Dissertations / Theses on the topic 'Ultrafast microscopy'
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Li, Jing. "Ultrafast thermoreflectance microscopy." Thesis, Boston University, 2013. https://hdl.handle.net/2144/11118.
Full textAs electronic and photonic devices shrink to the nanoscale, heat dissipation becomes the bottleneck for performance. As a result, understanding and controlling nanoscale thermal transport in thin films and across interfaces is a critical issue requiring new experimental tools. In this thesis, the development of an ultrafast thermoreflectance microscope for high resolution thermal property imaging is described. It can function as a time domain thermoreflectance (TDTR) or frequency domain thermoreflectance (FDTR) system. Design and implementation of the optical system will be introduced in detail. A thermal model derived from heat transfer theory is used to analyze the experimental data and obtain quantitative property maps for bulk and thin-film samples. The system is used to obtain temperature dependent thermal properties of single crystal diamond and thin film VO2, as well as thermal property maps of several thin film samples.
Block, Alexander. "Quantifying nanoscale carrier diffusion with ultrafast optical and photocurrent microscopy." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/668392.
Full textEl transporte de calor en sólidos es uno de los problemas más antiguos de la física, que se remonta a las primeras formulaciones de la termodinámica. Las leyes clásicas de la conducción de calor son válidas cuando las escalas de tiempo y longitud observadas sean mayores que el tiempo de relajación y la trayectoria libre media de los portadores de calor microscópicos subyacentes, como los electrones y los fonones. Con la llegada de los láseres ultrarrápidos y los sistemas a nanoescala, estos regímenes ahora pueden superarse por lo cual se necesitan nuevos modelos refinados de transporte de calor. En particular, la interacción de pulsos de luz ultracortos con la materia puede excitar electrones a altas temperaturas, lo que lleva a un desequilibrio local de electrones y fonones. En estas condiciones, también se modifican las propiedades de transporte de los portadores de calor. Hasta ahora, estos efectos han sido típicamente estudiados en el dominio del tiempo. El enfriamiento de electrones calientes fotoexcitados se ha estudiado tanto en metales como en nuevos materiales bidimensionales, como el grafeno. Sin embargo, debido a la falta de resolución espacio-temporal, no ha sido posible distinguir los efectos de la difusión de electrones calientes de otros mecanismos de enfriamiento, como el acoplamiento de electrones y fonones. En esta tesis, hago un seguimiento directo de la difusión del calor y sus portadores en el espacio y el tiempo con microscopía ultrarrápida. Al utilizar la técnica recientemente desarrollada de microscopía de absorción transitoria con escaneo de sonda en películas de oro delgadas, resuelvo directamente, por primera vez, una transición de la difusión de electrones calientes a la difusión limitada por fonones en la escala de tiempo de picosegundos. Apoyo la comprensión de estas dinámicas complejas mediante el modelado teórico de la respuesta termo-óptica basada en un modelo de dos temperaturas. Aplico la misma técnica para estudiar la difusión de portadores calientes en una capa de grafeno atómicamente delgado. Al comparar muestras preparadas de manera diferente, estudio la fuerte influencia de los parámetros externos, como el tipo de producción, el sustrato y el entorno sobre la difusión del portador. Finalmente, estudio la difusión de portadores en dispositivos de grafeno exfoliados y encapsulados con una técnica novedosa de microscopía de fotocorriente espacio-temporal ultrarrápida basada en el efecto fototermoeléctrico. Extraigo dinámicas de difusión para muestras caracterizadas eléctricamente con la ayuda del modelado espacio-temporal teórico, probando así la relación fundamental entre el transporte eléctrico y térmico. La cuantificación precisa del transporte de los portadores ultrarrápido y a nanoescala con estas técnicas de vanguardia lleva a una comprensión más amplia de la dinámica del no equilibrio y podría, en última instancia, ayudar al diseño, la optimización y la gestión del calor de la próxima generación de dispositivos (opto-)electrónicos ultracompactos, como células solares, fotodetectores o circuitos integrados.
Wong, Tsz-wai Terence, and 黃子維. "Optical time-stretch microscopy: a new tool for ultrafast and high-throughput cell imaging." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B5066234X.
Full textpublished_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy
Bücker, Kerstin. "Characterization of pico- and nanosecond electron pulses in ultrafast transmission electron microscopy." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE014/document.
Full textThis thesis presents a study of ultrashort electron pulses by using the new ultrafast transmission electron microscope (UTEM) in Strasbourg. The first part focuses on the stroboscopic operation mode which works with trains of picosecond multi-electron pulses in order to study ultrafast, reversible processes. A detailed parametric study was carried out, revealing fundamental principles of electron pulse dynamics. New mechanisms were unveiled which define the pulse characteristics. These are trajectory effects, limiting the temporal resolution, and chromatic filtering, which acts on the energy distribution and signal intensity. Guidelines can be given for optimum operation conditions adapted to different experimental requirements. The second part starts with the setup of the single-shot operation mode, based on intense nanosecond electron pulses for the investigation of irreversible processes. Having the first ns-UTEM equipped with an electron energy loss spectrometer, the influence of chromatic aberration was studied and found to be a major limitation in imaging. It has to be traded off with spherical aberration and signal intensity. For the first time, the feasibility of core-loss EELS with one unique ns-electron pulse is demonstrated. This opens a new field of time-resolved experiments
Danz, Thomas Christian [Verfasser]. "Ultrafast transmission electron microscopy of a structural phase transition / Thomas Christian Danz." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1239061234/34.
Full textGe, Xiaowei. "Nonlinear Microscopy Based on Femtosecond Fiber Laser." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1556914609069399.
Full textBarlow, Aaron M. "Spectral Distortions & Enhancements In Coherent Anti-Stokes Raman Scattering Hyperspectroscopy." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32388.
Full textGanz, Thomas. "Supercontinuum generation by chirped pulse compression for ultrafast spectroscopy and broadband near-field microscopy." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-148551.
Full textCiesielski, Richard [Verfasser], and Achim [Akademischer Betreuer] Hartschuh. "Ultrafast dynamics in single nanostructures investigated by pulse shaping microscopy / Richard Ciesielski. Betreuer: Achim Hartschuh." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2016. http://d-nb.info/1111505330/34.
Full textChung, Hsiang-Yu [Verfasser], and Franz X. [Akademischer Betreuer] Kärtner. "Advanced fiber-optic ultrafast laser sources for multiphoton microscopy / Hsiang-Yu Chung ; Betreuer: Franz X. Kärtner." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://d-nb.info/1213901227/34.
Full textKeunecke, Marius [Verfasser]. "Ultrafast electron dynamics measured with a novel time-resolved high-repetition rate momentum microscopy setup / Marius Keunecke." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1230628428/34.
Full textCaruso, Giuseppe Mario. "Development of a coherent ultrafast transmission electron microscope based on a laser-driven cold field emission source." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30140.
Full textThe investigation of the physics of nanoscale systems ideally requires atomic spatial resolution and femtosecond time-resolution. Ultrafast Transmission Electron Microscopy (UTEM) combining subpicosecond temporal resolution and nanometer spatial resolution has recently emerged as a unique tool with unprecedented spatio-temporal resolutions. However, the performances of the first UTEMs were limited by the brightness of the photocathodes used as ultrafast electron source. In this context, it was soon realized that UTEMs relying on laser-driven electron sources based on nanoscale emitters would overcome this limitation. The aim of this thesis is to report the development of an ultrafast Transmission Electron Microscope based on a cold field emission source, which can operate either in DC or ultrafast mode. Electron emission from a tungsten nanotip is triggered by femtosecond laser pulses, which are tightly focused by optical components integrated inside a cold-field emission source close to the cathode. The measured brightness is the largest reported so far for UTEMs. Combining this new high brightness source with an injection/Cathodoluminescence system, composed of a parabolic mirror placed above the sample holder, the UTEM can be used to perform time-resolved ultrafast pump-probe TEM experiments. The possibilities of such an instrument for ultrafast imaging, diffraction, electron holography and spectroscopy are presented. Particular attention has been paid on applications in nano-optics. In particular, Electron Energy Gain Spectroscopy (EEGS) allows to investigate the optical excitations of nanosystems in the energy domain. The ability to easily synchronize ultrashort free electron pulses with the optical excitation of the sample in UTEMs is essential for the observation of strongly nonlinear electron/photon interactions. These experiments will enable us to characterize the spectro-temporal properties of the ultrashort electron beam. Off-axis electron holography performed with ultrafast electron pulses are finally discussed. The electron dose in the specimen plane is considerably reduced due to the low repetition rate of the electron pulse train. This peculiar property of ultrafast FE-TEMs implies that ultrafast holograms are acquired in low-dose-like conditions. As a consequence, the experimental parameters commonly used for the acquisition of off-axis electron holograms with conventional TEMs cannot be directly implemented in the ultrafast mode. Experimental studies were performed to find the optimum conditions for ultrafast off-axis electron holography. Influence of the dose, the coherence length of the source, the illumination condition and the instrument instabilities have been addressed
Khalil, Lama. "Ultrafast study of Dirac fermions in topological insulators." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS344/document.
Full textThis thesis presents an experimental study of the electronic properties of two topological materials, namely, the irradiated three-dimensional topological insulator Bi₂Te₃ and the natural topological superlattice phase Sb₂Te. Both systems were investigated by techniques based on photoemission spectroscopy. The Bi₂Te₃ compounds have been irradiated by high-energy electron beams. Irradiation with electron beams is a very promising approach to realize materials that are really insulating in the bulk, in order to emphasize the quantum transport in the protected surface states. By studying a series of samples of Bi₂Te₃ using time- and angle-resolved photoemission spectroscopy (trARPES) we show that, while the topological properties of the Dirac surface states are preserved after electron irradiation, their ultrafast relaxation dynamics are very sensitive to the related modifications of the bulk properties. Furthermore, we have studied the occupied and unoccupied electronic band structure of Sb₂Te. Using scanning photoemission microscopy (SPEM), we have consistently found various nonequivalent regions on the same surface after cleaving several Sb₂Te single crystals. We were able to identify three distinct terminations characterized by different Sb/Te surface stoichiometric ratios and with clear differences in their band structure. For the dominating Te-rich termination, we also provided a direct observation of the excited electronic states and of their relaxation dynamics by means of trARPES. Our results clearly indicate that the surface electronic structure is strongly affected by the bulk properties of the superlattice. Therefore, for both systems, we show that the surface electronic structure is absolutely connected to the bulk properties
Kolodziej, Charles. "Laser Spectroscopic Studies of Ultrafast Charge Transfer Processes in Solar Cell Materials." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1586371698913592.
Full textGanz, Thomas [Verfasser], and Ferenc [Akademischer Betreuer] Krausz. "Supercontinuum generation by chirped pulse compression for ultrafast spectroscopy and broadband near-field microscopy / Thomas Ganz. Betreuer: Ferenc Krausz." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2011. http://d-nb.info/102665355X/34.
Full textRubiano, da Silva Nara [Verfasser], Claus [Akademischer Betreuer] Ropers, Claus [Gutachter] Ropers, and Stefan [Gutachter] Mathias. "Ultrafast Lorentz Microscopy using High-Coherence Electron Pulses / Nara Rubiano da Silva ; Gutachter: Claus Ropers, Stefan Mathias ; Betreuer: Claus Ropers." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1185757678/34.
Full textBormann, Reiner [Verfasser], Claus [Akademischer Betreuer] Ropers, and Markus [Akademischer Betreuer] Münzenberg. "Development and characterization of an electron gun for ultrafast electron microscopy / Reiner Bormann. Betreuer: Claus Ropers. Gutachter: Claus Ropers ; Markus Münzenberg." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1080609954/34.
Full textBormann, Reiner Verfasser], Claus [Akademischer Betreuer] Ropers, and Markus [Akademischer Betreuer] [Münzenberg. "Development and characterization of an electron gun for ultrafast electron microscopy / Reiner Bormann. Betreuer: Claus Ropers. Gutachter: Claus Ropers ; Markus Münzenberg." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://nbn-resolving.de/urn:nbn:de:gbv:7-11858/00-1735-0000-0028-867D-4-8.
Full textYong, Chaw Keong. "Ultrafast carrier dynamics in organic-inorganic semiconductor nanostructures." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:b2efdc6a-1531-4d3f-8af1-e3094747434c.
Full textMitchell, Claire A. "Photoporation and optical manipulation of plant and mammalian cells." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/6328.
Full textFeist, Armin [Verfasser], Claus [Akademischer Betreuer] Ropers, Claus [Gutachter] Ropers, Tim [Gutachter] Salditt, and Klaus [Gutachter] Sokolowski-Tinten. "Next-Generation Ultrafast Transmission Electron Microscopy – Development and Applications / Armin Feist ; Gutachter: Claus Ropers, Tim Salditt, Klaus Sokolowski-Tinten ; Betreuer: Claus Ropers." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://d-nb.info/1165304872/34.
Full textPriebe, Katharina Elisabeth [Verfasser], Claus [Akademischer Betreuer] Ropers, Stefan [Gutachter] Mathias, and Thomas [Gutachter] Baumert. "Coherent Control and Reconstruction of Free-Electron Quantum States in Ultrafast Electron Microscopy / Katharina Elisabeth Priebe ; Gutachter: Stefan Mathias, Thomas Baumert ; Betreuer: Claus Ropers." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://d-nb.info/114995471X/34.
Full textBerberian, Delsalle Tiphaine. "Nouvelle source laser pour des applications en neuroscience." Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASP011.
Full textNeurosciences, whose ultimate goal is to cure neurodegenerative diseases, are undergoing major transformational advances. Among these is the development of efficient neural sensors allowing the detection of individual action potentials as well as the emergence of new optogenetic actuators. The existence of femtosecond laser sources, more or less energetic, in the 2-photon absorption spectral range of these molecules allows an all-optical investigation of neural networks in vivo and in 3D.The manuscript is part of a project involving different actors in the field of Research: the Laboratoire Charles Fabry for the laser aspect and the Institut de la Vision for the production of previously unseen biological images on subjects in vivo, as well as in the industrial field: Amplitude Systèmes, world leader in femtosecond fiber lasers, and ALPhANOV, a non-profit association which develops and integrates optical systems. The goal is to produce a tool allowing multicellular activation in 3D followed by a diagnostic allowing the analysis of the neuronal response at the millisecond scale. For this, I present the development of a specific laser (with pulses of sufficiently short and intense duration) allowing parallelized 2-photon excitation. In addition, this laser emits in the spectral range of the bio-activators and biosensors used, which makes it a completely original source.The development of this femtosecond laser based on thulium fiber is detailed. This laser has two outputs: a high speed output for imaging and a high energy output for photo-activation. This thesis includes an important experimental and technological part related to the design and analysis of pulsed laser sources. The performance demonstrated here for the high repetition rate channel is the emission of a power of 10 W around 1950 nm at a rate of 40 MHz. The high-energy channel developed, for its part, made it possible to demonstrate the generation of pulses of 10 µJ around 1950 nm. Once the frequency conversion has been carried out, the performance obtained is sufficiently promising to trigger initial tests on biological samples
Kim, Daekeun Ph D. Massachusetts Institute of Technology. "Ultrafast optical pulse manipulation in three dimensional-resolved microscope imaging and microfabrication." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/49759.
Full textIncludes bibliographical references.
The availability of lasers with femtosecond, ultrafast light pulses provides new opportunities and challenges in instrument design. This thesis addresses three aspects of utilizing ultrafast light pulses in two-photon excitation microscopy. First, optical fibers are routinely used in many optical instruments but their use in two-photon microscopy is very limited. As ultrafast light pulses propagate through conventional fiber optics, light pulses are dispersed and broadened, as a result of nonlinear interactions between light and material. Two-photon excitation efficiency is reduced with pulse broadening. The recent development of photonic crystal fibers allows unprecedented control of light properties through them. This thesis provides a thorough quantitative characterization of different conventional optical fibers and photonic crystal fibers enabling better utilization of these fibers for two-photon microscopic imaging. Second, two-photon microscopic imaging is relatively slow due to the sequential nature of raster scanning. Several groups have recently sought to overcome this limitation by developing a 3D-resolved wide-field two-photon microscope using the concept of temporal focusing that is based on manipulating the dispersion of ultrafast light pulses spatially. However, the existing temporal focusing systems have poor optical sectioning capability and, due to a shortage of illumination power, low actual frame rate. In this thesis, a comprehensive mathematical model is derived for temporal focusing two-photon microscope taking key instrument design parameters into account.
(cont.) By optimizing instrument design and the use of high two-photon cross section quantum dots, we demonstrate single quantum dot imaging at micron level resolution at video rate. Lastly, we realize that the temporal focus concept may also be used for microfabrication. A prototype three-dimensional lithographic microfabrication system is developed and micro patterning capability based on photobleaching process is demonstrated.
by Daekeun Kim.
Ph.D.
Mishchik, Konstantin. "Ultrafast laser-induced modification of optical glasses : a spectroscopy insight into the microscopic mechanisms." Phd thesis, Université Jean Monnet - Saint-Etienne, 2012. http://tel.archives-ouvertes.fr/tel-00966418.
Full textMatos, Raimundo Duarte de Joana Cristina. "Ultrafast Nanoscale 3D Coherent X-ray Imaging." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS372.
Full textCoherent lensless imaging techniques can break the limitations associated with conventional microscopy techniques. The configuration of coherent diffraction imaging makes it possible to image isolated non-crystalline objects with spatial resolutions limited, in principle, only by the illuminated wavelength (i.e. a few tens of nanometers to a few angstroms in the XUV and X domains, respectively). In this thesis, we develop and improve, experimentally and numerically, 2D and 3D lensless imaging techniques, for nanometric resolutions in a femtosecond single shot. Responding to the limitations of these techniques to aberrations and partial coherence, here, improvements of wavefront and spatial-coherence correction in holographic techniques are proposed. Indeed, the exploitation of the source properties makes possible to optimise the reconstruction from diffraction patterns or holograms in order to obtain the most faithful image possible in a single femtosecond flash. By exploiting machine vision concepts, this thesis also shows the possibility of accessing 3D information in single shots, extracted from two coherent X-ray diffraction patterns, taken simultaneously from two stereo angles. This opens the way towards the exploration of matter on nanometric volumes (voxels) solved at unmatched temporal resolutions
Mermillod-Blondin, Alexandre. "Analysis and optimization of ultrafast laser-induced bulk modifications in dielectric materials." Saint-Etienne, 2007. http://www.theses.fr/2007STET4004.
Full textEn focalisant une impulsion lumineuse ultra brève dans la masse d'un matériau diélectrique transparent, un mécanisme d'ionisation non-linéaire peut conduire à la création de porteurs libres. L'énergie lumineuse est alors efficacement déposée. Après relaxation de l'énergie, un matériau avec de nouvelles propriétés optiques est obtenu. Les propriétés optiques de ce matériau transformé ainsi que la morphologie de la zone altérée sont caractérisés en microscopie à contraste de phase et en microscopie optique classique. Les échantillons étudiés sont principalement la silice pure et le N-BK7. Les observations expérimentales sont corrélées avec une estimation théorique de la densité d'énergie déposée obtenue en résolvant l'équation de Schrödinger non-linéaire. Dans la silice pure, l'apparition d'une micro-cavité est ainsi associée à une région de forte exposition à l'énergie lumineuse. Une étude basée sur un dispositif de microscopie de phase et de microscopie classique caractérisée par une résolution spatiale submicrométrique et une résolution temporelle subpicoseconde est également présentée. Cette analyse révèle l'importance des phénomènes thermiques et des effets thermomécaniques. En optimisant la forme temporelle de l'impulsion, nous démontrons la possibilité de conduire le matériau de manière permanente dans des états inaccessibles lorsqu'on se limite à une irradiation ultra brève classique. En particulier, nous montrons l'existence de régions de densités élevées dans le BK7 après irradiation. Enfin, la souplesse offerte par la mise en forme temporelle est employée afin de réaliser l'écriture de guides d'ondes enterrés dans le BK7
Ayche, Kenza. "Propriétés mécaniques et structurales d'encapsulants polymères utilisés en microélectronique : effet de la température et de l'humidité." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1005/document.
Full textThe increasing number of mobile devices and the race to energy sobriety make the decrease of the size of microelectronic systems (MEMS) a major challenge. Today, Lithium micro batteries are currently the best solution for high-power-and-energy applications. Incorporate them into credit cards containing a screen or associate them to electronic sensors for the supervision is the challenge which raises international companies such as ST Microelectronics. However, these micro batteries contain some lithium metal which can be dangerous if the metallic lithium is in contact with water or humid air. In addition, the substance can spontaneously ignite in the contact of the humidity. So, in order to avoid the problems of safety, we absolutely have to protect the lithium contained in our micro batteries using an encapsulation layer. Polymeric encapsulation has the advantage, compared with other materials (ceramic, metal), to present a moderate cost of shaping and a low weight. However, such systems of encapsulation are today insufficient to guarantee a satisfactory life cycle of components. Indeed, in the presence of humidity or of a too important temperature variation, the mechanical assemblies can be weakened and engender an irreparable break. The objective of the thesis is therefore to realize and study the mechanical and structural behavior of assembly of thin layers of polymers and metals in temperature and humidity.Two types of polymers were selected for this project:1. Polyvinylidene chloride (PVDC), a commercial polymer widely used for its good barrier properties to water.2. A thermally and UV-crosslinkable acrylate oligomer synthesized in the IMMM
Shih, Sheng-Chih, and 施勝志. "The Applications of Ultrafast Laser in Microscopic Imaging:RF OBIC&SHG Microscopy." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/55135142189129102869.
Full text國立中山大學
物理學系研究所
90
In this study,we apply the broad bandwidth and high energy pulse of ultrafast laser to experiment on RF OBIC and second harmonic generation. In this paper a novel method is presented for characterizing high frequency response and behavior of ultra high-speed photosensitive semiconductor devices and the set-up is capable of generating excitation at RF bandwidths of greater than 1.8 THz. In addition,the collagen of dentine is able to generate the second harmonic in the ultraviolet region, so we develop a high performance transmission mode laser scanning microscope for obtaining SHG images of a tooth slice. We also study wavelength dependence and polarization dependence.
Rubiano, da Silva Nara. "Ultrafast Lorentz Microscopy using High-Coherence Electron Pulses." Doctoral thesis, 2019. http://hdl.handle.net/11858/00-1735-0000-002E-E628-A.
Full textVillafana, Tana Elizabeth. "Ultrafast Pump-Probe Microscopy in Cultural Heritage Research." Diss., 2015. http://hdl.handle.net/10161/9934.
Full textThe materials and working method of a painting can reveal important information about our cultural history, as well as lend the conservator the necessary knowledge for treatment options. The removal of a cross-section sample reveals the three-dimensional (3d) structure of the painting and can be used to identify materials. However, cross-section samples are destructive and provide only local information. Nonlinear optical ultrafast pump-probe microscopy, originally developed for biomedical imaging, can provide high resolution 3d images with chemical contrast. In this dissertation, I adapt pump-probe microscopy to multiple materials and applications in cultural heritage research. Pump-probe dynamics were found to be sensitive to the ratio of the two chromophores present in the precious blue pigment lapis lazuli and its synthetic analogs, ultramarines blue and violet. Virtual pump-probe cross-sections were combined with nonlinear fluorescence contrast to study differences between the interactions of paper supports with inorganic crystalline pigments and organic dyes. Multiple early Italian paintings (The Crucifixion by Puccio Capanna, The Martyrdom of St. Alexander and The Body of Christ Supported by Angels attributed to Lorenzo Lotto) were imaged in-situ, in conjunction with traditional conservation science methods, as a part of a technical case study. Thus, pump-probe microscopy offers an important new tool for gaining fundamental insights into our cultural heritage.
Dissertation
Peng, Wei-tung, and 彭偉棟. "Pump-Probe Based Ultrafast Time-Resolved Laser Scanning Microscopy." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/92504115411109677492.
Full text國立中山大學
光電工程研究所
93
Recently, lifetime imaging has become a subject of intensive research. Lifetime is an important parameter to understand the dynamics of targeted objects and its applications ranges from fluorescence decay of biological objects to relaxation of semiconductor materials and devices. Many methods, such as time-correlated single photon counting (TCSPC) and phase detection in frequency domain, were developed to measure the characteristic lifetime. These methods are now rather matured and widely applied in various studies. However, these methods are only effective for lifetime longer than 100 picoseconds due to the bandwidth limitation of high-speed electronics. For even faster temporal resolution, novel techniques that do not rely on high-speed electronics will be required. In this study, we are integrating an autocorrelator with a galvo-based laser scanning microscope to enable imaging with very high temporal resolution. The principle and technique of pump-probe is implemented through the autocorrelator. In this way, imaging based pump-probe measurements can be realized. Specifically, we have applied the experimental setup so developed in measuring fluorescent dyes and semiconductor devices.
Feist, Armin. "Next-Generation Ultrafast Transmission Electron Microscopy – Development and Applications." Thesis, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E48B-B.
Full textBormann, Reiner. "Development and characterization of an electron gun for ultrafast electron microscopy." Doctoral thesis, 2015. http://hdl.handle.net/11858/00-1735-0000-0028-867D-4.
Full textPriebe, Katharina Elisabeth. "Coherent Control and Reconstruction of Free-Electron Quantum States in Ultrafast Electron Microscopy." Thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-002E-E30D-2.
Full text"Ultrafast Femtosecond Laser Beam Shaping and Its Applications in Two-Photon Excitation Microscopy." 2016. http://repository.lib.cuhk.edu.hk/en/item/cuhk-1292485.
Full textKuo, Yung-En, and 郭永恩. "Applications of Ultrafast Lasers on Super Resolution Microscopy and Investigation of Myocyte Cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/72744340339819030368.
Full text國立陽明大學
生醫光電工程研究所
98
Ultrafast pulsed laser (pulse width from tens femtosecond i.e. 10−15 second to picoseconds i.e. 10−12 second) is a mature laser technology which developed very well in recent years, it’s multiple applications are not only in industry but also academia. In academy, the applications include ultrafast phenomena, multi-photon microscopy, photochemistry and so on. In industry, it was applied in producing and processing on high precision components. This research utilizes the characteristic of ultrafast pulse lasers and investigates the application of far-field optical super-resolution microscopy and the research of mycyte cells stimulation. First we utilize the ultrafast pulse laser as our far-field super-resolution light source. Super-resolution microscopy is the foreground of the microscopy in recent 10~20 years. Because of the conventional optical microscopy are limited by diffraction limit, it can not resolve organelle structure and molecule interaction inside the cell , these properties usually occur under tens to a few nanometer scale, however the diffraction limit is about 200 nm. The far-field optical super-resolution we studied is called STED (Stimulated Emission Depletion) which was first innovated by Dr. Stefan W. Hell in 1994, who is now doing research in Max Plank Institute. The principle is using the “stimulated emission”, as we utilize another beam to make the outer area of fluorescence molecules to be stimulated emission, then the effective emitting area become smaller, so as to break the spatial diffraction limit, it can reach tens of nanometer spatial resolution. Secondly, we utilize ultrafast laser to generate stress wave to affect several living cells, and study the effect after the mechanical stress. When an amplify femtosecond pulsed laser is focused in fluid, high intensity energy induce ablation phenomenon and create transient shockwave and bubbles simultaneously. This micron range stress wave push and shake the cells. We estimate the cell growth rate by counting the cells numbers to see if the cells stimulated by the mechanical stress or not.
(6318551), Jordan M. Snaider. "CARRIER TRANSPORT IN HYBRID LEAD HALIDE PEROVSKITES STUDIED BY ULTRAFAST PUMP-PROBE MICROSCOPY." Thesis, 2019.
Find full textGunther, Aimee Kirsten. "Ultrafast coincidence characteristics of entangled photons towards entangled two-photon absorption." Thesis, 2014. http://hdl.handle.net/10012/8234.
Full textYang, Te-chen, and 楊德振. "The Applications of Ultrafast laser in Laser Scanning Microscopy:RFOBIC and Two Photon UV Fluorescence Microscopy." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/27236912626240143267.
Full text國立中山大學
物理學系研究所
92
In this study, the characteristic properties of the ultrafast laser exhibit sufficiently in the application of RFOBIC and two-photon UV fluorescence. This laser can be used to measure photonic components with fast responding speed due to the ultrashort pulse and broad bandwidth which is RF bandwidths of greater than 1.8THz. we have demonstrated the use of a frequency-doubled femtosecond optical parametric oscillator in generating two-photon excitation that is equivalent to ultraviolet(UV) light with wavelength less than 300 nm. This capability allows observation of some amino acids and enables excitation that is only possible with wavelength in UVB range(290 nm-320 nm)
Shaheen, Basamat S. "Real-Space Imaging of Charge Carrier Dynamics in Photoactive Materials by 40 Scanning Ultrafast Electron Microscopy." Diss., 2019. http://hdl.handle.net/10754/653701.
Full textTseng, Ming-Lun, and 曾銘綸. "Nano fabrication and measurement of phase-change thin film by ultrafast laser and atomic force microscopy." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/82685684794523274472.
Full text臺灣大學
物理研究所
98
Phase change materials has different optical and electrical properties in crystalline and amorphous state, it has been applied to versatile areas such as optical data storage, phase change memory, nanolithography. In this paper, we present a laser-induced forward transfer technique to fabricate the pattern with phase change material Ge2Sb2Te5. The as-deposited Ge2Sb2Te5 alloy films on a transparent substrate are transferred to the receiver substrate after a femto-second laser pulse irradiation (wavelength is 800 nm, and pulse duration is 140 femto-second). The dots patterns are fabricated with different volume and height-width ratio by changing the laser fluence and the thickness of the donor film. The topography of receiver substrate is studied by atomic force microscopy (AFM) and the optical measure system, the transfer properties are analyzed. According to the AFM measured information, we found that the dot diameter is function of Ge2Sb2Te5 donor film thickness and laser fluence. The dot size is around 14 nm (thickness) x 1500 nm (diameter). Fabrication of patterns composed of dots deposited on the receiver substrate was measured. This technique provides a simple way to form arbitrary pattern and has potential in future production of optical components, MEMS and phase-change memory.
(6577541), Long Yuan. "Spatial and Temporal Imaging of Exciton Dynamics and transport in two-dimensional Semiconductors and heterostructures by ultrafast transient absorption microscopy." Thesis, 2019.
Find full textJagannadh, Veerendra Kalyan. "Point-of-Care High-throughput Optofluidic Microscope for Quantitative Imaging Cytometry." Thesis, 2017. http://hdl.handle.net/2005/3274.
Full textSchröder, Benjamin. "Probing Light-Matter Interactions in Plasmonic Nanotips." Doctoral thesis, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-1473-3.
Full textYalcin, Sibel Ebru. "Characterization and interactions of ultrafast surface plasmon pulses." 2010. https://scholarworks.umass.edu/dissertations/AAI3427612.
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