scholarly journals Quantum dash multi-wavelength lasers for Tbit/s coherent communications and 5G wireless networks

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Zhenguo Lu ◽  
Jiaren Liu ◽  
Youxin Mao ◽  
Khan Zeb ◽  
Guocheng Liu ◽  
...  
Keyword(s):  
High Speed ◽  
High Capacity ◽  
National Research Council ◽  
Modulation Formats ◽  
Quantum Dash ◽  
Optical Modes ◽  
Multi Wavelength ◽  
Dfb Laser ◽  
Technical Specifications ◽  
And Performance

AbstractWe report on the design, growth, fabrication, and performance of InAs/InP quantum dash (QD) multi-wavelength lasers (MWLs) developed by the National Research Council (NRC) Canada. The key technical specifications investigated include optical and RF beating spectra, relative intensity noise (RIN), and optical phase noise of each individual wavelength channel. Data bandwidth transmission capacity of 5.376 Tbit/s and 10.8 Tbit/s respectively in the PAM-4 and 16-QAM modulation formats are demonstrated using only a single C-band QD 34.2-GHz MWL chip. We have also developed a monolithic InAs/InP QD dual-wavelength (DW) DFB laser as a compact optical beat source to generate millimeter-wave (MMW) signals. Due to the common cavity, highly coherent and correlated optical modes with optical linewidth as low as 15.83 kHz, spectrally pure MMW signals around 46.8 GHz with a linewidth down to 26.1 kHz were experimentally demonstrated. By using this QD DW-DFB laser, a one GBaud (2 Gbps) MMW over-fiber transmission link is demonstrated with PAM-4 signals. The results show that the demonstrated device is suitable for high speed high capacity MMW fiber-wireless integrated fronthaul of 5G networks.

scholarly journals Quantum dot multi-wavelength lasers for Tbit/s coherent communications and 5G wireless networks -INVITED

2020 ◽  
Vol 238 ◽  
pp. 01003
Author(s):  
Z.G. Lu ◽  
J.R. Liu ◽  
Y.X. Mao ◽  
K. Zeb ◽  
G.C. Liu ◽  
...  
Keyword(s):  
Quantum Dot ◽  
High Speed ◽  
High Capacity ◽  
Modulation Formats ◽  
Qam Modulation ◽  
Optical Modes ◽  
Multi Wavelength ◽  
Dfb Laser ◽  
Technical Specifications ◽  
Transmission Link

We will present the design, growth, fabrication, electronic control and packaging of the InAs/InP quantum dot (QD) multi-wavelength lasers (MWLs) developed by AEP of NRC in Canada. Their key technical specifications include L-I-V curves, optical and RF beating spectra, relative intensity noise (RIN), and optical phase noise of each individual wavelength channel, as well as timing jitter are investigated. Data bandwidth transmission capacity of 5.376 Tbit/s and 10.3 Tbit/s respectively in the PAM-4 and 16-QAM modulation formats are demonstrated by only using a single QD MWL chip. We have also developed a novel monolithic InAs/InP QD dual-wavelength (DW) DFB laser as a compact optical beat source to generate millimeter-wave (MMW) signals. Because of using a common cavity, highly coherent and correlated optical modes with optical linewidth as low as 15.83 kHz, spectrally pure MMW signals around 46.8 GHz with a linewidth down to 26.1 kHz were experimentally demonstrated. By using this QD DW-DFB laser, a 1Gbaud (2Gbps) MMW over-fiber transmission link is demonstrated with PAM-4 signals. The results show that the demonstrated device is suitable for high speed high capacity MMW fiber-wireless integrated fronthaul of 5G networks.

Analysis of Four Wave Mixing In Ultra Dense WDM-Hybrid Optical Amplifier Systems

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Navjot Singh ◽  
Mahendra Kumar ◽  
Ashu Verma
Keyword(s):  
Wavelength Division Multiplexing ◽  
High Speed ◽  
High Capacity ◽  
Optical Amplifier ◽  
Four Wave Mixing ◽  
Wave Mixing ◽  
Gain Bandwidth ◽  
Wavelength Division ◽  
Dense Wdm ◽  
And Performance

AbstractAmplification through hybrid optical amplifiers (HOAs) is a propitious and proficient technology for high speed and high capacity dense wavelength-division-multiplexing (DWDM) systems. HOAs are intended to improve system reach and to accomplish wide gain bandwidth with enhanced flatness of gain. In this work, an ultradense 16 channel WDM system is demonstrated and performance of diverse hybrid amplifiers is evaluated in terms of output power, Q-factor, gain flatness and BER. Spacing among the WDM channels is 25 GHz in order to make system bandwidth efficient and scrutinized its effect on four wave mixing (FWM) in case of EDFA-EDFA, Raman-EDFA and SOA-EDFA. It is observed that SOA-EDFA is more and Raman-EDFA is less prone to FWM. Moreover, for distance 20 Km–140 Km, Raman-EDFA is optimal configuration for amplification and from 150 Km–200  Km, SOA-EDFA shows better performance. For prolonged link lengths such as beyond 200  Km, EDFA-EDFA is a right hybrid amplifier. In order to achieve maximum gain flatness in proposed architecture, EDFA-EDFA is recommended to use.

scholarly journals Spatially Resolved Experimental Modal Analysis on High-Speed Composite Rotors Using a Non-Contact, Non-Rotating Sensor

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4705
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Juergen Czarske ◽  
...  
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Fiber Reinforced ◽  
Structural Dynamic ◽  
Spatially Resolved ◽  
Glass Fiber Reinforced ◽  
Vibration Responses ◽  
And Performance

Due to their lightweight properties, fiber-reinforced composites are well suited for large and fast rotating structures, such as fan blades in turbomachines. To investigate rotor safety and performance, in situ measurements of the structural dynamic behaviour must be performed during rotating conditions. An approach to measuring spatially resolved vibration responses of a rotating structure with a non-contact, non-rotating sensor is investigated here. The resulting spectra can be assigned to specific locations on the structure and have similar properties to the spectra measured with co-rotating sensors, such as strain gauges. The sampling frequency is increased by performing consecutive measurements with a constant excitation function and varying time delays. The method allows for a paradigm shift to unambiguous identification of natural frequencies and mode shapes with arbitrary rotor shapes and excitation functions without the need for co-rotating sensors. Deflection measurements on a glass fiber-reinforced polymer disk were performed with a diffraction grating-based sensor system at 40 measurement points with an uncertainty below 15 μrad and a commercial triangulation sensor at 200 measurement points at surface speeds up to 300 m/s. A rotation-induced increase of two natural frequencies was measured, and their mode shapes were derived at the corresponding rotational speeds. A strain gauge was used for validation.

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.

scholarly journals Prototype Design and Experimental Evaluation of Autonomous Collaborative Communication System for Emerging Maritime Use Cases

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3871
Author(s):  
Jiri Pokorny ◽  
Khanh Ma ◽  
Salwa Saafi ◽  
Jakub Frolka ◽  
Jose Villa ◽  
...  
Keyword(s):  
Communication System ◽  
Autonomous Vehicles ◽  
High Speed ◽  
High Capacity ◽  
Workplace Safety ◽  
Unmanned Vehicles ◽  
Use Cases ◽  
Automated Systems ◽  
Collaborative Communication ◽  
Wide Range

Automated systems have been seamlessly integrated into several industries as part of their industrial automation processes. Employing automated systems, such as autonomous vehicles, allows industries to increase productivity, benefit from a wide range of technologies and capabilities, and improve workplace safety. So far, most of the existing systems consider utilizing one type of autonomous vehicle. In this work, we propose a collaboration of different types of unmanned vehicles in maritime offshore scenarios. Providing high capacity, extended coverage, and better quality of services, autonomous collaborative systems can enable emerging maritime use cases, such as remote monitoring and navigation assistance. Motivated by these potential benefits, we propose the deployment of an Unmanned Surface Vehicle (USV) and an Unmanned Aerial Vehicle (UAV) in an autonomous collaborative communication system. Specifically, we design high-speed, directional communication links between a terrestrial control station and the two unmanned vehicles. Using measurement and simulation results, we evaluate the performance of the designed links in different communication scenarios and we show the benefits of employing multiple autonomous vehicles in the proposed communication system.

Image-Based Versus Signal-Based Sensors for Machine Fault Detection and Isolation

2014 ◽  
Author(s):  
Heshan Fernando ◽  
Vedang Chauhan ◽  
Brian Surgenor
Keyword(s):  
Fault Detection ◽  
High Speed ◽  
Fault Isolation ◽  
Video Data ◽  
Fault Detection And Isolation ◽  
Single Camera ◽  
Multiple Faults ◽  
Multiple Sensors ◽  
Machine Fault ◽  
And Performance

This paper presents the results of a comparative study that investigated the use of image-based and signal-based sensors for fault detection and fault isolation of visually-cued faults on an automated assembly machine. The machine assembles 8 mm circular parts, from a bulk-supply, onto continuously moving carriers at a rate of over 100 assemblies per minute. Common faults on the machine include part jams and ejected parts that occur at different locations on the machine. Two sensor systems are installed on the machine for detecting and isolating these faults: an image-based system consisting of a single camera and a signal-based sensor system consisting of multiple greyscale sensors and limit switches. The requirements and performance of both systems are compared for detecting six faults on the assembly machine. It is found that both methods are able to effectively detect the faults but they differ greatly in terms of cost, ease of implementation, detection time and fault isolation capability. The conventional signal-based sensors are low in cost, simple to implement and require little computing power, but the installation is intrusive to the machine and readings from multiple sensors are required for faster fault detection and isolation. The more sophisticated image-based system requires an expensive, high-resolution, high-speed camera and significantly more processing power to detect the same faults; however, the system is not intrusive to the machine, fault isolation becomes a simpler problem with video data, and the single camera is able to detect multiple faults in its field of view.

DFB Lasers with Tilted Waveguide for Multi-Wavelength Generation

2007 ◽  
Vol 31 ◽  
pp. 36-38 ◽  
Author(s):  
Lip Fah Chong ◽  
Jing Hua Teng ◽  
Ee Leong Lim ◽  
Norman Soo Seng Ang ◽  
J.R. Dong ◽  
...  
Keyword(s):  
Single Mode ◽  
Distributed Feedback ◽  
Couple Mode ◽  
Threshold Condition ◽  
Couple Mode Theory ◽  
Gain Margin ◽  
Ridge Waveguides ◽  
Multi Wavelength ◽  
Dfb Laser ◽  
Lasing Frequency

In this paper, we present the theoretical investigation of index-coupled distributed feedback (DFB) laser with tilted single mode ridge waveguides. By tilting part of the ridge waveguide in various degrees, DFB laser with manifold effective grating periods can be realized. The structure is analyzed using couple mode theory in matrix form based on threshold analysis. Important parameters of DFB laser like resonant frequency and threshold gains are obtained by solving the eigen-equation. The results indicate not only that the lasing frequency is modulated by the waveguide titling angle, but also large Gain Margin (GM) can be achieved at the threshold condition which enhance the stable single mode operation in index-coupled DFB laser.

The Design and Implementation of ECC High-Speed Encryption Engine Based on FPGA

2012 ◽  
Vol 459 ◽  
pp. 544-548 ◽  
Author(s):  
Wei Liang ◽  
Jian Bo Xu ◽  
Wei Hong Huang ◽  
Li Peng
Keyword(s):  
Data Transmission ◽  
High Speed ◽  
Lower Cost ◽  
Low Cost ◽  
Rapid Development ◽  
Security Technology ◽  
Multiplication Algorithm ◽  
Secure Data Transmission ◽  
And Performance ◽  
Computation Speed

Network security technology ensures secure data transmission in network. Meanwhile, it brings extra overhead of security system in terms of cost and performance, which seriously affects the rapid development of existing high-speed encryption systems. The existing encryption technology cannot meet the demand of high security, low cost and high real-time. For solving above problems, an ECC encryption engine architecture based on scalable public key cipher and a high-speed configurable multiplication algorithm are designed. The algorithm was tested on FPGA platform and the experiment results show that the system has better computation speed and lower cost overhead. By comparing with other systems, our system has benefits in terms of hardware overhead and encryption time ratio

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