Publications related to Dot pattern generation using thick sinusoidal phase grating under Gaussian beam illumination

Related publications (41)

Fourier analysis of near-field patterns generated by propagating polaritons

Scattering-type scanning near-field optical microscope (s-SNOM) has become an essential tool to study polaritons—quasiparticles of light coupled to collective charge oscillations—via direct probing of their near field with a spatial resolution far beyond t ...

American Physical Society (APS)2024

Orientation-dependent two-dimensional magnonic crystal modes in an ultralow-damping ferrimagnetic waveguide containing repositioned hexagonal lattices of Cu disks

Dirk Grundler

Two-dimensional (2D) hexagonal lattices of Cu disks are shown to induce orientation-dependent magnonic crystal (MC) modes for propagating forward volume spin waves in a single-crystal yttrium iron garnet (YIG) film. The width and depth of the magnonic band ...

American Physical Society (APS)2024

Subwavelength imaging using a solid-immersion diffractive optical processor

Demetri Psaltis, Niyazi Ulas Dinç, Carlo Gigli

Phase imaging is widely used in biomedical imaging, sensing, and material characterization, among other fields. However, direct imaging of phase objects with subwavelength resolution remains a challenge. Here, we demonstrate subwavelength imaging of phase ...

Springernature2024

Coherently amplified ultrafast imaging using a free-electron interferometer

Fabrizio Carbone

Accessing the low-energy non-equilibrium dynamics of materials and their polaritons with simultaneous high spatial and temporal resolution has been a bold frontier of electron microscopy in recent years. One of the main challenges lies in the ability to re ...

Nature Publishing Group2024

Ptychographic imaging with a fiber endoscope via wavelength scanning

Demetri Psaltis, Christophe Moser

Ptychography has become a popular computational imaging method for microscopy in recent years. In the present work we employ a wavelength scanning ptychography technique enhanced by neural networks for imaging with a fiber endoscope. Illumination of the ob ...

2024

Lightning interaction with the ionosphere

Farhad Rachidi-Haeri, Marcos Rubinstein

Lightning discharges, including cloud-to-ground (CG) and intracloud (IC) lightning, are known to emit electromagnetic pulses (EMPs) in a wide frequency band ranging from few Hz up to hundreds MHz [1]. During the breakdown and ionization processes (mostly f ...

IET2023

Microstrip patch antennas with broad beamwidth

Ismael Vico Triviño

Microstrip antennas offer a broad set of advantages such as low profile, light weight, easy fabrication and low cost. As these are desirable or even critical for a broad range of applications, there has been a large interest for these antennas in the anten ...

EPFL2023

Challenges and prospects for multi-chip microlens imprints on front-side illuminated SPAD imagers

Edoardo Charbon, Claudio Bruschini, Ivan Michel Antolovic, Scott Anthony Lindner, Tommaso Milanese, Ermanno Bernasconi, Vladimir Pesic

The overall sensitivity of frontside-illuminated, silicon single-photon avalanche diode (SPAD) arrays has often suffered from fill factor limitations. The fill factor loss can however be recovered by employing microlenses, whereby the challenges specific t ...

Optica Publishing Group2023

Scalable angular spectrum propagation

Felix Wechsler

Coherent field propagation is an essential computational tool in optics with applications ranging from computational optics and optical design to iterative field reconstructions. An improvement in the computational speed of current propagation methods is t ...

Optica Publishing Group2023

Experimental demonstration of dynamic spatiotemporal structured beams that simultaneously exhibit two orbital angular momenta by combining multiple frequency lines, each carrying multiple Laguerre-Gaussian modes

Tobias Kippenberg, Maxim Karpov, Zhe Zhao

In general, there are different, relatively independent forms of orbital angular momenta at a given propagation distance, which might exhibit different dynamic spatial characteristics. One type involves a beam with a helical phase-front that rotates around ...

Optica Publishing Group2022

Nonlinear Inverse Problems in Quantitative Phase Imaging

Thanh-An Michel Pham

The topic of this thesis is the development of new algorithmic reconstruction methods for quantitative phase imaging (QPI). In the past decade, advanced QPI has emerged as a valuable tool to study label-free biological samples and uncover their 3D structur ...

EPFL2022

The application of the finite-difference time-domain (FDTD) technique to lightning studies

Farhad Rachidi-Haeri, Marcos Rubinstein

We have seen in this chapter that the FDTD method for solving Maxwell's equations is accurate and versatile in a very wide variety of applications related to lightning. One can analyze the lightning electromagnetic field propagation over distances ranging ...

IET2022

Synthesis of near-diffraction-free orbital-angular-momentum space-time wave packets having a controllable group velocity using a frequency comb

Tobias Kippenberg, Maxim Karpov, Zhe Zhao

Novel forms of light beams carrying orbital angular momentum (OAM) have recently gained interest, especially due to some of their intriguing propagation features. Here, we experimentally demonstrate the generation of near-diffraction-free two-dimensional ( ...

Optica Publishing Group2022

In vitro and in vivo NIR fluorescence lifetime imaging with a time-gated SPAD camera

Edoardo Charbon, Claudio Bruschini, Arin Can Ülkü

Near-infrared (NIR) fluorescence lifetime imaging (FLI) provides a unique contrast mechanism to monitor biological parameters and molecular events in vivo. Single-photon avalanche diode (SPAD) cameras have been recently demonstrated in FLI microscopy (FLIM ...

Optica Publishing Group2022

An Accelerated First-Order Method for Non-convex Optimization on Manifolds

Christopher Arnold Criscitiello, Nicolas Boumal

We describe the first gradient methods on Riemannian manifolds to achieve accelerated rates in the non-convex case. Under Lipschitz assumptions on the Riemannian gradient and Hessian of the cost function, these methods find approximate first-order critical ...

SPRINGER2022

Generation of OAM-carrying space-time wave packets with time-dependent beam radii using a coherent combination of multiple LG modes on multiple frequencies

Tobias Kippenberg, Maxim Karpov, Zhe Zhao

Space-time (ST) wave packets, in which spatial and temporal characteristics are coupled, have gained attention due to their unique propagation characteristics, such as propagation invariance and tunable group velocity in addition to their potential ability ...

Optica Publishing Group2022

Structured light generation by refractive-diffractive micro optical array illuminators

Maryam Yousefi

Structured light generation having broad applications in different optical fields, is the topic of this thesis. Our structured light generation strategy is based on applying periodic microoptical elements at the refraction-diffraction limit, under a focuse ...

EPFL2021

Structured light engineering using a photonic nanojet

Toralf Scharf, Maryam Yousefi

In this Letter, we present the photonic nanojet as a phenomenon in a structured light generator system that is implemented to modify the source focal spot size and emission angle. The optical system comprises a microlens array that is illuminated by a focu ...

OPTICAL SOC AMER2021

How to weave a perfect sphere with curved strips

Mark Pauly, Pedro Miguel Nunes Pereira de Almeida Reis, Francis Julian Panetta, Yingying Ren, Tian Chen, Samuel Jean Bernard Poincloux

Triaxial weaving, a craft technique that enables the generation of surfaces with tri-directional arrays of initially straight elastic strips, has long been loved by basket makers and artists seeking a combination of practical and aesthetically-pleasing str ...

American Physical Society2020

Polarization-sensitive optics diffraction tomography

Demetri Psaltis, Joowon Lim, Amirhossein Saba Shirvan

Polarization of light has been widely used as a contrast mechanism in two-dimensional (2D) microscopy and also in some three-dimensional (3D) imaging modalities. In this paper, we report the 3D tomographic reconstruction of the refractive index (RI) tensor ...

2021