-4964 ◽  
Author(s):  
Bashar M. Ahmed ◽  
Raad S. Fyath
Keyword(s):  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
Single Channel ◽  
Ofdm Systems ◽  
Dual Polarization ◽  
Modulation Formats ◽  
Wavelength Division ◽  
Fiber Nonlinearity ◽  
Transmission Distance ◽  
High Spectral Efficiency

In recent years, there is increasing interest in using dual-polarization (DP) technique to enable future systems with at least 100 Gb/s rate per channel to operate over existing optical networks. The performance of these advanced systems can be enhanced further by using coherent optical orthogonal multiplexing (CO-OFDM) technique which offers high spectral efficiency and outstanding tolerance of fiber dispersion. This paper addresses the effect of fiber nonlinear optics on the performance of dual-polarization wavelength-division multiplexing (WDM) CO-OFDM systems operating with 100 Gb/s per channel. Different modulation formats, namely BPSK, QPSK and 16-QAM, are used. First, the performance of a single-channel system is investigated in the absence and presence of fiber nonlinearity. The results are compared with a conventional (single-polarization) system to identify the key role played by the DP technique. The investigation is then extended to WDM systems incorporating DP-OFDM technique. The results reveal that the effect of fiber nonlinearity can be reduced by using optimum transmitter laser power Popt. Further, the value of Popt is a function of transmission distance, number of multiplexed channels, and modulation formats. Popt of -11, -12, and -5 dBm is needed for a ten-channel DP system operating with BPSK, QPSK, and 16-QAM formats, respectively. Simulation results presented in this work are obtained using Opti System (version 11.1) which is a commercial software package

Performance Enhancement of Ultra High Capacity 2.5 Tbps DWDM System Using DCF and Optimized Modulation Format

2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Sooraj Parkash
Keyword(s):  
Performance Enhancement ◽  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
High Capacity ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Modulation Formats ◽  
Modulation Format ◽  
Point To Point ◽  
Dwdm System

AbstractThis paper successfully demonstrate point-to-point (P2P) 2.5 TB/s DWDM system in downstream for 100 wavelengths having 0.4 nm (50 GHz) channel spacing by using post-dispersion compensation scheme. Each channel is transmitting 25 GB/s data rate in down link. A 20 km dispersion compensating fiber (DCF) followed by 80 km standard single mode fiber (SSMF) which passes 20 times through fiber span for compensating the chromatic dispersion. The maximum reach of designed system is (100×20) 2,000 km. In this paper we also performed the comparison of different modulation formats such as NRZ, RZ and CRZ. It has been observed that CRZ modulation format can achieve BER as better as e

scholarly journals Numerical comparison between DPSK 33, DPSK 66 and duo binary in WOC system

2021 ◽  
Vol 23 (1) ◽  
pp. 247
Author(s):  
Mustafa H. Ali ◽  
Hazim M. Ali ◽  
Tariq A. Hassan
Keyword(s):  
Single Channel ◽  
Superior Performance ◽  
Duty Ratio ◽  
Numerical Comparison ◽  
Q Factor ◽  
Small Aperture ◽  
Modulation Formats ◽  
Great Loss ◽  
Aperture Diameter ◽  
Modulation Format

OWC systems have turned into a state-of-the-art technology because of their superior performance uniqueness and its innumerable characteristic as compared to its RF. One of the OWC application is inter-satellite wireless optical communication (Is-WOC), this framework can be improved by using different ways such as advanced modulation formats and aperture diameter. We demonstrate an analysis based on the aperture diameter effect in transmission of single channel with 40 Gb/s Is-WOC system using three different modulation methods, differential phase-shift keying (DPSK) with a duty ratio to 66% and 33% and duobinary. Choosing these three modulations from various modulation format is done depending on the advantage they provide where the DPSK gives to fiber nonlinearity a powerful robustness and less susceptible to SPM and XPM and for system requirements of dispersion compensation in duobinary, it provides higher chromatic dispersion tolerance mitigate. The result shows the effect of different transmitter aperture diameter (from 2 to 20 cm) for a constant distance 200 km accomplished by quality factor and minimum BER. We conclude there is a great loss in the small aperture diameter, even in the presence of best modulation format, therefore as the aperture diameter increase the Q-factor increase, but some increased rise is linear and the other is changing from linear to non-linear in a fixed Q-factor point equal to 5.63.

scholarly journals Investigation on Maximum Available Reach for Different Modulation Formats in WDM-PON Systems

2016 ◽  
Vol 53 (4) ◽  
pp. 66-75 ◽  
Author(s):  
I. Kurbatska ◽  
V. Bobrovs ◽  
S. Spolitis ◽  
P. Gavars ◽  
G. Ivanovs ◽  
...  
Keyword(s):  
Dispersion Compensation ◽  
Software Tool ◽  
Transmission Systems ◽  
Modulation Formats ◽  
Differential Phase Shift ◽  
Modulation Format ◽  
Differential Phase Shift Keying ◽  
Transmission Distance ◽  
Shift Keying ◽  
Optical Transmission Systems

Abstract Considering the growing demand for broadband of access networks, in the present paper we investigate various modulation formats as a way of increasing the performance of optical transmission systems. Non-return-to-zero (NRZ) on-off keying, return-to-zero (RZ) OOK, carrier suppressed RZ (CSRZ) OOK, duobinary (DB), NRZ differential phase shift keying (NRZDPSK), RZ-DPSK and CSRZ-DPSK formats are compared using the maximal achievable reach with bit error rate less than 10−9 as a criterion. Simulations are performed by using OptSim software tool. It is shown that using the transmission system without dispersion compensation the best results are shown by duobinary and CSRZ-OOK modulation formats, but with the system using dispersion compensating fiber (DCF) the longest transmission distance is achieved by RZ-DPSK modulation format. By investigating the influence of channel spacing for best-performed modulation formats, network reach decrease for transmission systems with DCF fiber has been observed due to channel crosstalk.

scholarly journals Efficient Modulation Formats for High Bit-Rate Fiber Transmission

2006 ◽  
Vol 16 (2) ◽  
pp. 17-26 ◽  
Author(s):  
A. García-Pérez ◽  
J. A. Andrade-Lucio ◽  
O. G. Ibarra-Manzano ◽  
E. Alvarado-Méndez ◽  
M. Trejo-Duran ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Communication Systems ◽  
Chromatic Dispersion ◽  
Polarization Mode Dispersion ◽  
Nonlinear Effects ◽  
Bit Rate ◽  
Modulation Formats ◽  
Modulation Format ◽  
Mode Dispersion ◽  
Advanced Modulation Formats

The topic of this report will deal with the study of advanced modulation formats for highspeed optical communication systems. Basically, the use of alternate polarization modulation (alP) is considered in order to reduce the inter-symbol interference (ISI) caused mainly by effects such as Chromatic Dispersion (CD), Polarization Mode Dispersion (PMD) and Nonlinear effects. The comparative analysis among the different formats is carried out by means of the obtaining of its different spectrums. A detailed analysis of these and their dependency to the modulation format that generates it is presented. The article presents numerical comparative analysis using commercial software VPI Maker Transmission, where the results obtained show that the formats of alternating polarization are the best results at the bit rate of 40 Gb/s per channel.

scholarly journals Asymmetric Ge/SiGe coupled quantum well modulators

Nanophotonics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1765-1773
Author(s):  
Yi Zhang ◽  
Jianfeng Gao ◽  
Senbiao Qin ◽  
Ming Cheng ◽  
Kang Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Quantum Well ◽  
Quantum Wells ◽  
High Speed ◽  
Low Voltage ◽  
Extinction Ratio ◽  
High Frequency Response ◽  
Modulation Format ◽  
Silicon Photonic ◽  
Coupled Quantum Well

Abstract We design and demonstrate an asymmetric Ge/SiGe coupled quantum well (CQW) waveguide modulator for both intensity and phase modulation with a low bias voltage in silicon photonic integration. The asymmetric CQWs consisting of two quantum wells with different widths are employed as the active region to enhance the electro-optical characteristics of the device by controlling the coupling of the wave functions. The fabricated device can realize 5 dB extinction ratio at 1446 nm and 1.4 × 10−3 electrorefractive index variation at 1530 nm with the associated modulation efficiency V π L π of 0.055 V cm under 1 V reverse bias. The 3 dB bandwidth for high frequency response is 27 GHz under 1 V bias and the energy consumption per bit is less than 100 fJ/bit. The proposed device offers a pathway towards a low voltage, low energy consumption, high speed and compact modulator for silicon photonic integrated devices, as well as opens possibilities for achieving advanced modulation format in a more compact and simple frame.

scholarly journals Systematic Performance Comparison of (Duobinary)-PAM-2,4 Signaling under Light and Strong Opto-Electronic Bandwidth Conditions

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 81
Author(s):  
Ramón Gutiérrez-Castrejón ◽  
Md Ghulam Saber ◽  
Md Samiul Alam ◽  
Zhenping Xing ◽  
Eslam El-Fiky ◽  
...  
Keyword(s):  
Optical Networks ◽  
High Speed ◽  
Performance Comparison ◽  
Sampling Point ◽  
Bit Rate ◽  
Performance Limits ◽  
Specific System ◽  
Rate System ◽  
Modulation Formats ◽  
Modulation Format

We present a systematic comparison of PAM-2 (NRZ), Duobinary-PAM-2, PAM-4, and Duobinary-PAM-4 (duo-quaternary) signaling in the context of short-reach photonic communications systems using a Mach–Zehnder modulator as transmitter. The effect on system performance with a relaxed and constrained system’s opto-electronic bandwidth is analyzed for bit rates ranging from 20 to 116 Gb/s. In contrast to previous analyses, our approach employs the same experimental and simulation conditions for all modulation formats. Consequently, we were able to confidently determine the performance limits of each format for particular values of bit rate, system bandwidth, transmitter chirp, and fiber dispersion. We demonstrate that Duobinary-PAM-4 is a good signaling choice only for bandwidth-limited systems operating at relatively high speed. Otherwise, PAM-4 represents a more sensible choice. Moreover, our analysis put forward the existence of transition points: specific bit rate values where the BER versus bit rate curves for two different formats cross each other. They indicate the bit rate values where, for specific system conditions, switching from one modulation to another guarantees optimum performance. Their existence naturally led to the proposal of a format-selective transceiver, a component that, according to network conditions, operates with the most adequate modulation format. Since all analyzed modulations share similar implementation details, signaling switching is achieved by simply changing the sampling point and threshold count at the receiver, bringing flexibility to IM/DD-based optical networks.

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