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Excitation and relaxation dynamics in ultrafast laser irradiated optical glasses

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High Power Laser Science and Engineering 2016年第4期4卷 1-8页

作者： C.Mauclair A.Mermillod-Blondin K.Mishchik J.Bonse A.Rosenfeld J.P.Colombier R.Stoian laboratoire hubert curien UMR 5516 CNRSUniversité de LyonUniversité Jean Monnet Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie Bundesanstalt für Materialforschung und-prüfung (BAM)

We discuss the dynamics of ultrashort pulsed laser excitation in bulk optical silica-based glasses(fused silica and borosilicate BK7) well-above the permanent modification threshold. We indicate subsequent structural and thermomechanical energy relaxation paths that translate into positive and negative refractive index changes, compression and rarefaction zones. If fast electronic decay occurs at low excitation levels in fused silica via self-trapping of excitons,for carrier densities in the vicinity of the critical value at the incident wavelength, persistent long-living absorptive states indicate the achievement of low viscosity matter states manifesting pressure relaxation, rarefaction, void opening and compaction in the neighboring domains. An intermediate ps-long excited carrier dynamics is observed for BK7 in the range corresponding to structural expansion and rarefaction. The amount of excitation and the strength of the subsequent hydrodynamic evolution is critically dependent on the pulse time envelope, indicative of potential optimization schemes.

关键词： carrier plasmas glasses pulse shaping refractive index engineering ultrafast laser excitation

Saliency-based framework for facial expression recognition

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Frontiers of Computer Science 2019年第1期13卷 183-198页

作者： Rizwan Ahmed KHAN Alexandre MEYER hubert KONIK Saida BOUAKAZ Universite de Lyon CNRSLIRISUMR5205Universite Lyon 1Lyon F-69622France Faculty of Information Technology Barrett Hodgson UniversityKarachi 74900Pakistan laboratoire hubert curien UMR5516Universite Jean MonnetSaint-Etienne 42000France

This article proposes a novel framework for the recognition of six universal facial *** framework is based on three sets of features extracted from a face image:entropy,brightness,and local binary ***, saliency maps are obtained using the state-of-the-art saliency detection algorithm "frequency-tuned salient region detection".The idea is to use saliency maps to determine appropriate weights or values for the extracted features (i.e.,brightness and entropy).We have performed a visual experiment to validate the performance of the saliency detection algorithm against the human visual *** movements of 15 subjects were recorded using an eye-tracker in free-viewing conditions while they watched a collection of 54 videos selected from the Cohn-Kanade facial expression *** results of the visual experiment demonstrated that the obtained saliency maps are consistent with the data on human ***,the performance of the proposed framework is demonstrated via satisfactory classification results achieved with the Cohn-Kanade database,FG-NET FEED database, and Dartmouth database of children's faces.

关键词： facial expression recognition classification salient regions entropy brightness local binary pattern

Supporting flexible regulation of crisis management by means of situated artificial institution

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Frontiers of Information Technology & Electronic Engineering 2016年第4期17卷 309-324页

作者： Maiquel DE BRITO Lauren THEVIN Catherine GARBAY Olivier BOISSIER Jomi Fred HUBNER Federal University of Santa Catarina UFSC/CTC/DAS/PPGEAS-PO Box 476FlorianopolisSC 88040-900Brazil LIG/Universite de Grenoble Grenoble 38041France laboratoire hubert curien umr cnrs 5516 Institut Henri FayolMINES Saint-EtienneSaint-Etienne 42023France

This paper highlights the use of situated artificial institution(SAI) within a hybrid, interactive,normative multi-agent system to regulate human collaboration in crisis management. Norms regulate the actions of human actors based on the dynamics of the environment in which they are situated. This dynamics results from both environment evolution and actors' actions. Our objective is to situate norms in the environment in order to provide a context-aware crisis regulation. However, this coupling must be a loose one to keep both levels independent and easyto-change in order to face the complex and changing crisis situations. To that aim, we introduce a constitutive level between environmental and normative states providing a loose coupling of normative regulation with environment evolution. Norms are thus no more referring to environmental facts but to status functions, i.e., the institutional interpretation of environmental facts through constitutive rules. We present how this declarative and distinct SAI modelling succeeds in managing the crisis with a context-aware crisis regulation.

关键词： Situated artificial institutions(SAIs) Normative system Tangible interaction Crisis management

Ultrashort Bessel beam photoinscription of Bragg grating waveguides and their application as temperature sensors

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Photonics Research 2019年第7期7卷 121-129页

作者： Guodong Zhang Guanghua Cheng Manoj K.Bhuyan Ciro D'Amico Yishan Wang Razvan Stoian laboratoire hubert curien UMR 5516 CNRSUniversite de LyonUniversite Jean Monnet42000 Saint EtienneFrance State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision MechanicsCASXi'an 710119China School of Electronics and Information Northwestern Polytechnical UniversityXi'an 710072China Academy of Scientific and Innovative Research CSIR-Central Scientific Instruments OrganizationChandigarh 160030India Optical Devices and Systems Division CSIR-Central Scientific Instruments OrganizationChandigarh 160030India

Ultrashort pulsed Bessel beams with intrinsic nondiffractive character and potential strong excitation confinement down to 100nm can show a series of advantages over Gaussian beams in fabricating efficient Bragg grating waveguides(BGWs).In this work, we focus on parameter management for the inscription of efficient BGWs using the point-by-point method employing Bessel *** to their high aspect ratio, the resulting one-dimensional void-like structures can section the waveguides and interact efficiently with the optical modes. Effective first-order BGWs with low birefringence can then be fabricated in bulk fused silica. By controlling the size and the relative location of grating voids via the Bessel pulse energy and scan velocities, the resonant behaviors of BGWs can be well regulated.A high value of 34 dB for 8 mm length is achieved.A simple predictive model for BGWs is proposed for analyzing the influences of processing parameters on the performance of BGWs. The technique permits multiplexing several gratings in the same *** to eight grating traces were straightforwarcliy inscribed into the waveguide in a parallel-serial combined mode, forming the multiplex *** an application, the multiplex BGW sensor with two resonant peaks is proposed and fabricated for improving the reliability of temperature detection.

关键词： photoinscription waveguides temperature detection

飞秒激光诱导金属钨表面周期性自组织结构的研究

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光学学报 2016年第5期36卷 312-318页

作者：李晨程光华 Stoian Razvan 中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室陕西西安710119 中国科学院大学北京100049 laboratoire hubert curien UMR 5516 CNRSUniversite de LyonUniversite Jean MonnetSaint Etienne France 42000

飞秒激光诱导金属表面周期性自组织微纳米条纹结构,在调控热辐射源、摩擦、超亲水性、超疏水性和打标等方面具有广泛的应用前景.研究了800nm飞秒激光诱导金属钨表面周期性自组织结构的形成规律和形成机理.采用Sipe干涉模型和有限时域差... 详细信息

飞秒激光诱导金属表面周期性自组织微纳米条纹结构,在调控热辐射源、摩擦、超亲水性、超疏水性和打标等方面具有广泛的应用前景.研究了800nm飞秒激光诱导金属钨表面周期性自组织结构的形成规律和形成机理.采用Sipe干涉模型和有限时域差分法,仿真了第1个飞秒激光脉冲刻蚀后随机粗糙表面引起的激光电磁场能量表面分布和第20个脉冲后低空间频率条纹结构引起的激光电磁场能量表面分布.揭示了低空间频率条纹与高空间频率条纹的形成机理,考察了表面微观形貌的演化和条纹周期随着脉冲增多而递减的现象.

关键词：超快光学飞秒激光微加工钨有限时域差分法

Turbulence and suspended sediment processes in the Garonne River tidal bore in November 2016

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International Journal of Sediment Research 2019年第5期34卷 496-508页

作者： David Reungoat Xinqian Leng hubert Chanson Université de Bordeaux I2MLaboratoire TREFLE cnrs umr 5295 The University of Queensland School of Civil Engineering

A tidal bore is a water discontinuity at the leading edge of a flood tide wave in estuaries with a large tidal range and funneling topography. New measurements were done in the Garonne River tidal bore on14–15 November 2016, at a site previously investigated between 2010 and 2015. The data focused on long, continuous, high-frequency records of instantaneous velocity and suspended sediment concentration(SSC) estimate for several hours during the late ebb, tidal bore passage and flood tide. The bore passage drastically modified the flow field, with very intense turbulent and sediment mixing. This was evidenced with large and rapid fluctuations of both velocity and Reynolds stress, as well as large SSCs during the flood tide. Granulometry data indicated larger grain sizes of suspended sediment in water samples compared to sediment bed material, with a broader distribution, shortly after the tidal bore. The tidal bore induced a sudden suspended sediment flux reversal and a large increase in suspended sediment flux magnitude. The time-variations of turbulent velocity and suspended sediment properties indicated large fluctuations throughout the entire data set. The ratio of integral time scales of SSC to velocity in the x-direction was on average TE,SSC/TE,～0.16 during the late ebb tide, compared to TE,SSC/TE,～0.09 during the late flood tide. The results imply different time scales between turbulent velocities and suspended sediment concentrations.

关键词： Tidal bore Garonne River Hydrodynamics Suspended sediment Field observations Turbulence-sediment suspension interactions

S1P: the elixir of life for naive T cells

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Cellular & Molecular Immunology 2018年第7期15卷 657-659页

作者： Michaël Pérès Anne Montfort Nathalie Andrieu-Abadie Céline Colacios Bruno Ségui INSERM umr1037 Centre de Recherches en Cancérologie de ToulouseToulouse 31037France Facultéde pharmacie UniversitéToulouse III Paul-SabatierToulouse 31062France laboratoire d’hématologie CHU de ToulouseToulouse 31059France Equipe Labellisée Ligue Contre Le Cancer Toulouse 31037France Correspondence:Professor B SéguiPhDINSERMUMR1037 CRCTCentre de Recherches en Cancérologie de Toulouse2 avenue Hubert CurienToulouse 31037France

During their life,T cells are constantly circulating throughout the ***-1-phosphate(S1P),a sphingolipid metabolite,triggers T cell egress from the thymus and secondary lymphoid organs(SLO)into the lymph and the *** phenomenon is dependent on the S1P gradient between lymphoid organs(including thymus and SLO)and the lymphatic and blood vessels,which exhibit low,intermediate and high S1P levels,respectively.T cells follow the S1P gradient via the engagement of the G-protein-coupled receptor S1P receptor 1(S1P1)expressed on T cells.1 S1P production is regulated by various sphingolipid-metabolizing *** sphingosine kinases 1 and 2(SKs),encoded by Sphk1 and Sphk2,phosphorylate the sphingosine(Sph)into ***,S1P can be dephosphorylated to Sph by S1P phosphatases 1 and 2,encoded by Sgpp1 and ***,S1P can be irreversibly degraded by the S1P Lyase(SPL),encoded by Sgpl1,into phosphoethanolamine and hexadecenal.

关键词： organs al. lymphoid

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飞秒激光光刻波导偏振器

光子学报 2011年第6期40卷 818-822页

作者：林灵杨小君白晶龙学文吕百达 Razvan Stoian 惠荣庆程光华四川大学激光物理与化学研究所成都610064 中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室西安710119 laboratoire hubert curien UMR5516 CNRS Universit'e de Lyon Universit'e Jean Monnet Depart ment of Electrical Engineering and Computer Science The University of Kansas

飞秒激光诱导折射率变化提供了一种灵活的三维光子器件制作手段.飞秒激光光刻的II类波导具有偏振导光特性,可以作为波导偏振器,但是对于要保留的偏振分量损耗太大.本文阐述了一种利用飞秒激光在熔融石英中制作的新型低损耗波导偏振器.... 详细信息

飞秒激光诱导折射率变化提供了一种灵活的三维光子器件制作手段.飞秒激光光刻的II类波导具有偏振导光特性,可以作为波导偏振器,但是对于要保留的偏振分量损耗太大.本文阐述了一种利用飞秒激光在熔融石英中制作的新型低损耗波导偏振器.它由中间的一根I类波导及两侧的两根II类纳米光栅轨迹构成.基于飞秒激光诱导的纳米光栅的偏振依赖散射特性,II类纳米光栅轨迹能够对I类波导的倏逝场进行调制.偏振方向垂直于纳米光栅的模式相对于偏振方向平行于纳米光栅的模式有更大的散射损耗,因此导通的是偏振方向平行于纳米光栅的模式.研究了消光比随I类波导与II类纳米光栅轨迹之间的间距的变化关系,选择一个最佳间距来进一步研究消光比随II类纳米光栅轨迹长度的变化关系.在间距6μm,II类纳米光栅轨迹扫描长度6 mm处实现了最大15.91 dB的消光比.通过增加II类轨迹的长度或者数量,很容易得到更高的消光比.

关键词：飞秒激光光刻波导偏振器

Design of a Multimodal Light Sheet Optical System for Multivariate Applications in Phytopathology

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Optics and Photonics Journal 2021年第5期11卷 110-120页

作者： Mama Sangare Mathieu Hebert Anthony Cazier Pierre Chavel Institut des Sciences Appliquées Université des Sciences Techniques et Technologies de Bamako (USTTB) Bamako Mali laboratoire hubert curien Institut d’Optique Graduate School Université Jean Monnet de Saint-Etienne Université de Lyon CNRS Saint-Etienne France

The design of optical instruments is an active subject due to improvement in lens techniques, fabrication technology, and data handling capacity. Much remains to do to expand its application to phytopathology, which would be in particular quite useful to improve crop growth monitoring in countries like Mali. An optical multimodal system for plant samples has been developed to improve the characterization of leaf disease symptoms, provide information on their effects, and avoid their spread. Potentially inexpensive components (laser, lens, turntables camera and sample, filter, lens, camera and computer) have been selected, assembled and aligned on an optical table into a multimodal system operating in transmission, reflection, diffusion and fluorescence. The illumination and observation angles can be adjusted to optimize viewing conditions in the four modes. This scientific contribution has been an initiation into the design and implementation of an optical instrument. Initial results are shown and will now be extended in cooperation with agronomic laboratories in African countries for tests on specific plant diseases in relation with prevailing climate conditions.

关键词： Design Optical System Light Sheet Multimodal Multivariate Phytopathology