FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W288148900> ?p ?o ?g. }

• W288148900 abstract "We present in this PhD thesis work various applications of digital holographic microscopy (DHM), an imaging technique based on coherent illumination which enables the recovery of the full complex wavefront, i.e. the amplitude and phase of a wave field which interacted with a specimen. The possibility to retrieve the phase information with DHM allows to measure surfaces with nanometric accuracy, or to employ it as an endogenous quantitative signal to assess the morphology of biological specimens. The technique has been developed during the past fifteen years to reach nowadays a mature state, where it can be used routinely for metrology applications for example. We study in this work advanced applications by taking advantage of this technique, while focusing on a specific measurement method of DHM, namely the off-axis configuration, which makes it possible to measure the complex wave field with one-shot capability through spatial encoding, thus enabling real-time detection. In a first part, we develop mathematical methods based on the fundamental model of holographic recording to suppress the so-called zero-order, which consists in intensity terms that coherent detection must suppress for complex wave retrieval. In the particular case of off-axis holography, the zero-order terms usually limit the spatial resolution because of the spatial encoding of the coherent signal. We first develop an iterative method which uses the fundamental relations between coherent and incoherent detection, in order to gradually suppress the zero order terms. In a second stage, we develop a non-iterative filtering method, based on nonlinear operators. The technique is based on the transfer to another filtering space through the use of the logarithm, and enables intrinsic suppression of the zero-order terms. Both methods present the advantage of not relying on any approximation, and are thus general for any off-axis holographic configuration. We show their applicability on various hologram types, and demonstrate that in the context of microscopy, their use can increase the spatial resolution of holography, in order to reach diffraction-limited imaging for any magnification. In a second part, we study potential applications of three-dimensional imaging through coherent detection by employing multiple acquisitions with a new scanning method. The coupling of tomographic reconstruction and quantitative phase imaging showed great potential in various published works, yielding to quantitative 3D refractive index distribution measured within biological specimens, and super-resolution imaging through synthetic aperture formalism. These methods are however still subjects to many issues, in particular due to practical limitations such as mechanical imprecision in the measurement protocols and the availability of flexible reconstruction algorithms. We study a new data acquisition method which eliminates the necessity of any scanning of the illumination pattern or object rotation during the acquisition, providing potentially a more stable acquisition protocol. We present results proving the principle of our approach by measuring the 3D refractive index distribution of pollen grain. In a third part, we applied DHM to the analysis of cell morphology and dynamics, applied in particular to neuronal cells. We couple the phase measurement with widely assessed methods such as dye probing or quantitative wide field fluorescence, in order to derive relevant biological indicators from DHM. Through the interpretation of the phase as an indicator of cell volume regulation, we derive criteria for early label-free cell death detection, where we show that cell monitoring with DHM makes it possible to detect cell non-viability at early stage by measuring deregulation mechanisms. We compare our methods with dyes for cell viability assessment, showing that DHM can detect cell death typically hours before usual dye probing procedures. We also couple the phase signal with intracellular ionic concentration imaging through fluorescence, showing that the phase measured on neuron cultures is intimately linked with ionic homeostasis and in particular transmembrane water movements accompanying ionic currents such as Ca2+ or Na+. We derive typical phase signatures related to the well-known Ca2+ bursts occurring during action potentials in neurons through stimulation with glutamate, one of the major neurotransmitters in the central nervous system." @default.
• W288148900 created "2016-06-24" @default.
• W288148900 creator A5045643072 @default.
• W288148900 date "2011-01-01" @default.
• W288148900 modified "2023-09-23" @default.
• W288148900 title "Cellular Dynamics and Three-Dimensional Refractive Index Distribution Studied with Quantitative Phase Imaging" @default.
• W288148900 doi "https://doi.org/10.5075/epfl-thesis-5100" @default.
• W288148900 hasPublicationYear "2011" @default.
• W288148900 type Work @default.
• W288148900 sameAs 288148900 @default.
• W288148900 citedByCount "0" @default.
• W288148900 crossrefType "journal-article" @default.
• W288148900 hasAuthorship W288148900A5045643072 @default.
• W288148900 hasConcept C100921725 @default.
• W288148900 hasConcept C102519508 @default.
• W288148900 hasConcept C11413529 @default.
• W288148900 hasConcept C120665830 @default.
• W288148900 hasConcept C121332964 @default.
• W288148900 hasConcept C121475858 @default.
• W288148900 hasConcept C165699331 @default.
• W288148900 hasConcept C180205008 @default.
• W288148900 hasConcept C187590223 @default.
• W288148900 hasConcept C195766429 @default.
• W288148900 hasConcept C199360897 @default.
• W288148900 hasConcept C2779843651 @default.
• W288148900 hasConcept C2780009758 @default.
• W288148900 hasConcept C2781181686 @default.
• W288148900 hasConcept C41008148 @default.
• W288148900 hasConcept C44280652 @default.
• W288148900 hasConcept C62520636 @default.
• W288148900 hasConcept C77088390 @default.
• W288148900 hasConcept C81793267 @default.
• W288148900 hasConceptScore W288148900C100921725 @default.
• W288148900 hasConceptScore W288148900C102519508 @default.
• W288148900 hasConceptScore W288148900C11413529 @default.
• W288148900 hasConceptScore W288148900C120665830 @default.
• W288148900 hasConceptScore W288148900C121332964 @default.
• W288148900 hasConceptScore W288148900C121475858 @default.
• W288148900 hasConceptScore W288148900C165699331 @default.
• W288148900 hasConceptScore W288148900C180205008 @default.
• W288148900 hasConceptScore W288148900C187590223 @default.
• W288148900 hasConceptScore W288148900C195766429 @default.
• W288148900 hasConceptScore W288148900C199360897 @default.
• W288148900 hasConceptScore W288148900C2779843651 @default.
• W288148900 hasConceptScore W288148900C2780009758 @default.
• W288148900 hasConceptScore W288148900C2781181686 @default.
• W288148900 hasConceptScore W288148900C41008148 @default.
• W288148900 hasConceptScore W288148900C44280652 @default.
• W288148900 hasConceptScore W288148900C62520636 @default.
• W288148900 hasConceptScore W288148900C77088390 @default.
• W288148900 hasConceptScore W288148900C81793267 @default.
• W288148900 hasLocation W2881489001 @default.
• W288148900 hasOpenAccess W288148900 @default.
• W288148900 hasPrimaryLocation W2881489001 @default.
• W288148900 hasRelatedWork W1509664920 @default.
• W288148900 hasRelatedWork W1527434963 @default.
• W288148900 hasRelatedWork W1588636963 @default.
• W288148900 hasRelatedWork W1974476130 @default.
• W288148900 hasRelatedWork W1992926014 @default.
• W288148900 hasRelatedWork W2000121811 @default.
• W288148900 hasRelatedWork W2037854067 @default.
• W288148900 hasRelatedWork W2051157306 @default.
• W288148900 hasRelatedWork W2078300584 @default.
• W288148900 hasRelatedWork W2130405467 @default.
• W288148900 hasRelatedWork W2199268404 @default.
• W288148900 hasRelatedWork W2203405324 @default.
• W288148900 hasRelatedWork W2293167736 @default.
• W288148900 hasRelatedWork W2513912266 @default.
• W288148900 hasRelatedWork W2910107279 @default.
• W288148900 hasRelatedWork W296752383 @default.
• W288148900 hasRelatedWork W403798697 @default.
• W288148900 hasRelatedWork W78956918 @default.
• W288148900 hasRelatedWork W80941266 @default.
• W288148900 hasRelatedWork W35586481 @default.
• W288148900 isParatext "false" @default.
• W288148900 isRetracted "false" @default.
• W288148900 magId "288148900" @default.
• W288148900 workType "article" @default.