Ptychography with multiple wavelength illumination

Wei, Xukang; Urbach, Paul

doi:10.1364/oe.27.036767

Cited by 9 publications

(5 citation statements)

References 43 publications

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“…For each of these 2D projection reconstructions, the complex object transmission function contains both the amplitude and phase shift information. Then with the phase shift information, all the projections were unwrapped, aligned, and reconstructed using the open-sourced MATLAB package [54,55] developed by cSAXS beamline at Paul Scherrer Institute (PSI), [57] to give the final 3D tomograms. The ED (e Å À3 ) was then calculated from the phase tomograms using the relation as described elsewhere.…”

Section: Morphological Analysis and Imaging Techniquesmentioning

confidence: 99%

Carbon Nanotubes Facilitate Silk Hierarchical Assembly by Dry Drawing

Wan,

Farr,

et al. 2024

Small Structures

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Biologically derived hierarchical structural materials not only boast energy‐efficient processing but also exhibit impressive mechanical performance. Silk stands as the gold standard in hierarchical fiber production, leveraging a unique combination of advantages. Nevertheless, the artificial replication of silk poses technical challenges related to precision processing and comprehensive molecular control. To address such issues, this study investigates the hierarchical assembly of solid regenerated silk in an air atmosphere, facilitated by the incorporation of carbon nanotube (CNT) seeding. Results obtained highlight that this CNT seeding facilitates multiscale structure development in response to post‐spin tensile stress. Such CNT bridged structure assembly bypasses some natural processing control variables (pH, ions) and the necessary solvent immersed state for conventional silk post‐drawing. Combining secondary electron hyperspectral imaging and 3D synchrotron X‐ray ptychotomography, this study reports silk protein conversion from a disordered as‐spun state to a longitudinal orientated semi‐crystalline nano structure during drawing. The development of microscale structure during the drawing process is attributed to the presence of CNTs, yielding mechanical properties comparable to, and frequently surpassing, those exhibited by native fibers. These findings collectively propose a framework for exploring novel processing routes and offer a practical means controlling self‐assembly in silk materials.

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Section: Morphological Analysis and Imaging Techniquesmentioning

confidence: 99%

Carbon Nanotubes Facilitate Silk Hierarchical Assembly by Dry Drawing

Wan,

Farr,

et al. 2024

Small Structures

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“…(16), we developed and implemented Algorithm 1 as described in the Appendix. To mitigate ambiguity problems of ptychography [27], e.g., the global phase shift, the conjugate reconstruction, and the raster grid pathology, it is assumed that the probe used in the Monte Carlo experiment is known. To shorten the computation time and to improve the convergence, the conjugate-gradient method [40,57] is implemented in Algorithm 1.…”

Section: Monte Carlo Analysismentioning

confidence: 99%

“…During the last two decades, ptychography has been successfully demonstrated with x-ray radiation sources [11,16,17], electron beams [18], and visible light sources [19]. More recently, many extensions of ptychography have been proposed, including Fourier ptychography [20][21][22], spatially partial coherent ptychography [23][24][25], broadband ptychography [26,27], three-dimensional (3D) ptychography [28][29][30], on-the-fly scanning ptychograhy [31,32], and interference probe ptychography [33].…”

Section: Introductionmentioning

confidence: 99%

Cramér-Rao lower bound and maximum-likelihood estimation in ptychography with Poisson noise

2020

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We investigate the performance of ptychography with noisy data by analyzing the Cramér-Rao lower bound. The lower bound of ptychography is derived and numerically computed for both top-hat plane wave and structured illumination. The influence of Poisson noise on the ptychography reconstruction is discussed. The computation result shows that, if the estimator is unbiased, the minimum variance for Poisson noise is mostly determined by the illumination power and the transmission function of the object. Monte Carlo analysis is conducted to validate our calculation results for different photon flux numbers. Furthermore, the performance of the maximum-likelihood method and the approach of amplitude-based cost-function minimization is studied in the Monte Carlo analysis.

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“…It has been shown that mixed states can be deconvolved, and partial decoherence can be compensated for in advanced reconstruction algorithms, such as ptychographic information multiplexing (PIM) [12,16,17]. PIM extended ptychography to allow for simultaneous imaging with multiple wavelength probe illuminations without significant degradation to reconstruction quality as measured by resolution and signal to noise ratio (SNR) [18]. While these recent developments in advanced ptychographic phase retrieval algorithms are promising for plasma imaging applications, they require transverse scanning of the object thus preventing the possibility of imaging transient, non-reproducible objects.…”

Section: Arxiv:200901337v1 [Physicsoptics] 2 Sep 2020mentioning

confidence: 99%

Wavelength-Multiplexed Single-Shot Ptychography

Barolak

Goldberger

Bellouard

et al. 2020

Conference on Lasers and Electro-Optics

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Diagnostics capable of interrogating dynamics in harsh environments such as plasma have remained essentially unchanged in recent decades. Developments in advanced microscopy techniques will improve our understanding of the physics involved in these events. Recently developed single-shot ptychography (SSP) provides a pathway towards sophisticated plasma metrologies. Here we introduce wavelength-multiplexed single-shot ptychography (WM-SSP), which allows for hyperspectral, spatially and temporally resolved phase and amplitude contrast imaging. Furthermore, we introduce a novel probe constraint common to all wavelength multiplexed modalities in the single-shot geometry and present modifications to SSP that improve reconstruction fidelity and robustness. WM-SSP was experimentally realized and simulations show the technique's ability to deconvolve the electron and neutral densities within the plasma. WM-SSP will pave the way to a new generation of quantitative plasma imaging techniques.

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Ptychography with multiple wavelength illumination

Cited by 9 publications

References 43 publications

Carbon Nanotubes Facilitate Silk Hierarchical Assembly by Dry Drawing

Carbon Nanotubes Facilitate Silk Hierarchical Assembly by Dry Drawing

Cramér-Rao lower bound and maximum-likelihood estimation in ptychography with Poisson noise

Wavelength-Multiplexed Single-Shot Ptychography

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