Silicon-based optical links using novel direct detection, coherent detection and dual polarization methods for new generation transport architectures

2019 ◽  
Vol 450 ◽  
pp. 48-60 ◽  
Author(s):  
Md Ghulam Saber ◽  
Gemma Vall-Llosera ◽  
David Patel ◽  
Alireza Samani ◽  
Rui Li ◽  
...  
Keyword(s):  
Direct Detection ◽  
Coherent Detection ◽  
Dual Polarization ◽  
Optical Links ◽  
Silicon Based ◽  
New Generation

scholarly journals Accurate Power-Efficient Format-Scalable Multi-Parallel Optical Digital-to-Analogue Conversion

Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 38
Author(s):  
Moshe Nazarathy ◽  
Ioannis Tomkos
Keyword(s):  
Energy Efficiency ◽  
Direct Detection ◽  
Coherent Detection ◽  
Performance Limits ◽  
Optical Modulators ◽  
Analog To Digital ◽  
Power Efficient ◽  
Optical Signals ◽  
Digital To Analog Converters ◽  
Optical Analog

In optical transmitters generating multi-level constellations, optical modulators are preceded by Electronic Digital-to-Analog-Converters (eDAC). It is advantageous to use eDAC-free Optical Analog to Digital Converters (oDAC) to directly convert digital bitstreams into multilevel PAM/QAM optical signals. State-of-the-art oDACs are based on Segmented Mach-Zehnder-Modulators (SEMZM) using multiple modulation segments strung along the MZM waveguides to serially accumulate binary-modulated optical phases. Here we aim to assess performance limits of the Serial oDACs (SEMZM) and introduce an alternative improved Multi-Parallel oDAC (MPoDAC) architecture, in particular based on arraying multiple binary-driven MZMs in parallel: Multi-parallel MZM (MPMZM) oDAC. We develop generic methodologies of oDAC specification and optimization encompassing both SEMZM and MPMZM options in Direct-Detection (DD) and Coherent-Detection (COH) implementations. We quantify and compare intrinsic performance limits of the various serial/parallel DD/COH subclasses for general constellation orders, comparing with the scant prior-work on the multi-parallel option. A key finding: COH-MPMZM is the only class synthesizing ‘perfect’ (equi-spaced max-full-scale) constellations while maximizing energy-efficiency-SEMZM/MPMZM for DD are less accurate when maximal energy-efficiency is required. In particular, we introduce multiple variants of PAM4|8 DD and QAM16|64 COH MPMZMs, working out their accuracy vs. energy-efficiency-and-complexity tradeoffs, establishing their format-reconfigurability (format-flexible switching of constellation order and/or DD/COH).

scholarly journals Progress on Nanomaterials for Photoelectrochemical Solar Cells: from Titania to Perovskites

2019 ◽  
Vol 125 ◽  
pp. 14015
Author(s):  
Indriana Kartini
Keyword(s):  
Solar Cells ◽  
Short Review ◽  
Natural Dyes ◽  
Pec Solar Cells ◽  
Structure Of Nanomaterials ◽  
Photoelectrochemical Solar Cells ◽  
And Performance ◽  
The One ◽  
Silicon Based ◽  
New Generation

Solar cells have been the queen of alternative renewable energy for the earth. From silicon-based solar cells to the new generation of perovskite-based solar cells, the choice and performance of the materials of the corresponding cells are still the focus of research interest. Amongst, photoelectrochemical (PEC) solar cells trigger the use and exploration of nanomaterials to boost their cell’s performance. This short review focus on the development of nanomaterials used for PEC, from nanoparticles to the one-dimensional titanium dioxide (titania) such as nanofibers and nanotubes, as well as the hybrid system with the perovskite halide. The search for light-harvesting materials is also included especially natural dyes. The review ends with a strategy to marry the natural dyes' potential with the sophisticated structure of nanomaterials to result in an efficient natural dyes PEC solar cells.

scholarly journals Analytical results on channel capacity in uncompensated optical links with coherent detection: erratum

2012 ◽  
Vol 20 (17) ◽  
pp. 19610 ◽  
Author(s):  
G. Bosco ◽  
P. Poggiolini ◽  
A. Carena ◽  
V. Curri ◽  
F. Forghieri
Keyword(s):  
Channel Capacity ◽  
Coherent Detection ◽  
Optical Links ◽  
Analytical Results

Performance Analysis of Digital Modulation for Coherent Detection of OFDM Scheme on Radio over Fiber System

2016 ◽  
Vol 6 (3) ◽  
pp. 1086 ◽  
Author(s):  
Fauza Khair ◽  
Fakhriy Hario P ◽  
I Wayan Mustika ◽  
Budi Setiyanto
Keyword(s):  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Fiber Length ◽  
Direct Detection ◽  
Symbol Error Rate ◽  
Radio Over Fiber ◽  
Coherent Detection ◽  
Fiber System ◽  
Digital Modulation ◽  
Modulation Formats

Radio over fiber (RoF) system with the coherent detection offers high linearity for the transparent transport of high-frequency microwave signals, and better receiver sensitivity compared with intensity-modulated direct detection systems. The purpose of this paper is to analyze the performance of digital modulation for coherent detection of orthogonal frequency division multiplexing (OFDM) scheme on RoF system at 10 Gbps up to 100 km fiber length. The results show that coherent detection of OFDM-RoF system with 16 quadrature amplitude modulation (16-QAM) has the value of  bit error rate (BER) and the symbol error rate (SER) is very low and its constellation is better compared with other modulation formats (4-QAM, quadrature phase shift keying (QPSK), 8-PSK and 16-PSK), which BER 16-QAM is 0.053 and SER is 15.7%. The results also show that BER value of 4-QAM and QPSK relatively similar to fiber length variations. In general, an increasing value of the BER and SER for each modulation format are almost equal to the fiber length of 60-70 km (Region I and II). However, there is a significant increase in the value of BER in fiber length of 80-100 km (Region III. A and III. B) for the modulation of 4-QAM, QPSK, 8-PSK, and 16-PSK.

scholarly journals Green and scalable synthesis of nanocrystalline kuramite

2019 ◽  
Vol 10 ◽  
pp. 2073-2083
Author(s):  
Andrea Giaccherini ◽  
Giuseppe Cucinotta ◽  
Stefano Martinuzzi ◽  
Enrico Berretti ◽  
Werner Oberhauser ◽  
...  
Keyword(s):  
High Energy ◽  
Production Costs ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scalable Synthesis ◽  
Silicon Based ◽  
New Generation ◽  
Potential Pollution ◽  
X Ray Absorption

The new generation of solar cells aims to overcome many of the issues created by silicon-based devices (e.g., decommissioning, flexibility and high-energy production costs). Due to the scarcity of the resources involved in the process and the need for the reduction of potential pollution, a greener approach to solar cell material production is required. Among others, the solvothermal approach for the synthesis of nanocrystalline Cu–Sn–S (CTS) materials fulfils all of these requirements. The material constraints must be considered, not only for the final product, but for the whole production process. Most works reporting the successful synthesis of CTS have employed surfactants, high pressure or noxious solvents. In this paper, we demonstrate the synthesis of nanocrystalline kuramite by means of a simpler, greener and scalable solvothermal synthesis. We exploited a multianalytical characterization approach (X-ray diffraction, extended X-ray absorption fine structure, field emission scanning electron microscopy, Raman spectroscopy and electronic microprobe analysis (EMPA)) to discriminate kuramite from other closely related polymorphs. Moreover, we confirmed the presence of structural defects due to a relevant antisite population.

Microsensors for physical signals: Principles, device design, and fabrication technologies

1996 ◽  
Vol 74 (S1) ◽  
pp. 115-130 ◽  
Author(s):  
Arokia Nathan
Keyword(s):  
Integrated Circuit ◽  
Computer Aided Design ◽  
Electrical Signal ◽  
Single Chip ◽  
Research Activity ◽  
Rapid Pace ◽  
Silicon Based ◽  
Aided Design ◽  
New Generation ◽  
Physical And Chemical

Microsensors are miniaturized devices, fabricated using silicon-based and related technologies, that convert input physical and chemical signals into an output electrical signal. The key driving force in microsensor research has been the integrated circuit (IC) and micromachining technologies. The latter, in particular, is fueling tremendous activity in micro-electromechanical systems (MEMS). In terms of technology and design tools, MEMS is at a stage where microelectronics was 30 years ago and is expected to evolve at an equally rapid pace. The synergy between the IC, micromachining, and integrated photonics technologies can potentially spawn a new generation of microsystems that will feature a unique marriage of microsensor, signal-conditioning and -processing circuitry, micromechanics, and optomechanics possibly on a single chip. In this paper, the physical transduction principles, materials considerations, process-fabrication technologies, and computer-aided-design (CAD) tools will be reviewed along with pertinent examples drawn from our microsensor research activity at the Microelectronics Laboratory, University of Waterloo.

Simulation of microwave optical links and proof of noise figure lower than electrical losses

2010 ◽  
Vol 2 (6) ◽  
pp. 497-503 ◽  
Author(s):  
Anne-Laure Billabert ◽  
Mourad Chtioui ◽  
Christian Rumelhard ◽  
Catherine Algani ◽  
Mehdi Alouini ◽  
...  
Keyword(s):  
Noise Figure ◽  
Direct Detection ◽  
Impedance Matching ◽  
Electrical Network ◽  
Simulation Tool ◽  
Unusual Behavior ◽  
Optical Links ◽  
Operation Conditions ◽  
Laser Dynamics ◽  
Theoretical Predictions

The operation of a microwave photonic link is thoroughly investigated both theoretically and experimentally. To this aim, we have developed a simulation tool based on an accurate physical model embedded in a radio frequency (RF) chain simulator. The theoretical predictions are tested on an intensity modulation-direct detection (IMDD) link we have specifically developed to this purpose. Our simulation tool takes into account both optical and electrical characteristics of the link components including the laser dynamics and impedance matching networks. It thus enables an accurate understanding of the different physical and electrical phenomena governing the link's performances even under unusual operation conditions. Specifically, we were able to isolate an unusual behavior and to confirm it experimentally. It is thereby clear that the noise figure of a microwave optical link can be lower than the electrical losses, such as a mismatched output passive electrical network. This state is reached when the optical losses are high enough and when the link's output impedance is mismatched, too.

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