Nonlinear digital compensation for spatial multiplexing systems

We review the latest advances on digital backward-propagation for the compensation of inter-channel nonlinear interference in spatial- and wavelength-multiplexed systems. Different solution methods of the multimode Schrödinger equation are compared for challenging linear mode coupling and differential mode delay conditions, highlighting the significant relaxation of the step size requirements provided by the separate-channels approach

MMF Design using Evolutionary Algorithms

We review the latest advances on the design of few-mode fibres guiding up to 21 polarisation modes with low differential mode delay over the C-band. suitable for long-haul transmission

Antimicrobial resistance and antimicrobial use animal monitoring policies in Europe: Where are we?

The World Health Organization has recognized antimicrobial resistance as one of the top three threats to human health. Any use of antibiotics in animals will ultimately affect humans and vice versa. Appropriate monitoring of antimicrobial use and resistance has been repeatedly emphasized along with the need for global policies. Under the auspices of the European Union research project, EFFORT, we mapped antimicrobial use and resistance monitoring programs in ten European countries. We then compared international and European guidelines and policies. In resistance monitoring, we did not find important differences between countries. Current resistance monitoring systems are focused on food animal species (using fecal samples). They ignore companion animals. The scenario is different for monitoring antibiotics use. Recently, countries have tried to harmonize methodologies, but reporting of antimicrobial use remains voluntary. We therefore identified a need for stronger policies

Optimization of 125-mu m Heterogeneous Multi-Core Fibre Design Using Artificial Intelligence

We propose an automated heterogeneous trench-assisted multi-core fibre (MCF) design method. This method uses neural networks to speed up coating loss estimation by ∼ 10^{6} times and using particle swarm optimization (PSO) algorithm to explore the optimal MCF design under various objectives and properties constraints. The latter reduces the permutation evaluations by ten orders of magnitude compared with the brute force method. The artificial intelligence (AI)-based method is used to design MCFs on two objectives: minimizing crosstalk (XT) and maximizing effective mode area ( A_{eff} ). By optimizing XT with different A_{eff} and cutoff wavelength constraints combinations for 6-core fibres, we achieved −92.1 dB/km ultra-low XT for C+L band fibre and −64 dB/km for E+S+C+L-band fibre. Meanwhile, we explored the upper limit of A_{eff} given different bandwidth constraints resulting in a 6.82 relative core multiplicity factor. We performed capacity analysis of fibres for two transmission lengths. It is shown that bandwidth is the dominant factor while the increase brought by A_{eff} and the penalty caused by XT are relevantly small. Our fibres exceed the cutoff-limited capacity of the 7-core fibre in literature by 35.1% and 84.8% for 1200 km and 6000 km transmission respectively

Mach-Zehnder FOPA for Dual Polarization Wavelength-Division-Multiplexed 100G Signal Amplification

We demonstrate amplification of 17x100 GHz-spaced channel in C-band by a PI-FOPA based on Mach-Zehnder architecture with net gain >10 dB and confirmed its robustness over time. A commercial 100G-PDM-QPSK transponder was used to measure/compare the bit-error-rate versus received power with a commercial EDFA

Digital Back Propagation via Sub-band Processing in Spatial Multiplexing Systems

An advanced digital backward-propagation (DBP) method using a separate-channels approach (SCA) is investigated for the compensation of inter-channel nonlinearities in spatial- and wavelength-multiplexed systems. Compared to the conventional DBP, intra- and inter-mode cross-phase modulation can be efficiently compensated by including the effect of the inter-channel walk-off in the nonlinear step of the split-step Fourier method. We found that the SCA-DBP relaxes the step size requirements by a factor of 10, while improving performance by 0.8 dB for large walk-off and strong linear coupling. For the first time, it is shown that in spatial multiplexed systems transmission performance can be improved by sub-band processing of back propagated channels

Design Optimization of Uncoupled Six-core Fibers in Standard Cladding Diameter Using Artificial Intelligence

We report on ultra-wide-band and long-haul compatible 125µm six-core trench-assisted fiber designs. The AI-optimization process considers crosstalk, effective area, and bandwidth. We show that homogeneous cores can lead to low complexity yet high capacity fiber

Experimental Demonstration of a Simplified SOA Nonlinearity Mitigation scheme

We experimentally demonstrated a digital learned-filter mitigation scheme for semiconductor optical amplifier-induced nonlinear distortion of single-polarisation 32 GBd 16QAM and 64QAM signals in a back-to-back configuration

Advances on Bacterial and Fungal Biofilms for the Production of Added-Value Compounds

Simple Summary The production of bio-based materials, including organic acids, antibiotics, enzymes, ethanol, and hydrogen, is generally done by the cultivation of suspended cells rather than using immobilized cells. However, several studies suggest the application of productive biofilms as a reliable alternative for biocatalysis, with many advantages over suspended-growth systems. This review gives an overview of the breakthrough in the application of biofilm platforms for the sustainable production of valuable compounds, with particular insight into the latest advances in the production of recombinant proteins. Productive biofilms are shown to improve production rates and product yields, demonstrating great potential for industrial applications. In recent years, abundant research has been performed on biofilms for the production of compounds with biotechnological and industrial relevance. The use of biofilm platforms has been seen as a compelling approach to producing fine and bulk chemicals such as organic acids, alcohols, and solvents. However, the production of recombinant proteins using this system is still scarce. Biofilm reactors are known to have higher biomass density, operational stability, and potential for long-term operation than suspended cell reactors. In addition, there is an increasing demand to harness industrial and agricultural wastes and biorefinery residues to improve process sustainability and reduce production costs. The synthesis of recombinant proteins and other high-value compounds is mainly achieved using suspended cultures of bacteria, yeasts, and fungi. This review discusses the use of biofilm reactors for the production of recombinant proteins and other added-value compounds using bacteria and fungi