Stokes-Mueller formalism of spectrally-resolved transmitted light in an artificial opal

We have developed a multi-mode digital imaging system which acquires images with a cooled CCD camera (Figure 1). A multiple band pass dichromatic mirror and robotically controlled filter wheels provide wavelength selection for epi-fluorescence. Shutters select illumination either by epi-fluorescence or by transmitted light for phase contrast or DIC. Many of our experiments involve investigations of spindle assembly dynamics and chromosome movements in live cells or unfixed reconstituted preparations in vitro in which photodamage and phototoxicity are major concerns. As a consequence, a major factor in the design was optical efficiency: achieving the highest image quality with the least number of illumination photons. This principle applies to both epi-fluorescence and transmitted light imaging modes. In living cells and extracts, microtubules are visualized using X-rhodamine labeled tubulin. Photoactivation of C2CF-fluorescein labeled tubulin is used to locally mark microtubules in studies of microtubule dynamics and translocation. Chromosomes are labeled with DAPI or Hoechst DNA intercalating dyes.

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Three dimensional deblurring of transmitted-light brightfield micrographs

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100148654 ◽

1993 ◽

Vol 51 ◽

pp. 564-565

Author(s):

Santosh Bhattacharyya

Keyword(s):

Image Reconstruction ◽

Three Dimensional ◽

Transmitted Light ◽

Reconstruction Algorithms ◽

3D Image Reconstruction ◽

Structural Details ◽

Spread Function ◽

Early Testing ◽

Linearized Model ◽

Image Reconstruction Algorithms

Three dimensional microscopic structures play an important role in the understanding of various biological and physiological phenomena. Structural details of neurons, such as the density, caliber and volumes of dendrites, are important in understanding physiological and pathological functioning of nervous systems. Even so, many of the widely used stains in biology and neurophysiology are absorbing stains, such as horseradish peroxidase (HRP), and yet most of the iterative, constrained 3D optical image reconstruction research has concentrated on fluorescence microscopy. It is clear that iterative, constrained 3D image reconstruction methodologies are needed for transmitted light brightfield (TLB) imaging as well. One of the difficulties in doing so, in the past, has been in determining the point spread function of the system.We have been developing several variations of iterative, constrained image reconstruction algorithms for TLB imaging. Some of our early testing with one of them was reported previously. These algorithms are based on a linearized model of TLB imaging.

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Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability

10.26434/chemrxiv.6552743 ◽

2019 ◽

Cited By ~ 1

Author(s):

Theodoros Tsoulos ◽

Supriya Atta ◽

Maureen Lagos ◽

Michael Beetz ◽

Philip Batson ◽

...

Keyword(s):

Single Particle ◽

Structural Complexity ◽

Field Enhancement ◽

Hot Electron ◽

Structure Property ◽

Plasmon Band ◽

Gold Nanostars ◽

Wide Range ◽

Particle Level ◽

Spectrally Resolved

<div>Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags or phototherapeutic agents, or to design novel hot-electron based photocatalysts. From a fundamental standpoint, they represent important tunable platforms to study the dependence of hot carrier energy and dynamics on plasmon band intensity and position. Toward the realization of these platforms, holistic approaches taking into account both theory and experiments to study the fundamental behavior of these</div><div>particles are needed. Arguably, the intrinsic difficulties underlying this goal stem from the inability to rationally design and effectively synthesize nanoparticles that are sufficiently monodispersed to be employed for corroborations of the theoretical results without the need of single particle experiments. Herein, we report on our concerted computational and experimental effort to design, synthesize, and explain the origin and morphology-dependence of the plasmon modes of a novel gold nanostar system, with an approach that builds upon the well-known plasmon hybridization model. We have synthesized monodispersed samples of gold nanostars with finely tunable morphology employing seed-mediated colloidal protocols, and experimentally observed narrow and spectrally resolved harmonics of the primary surface plasmon resonance mode both at the single particle level (via electron energy loss spectroscopy) and in ensemble (by UV-Vis and ATR-FTIR spectroscopies). Computational results on complex anisotropic gold nanostructures are validated experimentally on samples prepared colloidally, underscoring their importance as ideal testbeds for the study of structure-property relationships in colloidal nanostructures of high structural complexity.</div>

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Failure Analysis and Defect Inspection of Electronic Devices by High-Resolution Cathodoluminescence

ISTFA 2017: Conference Proceedings from the 43rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2017p0349 ◽

2017 ◽

Author(s):

C. Monachon ◽

M.S. Zielinski ◽

D. Gachet ◽

S. Sonderegger ◽

S. Muckenhirn ◽

...

Keyword(s):

Failure Analysis ◽

Electronic Materials ◽

Electronic Devices ◽

Optical Emission ◽

Large Field ◽

Nanometer Scale ◽

Defect Analysis ◽

Defect Inspection ◽

Spectrally Resolved ◽

Non Destructive

Abstract Quantitative cathodoluminescence (CL) microscopy is a new optical spectroscopy technique that measures electron beam-induced optical emission over large field of view with a spatial resolution close to that of a scanning electron microscope (SEM). Correlation of surface morphology (SE contrast) with spectrally resolved and highly material composition sensitive CL emission opens a new pathway in non-destructive failure and defect analysis at the nanometer scale. Here we present application of a modern CL microscope in defect and homogeneity metrology, as well as failure analysis in semiconducting electronic materials

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Photon Emission Spectral Signatures of AlGaN/GaN HEMT for Functional and Reliability Analysis

ISTFA 2008: Conference Proceedings from the 34th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2008p0220 ◽

2008 ◽

Author(s):

Arkadiusz Glowacki ◽

Christian Boit ◽

Richard Lossy ◽

Joachim Würfl

Keyword(s):

Reliability Analysis ◽

Gate Voltage ◽

Near Infrared ◽

Photon Emission ◽

Electrical Characterization ◽

Spectral Signatures ◽

Operating Modes ◽

Gan Hemt ◽

Spectrally Resolved ◽

Performance Variations

Abstract Non-degraded and degraded AlGaN/GaN HEMT devices have been characterized electrically and investigated in various operating modes using integral and spectrally resolved photon emission (PE). In degraded devices the PE dependence on the gate voltage differs from the non-degraded devices. Various types of dependencies on the gate voltage have been identified when investigating local degradation sites. PE spectroscopy was performed at various bias conditions. For both devices broad spectra have been obtained in a wavelength regime from visible to near-infrared, including local performance variations. Signatures of the degradation have been determined in the electrical characterization, in integral PE distribution and in the PE spectrum.

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