Single-View Holographic Volumetric 3D Printing with Coupled Differentiable Wave-Optical and Photochemical Optimization

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Quantitative measurements of electric fields at the mesoscale are essential for understanding and optimizing the performance of modern devices. However, achieving this using electron microscopy techniques is challenging due to the coexistence of electrostatic and diffraction-related contrast resulting from electron beam interactions with the material. This thesis investigates the capabilities and limitations of pixelated differential phase contrast (DPC) in scanning transmission electron microscopy for quan

In this study we present, to the best of our knowledge, the first three-dimensional (3D) reconstruction of an upward lightning flash using combined very high frequency (VHF) interferometric and high-speed camera (HSC) observations. Based on this reconstruction, we estimate the 3D velocities of different pulse fronts along the channel branches. Comparable 3D reconstructions have previously been reported for downward lightning flashes [1].The Mt. Säntis Lightning Research Facility [2], located in the Appenzel

Electron ptychography revolutionized materials science microscopy by achieving record-breaking resolutions through phase retrieval algorithms, but its application to radiation-sensitive biological specimens remains largely unexplored. This thesis pioneers the application of 4D-STEM ptychography to frozen hydrated biological specimens, where electron doses must remain substantially low to prevent radiation damage, orders of magnitude lower than materials science applications. We developed an automated 4D-STE

Abstract. This work extends our initial proof-of-concept via emulations on the benefits of relative spatial constraints between imagery and lidar point clouds in a factor graph based optimization with satellite positioning (GNSS) and raw inertial readings (Mouzakidou et al., 2025). Here, we demonstrate practically the automatic extraction and integration of 2D-3D correspondences established in the 3D domain within rough natural terrain flown over by an aircraft with sensors of high quality. We show that con

Technologies of the body that support the documentation and transmission of intangible and embodied dimensions of living cultures are vital to traditions of reperformance such as reenactment. This chapter explores how innovations in computational and experimental museology are bringing marginalized corporeal experiences into museums. Working in collaboration with communities of practice, researchers spanning these two fields have conceived novel digital reenactment approaches in tandem with media artists an

In this paper, we investigate the potential of image-to-image translation (I2I) techniques for transferring realism to 3D-rendered facial images in the context of Face Recognition (FR) systems. The primary motivation for using 3D-rendered facial images lies in their ability to circumvent the challenges associated with collecting large real face datasets for training FR systems. These images are generated entirely by 3D rendering engines, facilitating the generation of synthetic identities. However, it has b

Wavelength‐tunable pulsed lasers have garnered significant research interest due to their critical role in applications requiring precise spectral matching, such as wavelength‐division multiplexing and spectroscopic analysis. Although recent hybrid architectures integrating saturable absorbers with wavelength‐selective components have enabled notable progress, these systems remain constrained by two fundamental challenges: excessive coupling losses and complex alignment procedures. Here, a compact wavelengt

Linear crystal defects called dislocations are one of the most fascinating concepts in materials science that govern mechanical and optoelectronic properties of many materials across a broad range of application. Three-dimensional (3-D) study of dislocation network is in principle accessible by conventional tomographic and stereoscopic techniques in Transmission Electron Microscopy (TEM). In these techniques in general the need to tilt the specimen for acquiring image series over large tilt ranges remain ho

The correction of field curvature by space or time multiplexing enables the design of a very simple imaging system for mobile device. Here, the optical design is presented and methods to correct the field curvature are discussed. This imaging system can be fabricated with wafer-level processes enabling large-scale and low cost production

In vivo fetal magnetic resonance imaging provides a unique approach for the study of early human brain development [1]. In utero cerebral morphometry could potentially be used as a marker of the cerebral maturation and help to distinguish between normal and abnormal development in ambiguous situations. However, this quantitative approach is a major challenge because of the movement of the fetus inside the amniotic cavity, the poor spatial resolution provided by very fast MRI sequences and the partial volume

Many biological objects are mainly transparent and weakly scattering, thus a promising (and already widely used) way of imaging them consists in considering optical refractive index variations. The method proposed here permits 3D imaging of the refractive index distribution with a tomographic approach. Usually, the classical Radon transform does not sufficiently take into account the physical interaction between light and biological cells, therefore diffraction has to be considered.

With the use of a Bessel-like illumination beam produced by an axicon lens an extended depth of field can be achieved. The resulting illumination pattern exhibits a strong central lobe extending over 300um along the optical axis without diffraction. Here we present a fast digital focusing algorithm to correct for remaining out of focus artifacts, manifest in sidelobes for out of focus scatterers, due to the decoupled Gaussian detection. The waist of the detection in the focal plane is 2.1um, with a Rayleigh

We present a novel Fourier domain method for microscopic imaging - so- called k-microscopy - with lateral resolution independent of the detection numerical aperture. The concept is based on sample illumination by a lateral fringe- pattern of varying spatial frequency, which probes the lateral spatial frequency or k- spectrum of the sample structure. The illumination pattern is realized by interference of two collimated coherent beams. Wavelength tuning is employed for modulation of the fringe spacing. The u

Biomimetic apatite coatings were obtained by soaking chemically treated titanium in SBF with different HCO3- concentration. XRD, FTIR and Raman analyses were used to characterize phase composition and degree of carbonate substitution. The microstructure, elemental composition and preferred alignment of biomimetically precipitated crystallites were characterized by cross-sectional TEM analyses. According to XRD, the phase composition of precipitated coatings on chemically pre-treated titanium after exposure

This work concerns the developing of new perceptual metrics for 3D watermarking quality assessment. Any water- marking algorithm, to be effective, requires that the distortions is inevitably introduces into the watermarked media is imperceptible. This requirements is particularly severe for watermarking of 3D objects where the visual quality of the original model has to be preserved, i.e. the visual aspect of the watermarked object have to be the same of the original one. Several methods based on the knowle

In this thesis, we describe new approaches and methods for reconstructing complex-valued wave fields from digital holograms. We focus on Fresnel holograms recorded in an off-axis geometry, for which operational real-time acquisition setups readily exist. The three main research directions presented are the following. First, we derive the necessary tools to port methods and concepts of wavelet-based approaches to the field of digital holography. This is motivated by the flexibility, the robustness, and the u

Low coherence, digital holographic microscopy (LCDHM) is a new 3D imaging technique combining the advantages of digital holographic microscopy with those of reduced coherence interferometry. This gives the possibility to perform tomography of 3D objects while maintaining the excellent performances of DHM. A tomographic depth resolution of 11 mum has been achieved as a proof of principle. Images of the epithelial cells of the porcine cornea are presented.

An X-ray diffraction experiment on multilamellar membranes incorporated into an X-ray waveguide structure is reported. In the device, the lipid bilayers are confined to one side by the silicon substrate and to the other side by an evaporated thin metal cap layer. Shining a highly brilliant X-ray beam onto the system, resonantly enhanced, precisely defined and clearly distinguishable standing-wavefield distributions (modes) are excited. The in-plane structure of the acyl chain ordering is then studied by gra

Off-axis holograms recorded with a CCD camera are numerically reconstructed with a calculation of scalar diffraction in the Fresnel approximation. We show that the zero order of diffraction and the twin image can be digitally eliminated by means of filtering their associated spatial frequencies in the computed Fourier transform of the hologram. We show that this operation enhances the contrast of the reconstructed images and reduces the noise produced by parasitic reflections reaching the hologram plane wit

In the course of 1998, the Spectromicroscopy beamline at ELETTRA completed commissioning and succeeded in performing its first test experiments. The beamline is designed to perform photoemission experiments with high spatial resolution, which is obtained by focusing the radiation in a small spot on the sample by means of a multilayer-coated Schwarzschild Objective. Three objectives are currently available; these operate at photon energies of 74, 95, and 110 eV. A review is presented of the performances achi

Single-View Holographic Volumetric 3D Printing with Coupled Differentiable Wave-Optical and Photochemical Optimization

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Probing (ferro)electric fields using pixelated differential phase contrast imaging aided by precession

Combining VHF and optical observations to reconstruct an upward flash

Coherent Diffractive Imaging in Biological Transmission Electron Microscopy

Extraction of Image-to-Lidar Correspondences and their Impact on Optimal Sensor Fusion

Reenactment

Synthetic to Authentic: Transferring Realism to 3D Face Renderings for Boosting Face Recognition

Wavelength Tunable Pulsed Lasers Enabled by a Versatile Metafiber Functioning as Both Saturable Absorber and Filter

Three-dimensional electron imaging of dislocations from a single sample tilt

Space and time multiplexing for field curvature correction in miniature imaging systems

Quantitative morphometry analysis of the fetal brain using clinical MR imaging

Diffraction tomography for biological cells imaging using digital holographic microscopy

Enhancement of extended depth of field by digital focusing

k-Microscopy: resolution beyond the diffraction limit

Biomimetic apatite coatings - Carbonate substitution and preferred growth orientation

Watermarked 3D Object Quality Assessment

On Fresnelets, interference fringes, and digital holography

Low coherence digital holographic tomography

Waveguide-enhanced scattering from thin biomolecular films

Spatial filtering for zero-order and twin-image elimination in digital off-axis holography

Spectromicroscopy beamline at ELETTRA: Performances achieved at the end of commissioning