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Emission from quantum-dot high-β microcavities: transition from spontaneous emission to lasing and the effects of superradiant emitter coupling

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Light(Science & Applications) 2017年第1期6卷 638-645页

作者： Sören Kreinberg Weng W Chow Janik Wolters Christian Schneider Christopher Gies Frank Jahnke Sven Höfling martin kamp Stephan Reitzenstein 无 Institut für Festkörperphysik Technische Universität BerlinBerlin 10623Germany Sandia National Laboratories AlbuquerqueNM 87185-1086USA Lehrstuhl für Technische Physik Universität WürzburgWürzburg 97074Germany School of Physics and Astronomy University of St AndrewsSt Andrews KY169SSUK Institute for Theoretical Physics University of BremenBremen 28334Germany

Measured and calculated results are presented for the emission properties of a new class of emitters operating in the cavity quantum electrodynamics *** structures are based on high-finesse GaAs/AlAs micropillar cavities,each with an active medium consisting of a layer of InGaAs quantum dots(QDs)and the distinguishing feature of having a substantial fraction of spontaneous emission channeled into one cavity mode(highβ-factor).This paper demonstrates that the usual criterion for lasing with a conventional(lowβ-factor)cavity,that is,a sharp non-linearity in the input–output curve accompanied by noticeable linewidth narrowing,has to be reinforced by the equal-time second-order photon autocorrelation function to confirm *** paper also shows that the equal-time second-order photon autocorrelation function is useful for recognizing superradiance,a manifestation of the correlations possible in high-βmicrocavities operating with *** terms of consolidating the collected data and identifying the physics underlying laser action,both theory and experiment suggest a sole dependence on intracavity photon *** for this assertion comes from all our measured and calculated data on emission coherence and fluctuation,for devices ranging from light-emitting diodes(LEDs)and cavity-enhanced LEDs to lasers,lying on the same two curves:one for linewidth narrowing versus intracavity photon number and the other for g(2)(0)versus intracavity photon number.

关键词： coherence laser physics microlasers nanolasers optoelectronics photon statistics quantum dots quantum optics

Sharpening emitter localization in front of a tuned mirror

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Light(Science & Applications) 2018年第1期7卷 71-78页

作者： Hannah S.Heil Benjamin Schreiber Ralph Götz Monika Emmerling Marie-Christine Dabauvalle Georg Krohne Sven Höfling martin kamp Markus Sauer Katrin G.Heinze Rudolf Virchow Center Research Center for Experimental BiomedicineUniversity of WürzburgJosef-Schneider-Str.297080 WürzburgGermany Department of Biotechnology and Biophysics BiozentrumUniversity of WürzburgAm Hubland97074 WürzburgGermany Technische Physik Physikalisches Institut and Wilhelm Conrad Röntgen-Center for Complex Material SystemsUniversity of WürzburgAm Hubland97074 WürzburgGermany Division of Electron Microscopy BiozentrumUniversity of WürzburgAm Hubland97074 WürzburgGermany SUPA School of Physics and AstronomyUniversity of St AndrewsSt Andrews KY169SSUK

Single-molecule localization microscopy(SMLM)aims for maximized precision and a high signal-to-noise *** features can be provided by placing the emitter in front of a metal-dielectric nanocoating that acts as a tuned mirror2–***,we demonstrate that a higher photon yield at a lower background on biocompatible metal-dielectric nanocoatings substantially improves SMLM performance and increases the localization precision by up to a factor of *** resolution improvement relies solely on easy-to-fabricate nanocoatings on standard glass coverslips and is spectrally and spatially tunable by the layer design and wavelength,as experimentally demonstrated for dual-color SMLM in cells.

关键词： emitter mirror tunable

Glacier Fluctuations between 1975 and 2008 in the Greater Himalaya Range of Zanskar,Southern Ladakh

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Journal of Mountain Science 2011年第3期8卷 374-389页

作者： Ulrich kamp martin BYRNE Tobias BOLCH Department of Geography The University of Montana Geographisches Institut Universitt Zürich

Glaciers in the Himalaya are often heavily covered with supraglacial debris,making them difficult to study with remotely-sensed imagery *** methods such as band ratios can be used effectively to map clean-ice glaciers;however,a thicker layer of debris often makes it impossible to distinguish between supraglacial debris and the surrounding ***,a morphometric mapping approach employing an ASTER-derived digital elevation model has been used to map glaciers in the Khumbu Himal and the Tien *** study on glaciers in the Greater Himalaya Range in Zanskar,southern Ladakh,aims (i) to use the morphometric approach to map large debris-covered glaciers;and (ii) to use Landsat and ASTER data and GPS and field measurements to document glacier change over the past four *** work was carried out in the summers of *** clean ice,band ratios from the ASTER dataset were used to distinguish glacial *** debris-covered glaciers,topographic features such as slope were combined with thermal imagery and supervised classifiers to map glacial *** method is promising for large glaciers,although problems occurred in the distal and lateral parts and in the fore field of the glaciers.A multi-temporal analysis of glaciers in Zanskar showed that in general they have receded since at least the mid-to ***,some few glaciers that advanced or oscillated - probably because of specific local environmental conditions - do exist.

关键词： Glacier Mapping Himalaya Ladakh Monitoring Zanskar

Laser-generated high entropy metallic glass nanoparticles as bifunctional electrocatalysts

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Nano Research 2022年第6期15卷 4807-4819页

作者： Jacob Johny Yao Li Marius kamp Oleg Prymak Shun-Xing Liang Tobias Krekeler martin Ritter Lorenz Kienle Christoph Rehbock Stephan Barcikowski Sven Reichenberger Technical Chemistry I and Center for Nanointegration Duisburg-Essen(CENIDE) University of Duisburg-EssenEssen 45141Germany Institute for Materials Science Synthesis and Real StructureKiel UniversityKiel 24143Germany Inorganic Chemistry and Center for Nanointegration Duisburg-Essen(CENIDE) University of Duisburg-EssenEssen 45141Germany Electron Microscopy Unit Hamburg University of TechnologyHamburg 21073Germany

High entropy metallic glass nanoparticles(HEMG NPs)are very promising materials for energy conversion due to the wide tuning possibilities of electrochemical potentials offered by their multimetallic character combined with an amorphous *** until now,the generation of these HEMG NPs involved tedious synthesis procedures where the generated particles were only available on highly specialized supports,which limited their widespread ***,more flexible synthetic approaches to obtain colloidal HEMG NPs for applications in energy conversion and storage are highly *** utilized pulsed laser ablation of bulk high entropy alloy targets in acetonitrile to generate colloidal carbon-coated CrCoFeNiMn and CrCoFeNiMnMo HEMG *** in-depth analysis of the structure and elemental distribution of the obtained nanoparticles down to single-particle levels using advanced transmission electron microscopy(TEM),energy-dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),and Xray photoelectron spectroscopy(XPS)methods revealed amorphous quinary and senary alloy phases with slight manganese oxide/hydroxide surface segregation,which were stabilized within graphitic *** on the catalytic activity of the corresponding carbon-HEMG NPs during oxygen evolution and oxygen reduction reactions revealed an elevated activity upon the incorporation of moderate amounts of Mo into the amorphous alloy,probably due to the defect generation by atomic size ***,we demonstrate the superiority of these carbon-HEMG NPs over their crystalline analogies and highlight the suitability of these amorphous multi-elemental NPs in electrocatalytic energy conversion.

关键词： high entropy alloy pulsed laser ablation in liquid amorphous catalysis oxygen evolution reaction oxygen reduction reaction

青藏高原东缘中生代若尔盖古高原的发现及其地质意义

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成都理工大学学报（自然科学版） 2019年第1期46卷 1-28页

作者：刘树根李智武 Peter J.J.kamp 冉波李金玺邓宾王国芝 Ganqing XU martin Daniík 杨迪王自剑李祥辉刘顺李巨初油气藏地质及开发工程国家重点实验室(成都理工大学) 成都610059 School of Science University of Waikato School of ScienceUniversity of Waikato Johnde Laeter Centre The Institute for Geoscience ResearchDepartment of Applied Geology and Applied PhysicsCurtin University 南京大学地球科学与工程学院南京210046

40 Ma B.P."原青藏高原"的提出使得青藏高原的早期隆升历史受到越来越多的关注,但其向东的延伸情况不明。青藏高原东缘若尔盖高原、龙门山冲断带和四川盆地有机地构建了一个完整的原-山-盆体系,成为揭示青藏高原隆升和生长的理想场所,... 详细信息

40 Ma B.P."原青藏高原"的提出使得青藏高原的早期隆升历史受到越来越多的关注,但其向东的延伸情况不明。青藏高原东缘若尔盖高原、龙门山冲断带和四川盆地有机地构建了一个完整的原-山-盆体系,成为揭示青藏高原隆升和生长的理想场所,而位于高原内部若尔盖地块的红参1井更为此提供了宝贵素材。基于红参1井的构造恢复和低温热年代学研究结果,结合区域上已有的低温热年代学和古高程数据,提出青藏高原东缘在早新生代印-亚大陆碰撞之前就已形成了高原,称之为若尔盖古高原,并从基底构造属性、构造变形、地壳缩短与增厚、沉积记录等方面对其进行了论证。红参1井钻井剖面构造恢复结果揭示所钻遇7 000余米的三叠系复理石层系实际上有46%的厚度是由构造重复所致,连同广泛发育的晚三叠世埃达克质花岗岩以及利用中性岩浆岩Sr/Y比值估算的地壳厚度,共同表明青藏高原东部松潘-甘孜地区在晚三叠世就已发生了实质性的地壳加厚。红参1井多重低温热年代学[锆石(U-Th)/He,磷灰石裂变径迹和(U-Th)/He]测试结果揭示若尔盖地块分别在白垩纪中期(约120 Ma B.P.和约80 Ma B.P.)经历了2次快速的冷却事件,累计剥蚀厚度达5 km,之后转入极其缓慢的冷却过程,暗示其已进入高原化阶段;而在整个新生代期间处于近乎"零"剥蚀的状态而被动地抬升到现今高度(不同于常见的山脉隆升,地块隆升代表了一定范围的区域整体抬升)。因此,青藏高原东部若尔盖地块最晚在白垩纪末期就已形成高原,即若尔盖古高原,其范围可能包括三叠系复理石层系覆盖的大部分松潘-甘孜地区,并可能向西与羌塘古高原相连,构成羌塘-若尔盖古高原。若尔盖古高原的形成不仅造成四川盆地西缘在白垩纪中期出现了重要的物源转变,更重要的是加剧了青藏高原东缘白垩纪气候干旱化,出现了大量沙漠沉积和膏盐沉积。若尔盖古高原的发现不仅有助于深化对青藏高原隆升和生长过程的理解,也将引发对青藏高原形成机制的重新思考以及对其气候-环境-资源效应的关注。

关键词：构造变形隆升剥蚀沉积记录地壳加厚中生代古高原若尔盖地块青藏高原