85 citations · 154 across the 12 of their papers we have counts for
13 papers
Imaging extended single crystal lattice distortion fields with multi-peak Bragg ptychography
Saugat Kandel, Siddharth Maddali, Marc Allain +4
We describe a phase-retrieval-based imaging method to directly spatially resolve the vector lattice distortions in an extended crystalline sample by explicit coupling of independen…
Grain boundary migration in polycrystalline -Fe
Zipeng Xu, Yu-Feng Shen, S. Kiana Naghibzadeh +8
High energy x-ray diffraction microscopy was used to image the microstructure of -Fe before and after a 600 C anneal. These data were used to determine the areas, curvat…
A differentiable forward model for the concurrent, multi-peak Bragg coherent x-ray diffraction imaging problem
S. Maddali, T. D. Frazer, N. Delegan +12
We present a general analytic approach to spatially resolve the nano-scale lattice distortion field of strained and defected compact crystals with Bragg coherent x-ray diffraction…
A matrix-free Levenberg-Marquardt algorithm for efficient ptychographic phase retrieval
Saugat Kandel, S. Maddali, Youssef S G Nashed +3
The phase retrieval problem, where one aims to recover a complex-valued image from far-field intensity measurements, is a classic problem encountered in a range of imaging applicat…
Detector tilt considerations in high-energy Bragg coherent diffraction imaging: a simulation study
Siddharth Maddali, Marc Allain, Peng Li +2
This paper addresses three-dimensional signal distortion and image reconstruction issues in x-ray Bragg coherent diffraction imaging (BCDI) in the event of a general non-orthogonal…
General approaches for shear-correcting coordinate transformations in Bragg coherent diffraction imaging: Part 2
Peng Li, Siddharth Maddali, Anastasios Pateras +4
X-ray Bragg coherent diffraction imaging has been demonstrated as a powerful three-dimensional (3D) microscopy approach for the investigation of sub-micrometer-scale crystalline pa…
General approaches for shear-correcting coordinate transformations in Bragg coherent diffraction imaging: Part 1
Siddharth Maddali, Peng Li, Anastasios Pateras +12
In this two-part article series we provide a generalized description of the scattering geometry of Bragg coherent diffraction imaging (BCDI) experiments, the shear distortion effec…
High-energy coherent X-ray diffraction microscopy of polycrystal grains: first steps towards a multi-scale approach
Siddharth Maddali, Jun-Sang Park, Hemant Sharma +7
We present proof-of-concept imaging measurements of a polycrystalline material that integrate the elements of conventional high-energy X-ray diffraction microscopy with coherent di…
Using Automatic Differentiation as a General Framework for Ptychographic Reconstruction
Saugat Kandel, S. Maddali, Marc Allain +3
Coherent diffraction imaging methods enable imaging beyond lens-imposed resolution limits. In these methods, the object can be recovered by minimizing an error metric that quantifi…
Phase retrieval for Bragg coherent diffraction imaging at high X-ray energies
Siddharth Maddali, Marc Allain, Wonsuk Cha +6
Coherent X-ray beams with energies keV can potentially enable three-dimensional imaging of atomic lattice distortion fields within individual crystallites in bulk polycry…
Bragg Coherent Modulation Imaging: Strain- and Defect- Sensitive Single Views of Extended Samples
A. Ulvestad, W. Cha, I. Calvo-Almazan +5
Nanoscale heterogeneity (including size, shape, strain, and defects) significantly impacts material properties and how they function. Bragg coherent x-ray imaging methods have emer…
Sparse recovery of undersampled intensity patterns for coherent diffraction imaging at high X-ray energies
Siddharth Maddali, Irene Calvo-Almazan, Jonathan Almer +5
Coherent X-ray photons with energies higher than 50 keV offer new possibilities for imaging nanoscale lattice distortions in bulk crystalline materials using Bragg peak phase retri…
Topology-faithful nonparametric estimation and tracking of bulk interface networks
Siddharth Maddali, Shlomo Ta'asan, Robert M. Suter
The main focus of this paper is a nonparametric filtering technique for the estimation of interface geometry in bulk materials obtainable from modern imaging measurements. The filt…