Complex photonic nonlinear delay dynamics for high performance signal and information processing

International audienceOptoelectronic delayed feedback loops can provide a wide variety of dynamical motions, thanks to their infinite dimensional phase space. When implemented with Telecom grade components, they additionally provide broadband operation, particularly suited for high speed signal and information processing. On the basis on experimental illustration, we will introduce the fundamental nonlinear dynamical properties of photonic delayed feedback systems, from their stable fixed point operation to their high dimensional complex chaotic oscillations, through periodic oscillations. Each of these particular solution will then be further developed to demonstrate advanced information and signal processing capabilities, from secure optical chaos communications at 10Gb/s, to ultra-fast million word per second recognition through neuromorphic computing, through microwave high spectral purity oscillations for radar applications

Cover crops (living mulches) in the tree row of organic orchards: why and how? (BIOFRUITNET Practice Abstract)

After establishing living mulch, tree row maintenance is cheaper and, depending on the species, can provide different ecosystem services (e.g., nitrogen fixation), functional biodiversity (e.g., nectar source for pollinators, habitat for beneficials), soil conservation, etc... The cultivation of secondary cash crops as living mulch can be a source of additional income. Practical recommendation • Prepare the establishment of the living mulch with summer tillage, then prepare the seedbed in early autumn. • Prefer short, low-lying perennial species with high capacity of soil coverage in irrigated orchards. • For perennial species, sow or plant living mulches in autumn to favour their establishment. During the first season, one or two mowings and possibly manual weed control may be necessary. After establishment, if necessary, mow once a year to maintain a moderate plant height. • Among the perennial living mulching species adapted to orchards in different pedo-climatic conditions: yarrow (Achillea millefolium, Picture 1), wild strawberries (Fragaria vesca), peppermint (Mentha piperita), lady’s mantle (Alchemilla vulgaris, Picture 2), crawling thymes (Thymus spp.), mouse-ear hawkweed (Pilosella officinarum), caucasian crosswort (Phuopsis stylosa, Picture 3), creeping cinquefoil (Potentilla reptans) and white bedstraw (Galium album). • For rainfed orchards or those with a high risk of vole damage, favour the sandwich system (Tschabold, 2009) or the cultivation of annual species (vegetables, annual clover, etc.). • When selecting the species, favour local ecotypes better adapted to pedo-climatic conditions

Applications of femtosecond Bessel beams to laser ablation

International audienceNondiffracting Bessel beams have been recently applied to single shot ultrafast laser processing of high aspect ratio nanochannels.We review the principles and benefits of nondiffracting Bessel beams for material processing, and we compare experimental results with numerical simulations. We show how the stationarity of nonlinear propagation of ultrafast laser pulses allows high aspect ratio material processing