Publications associées à Coherence and wavefront characterization of Si-111 monochromators using double-grating interferometry

3D diffractive optics for linear interconnects and nonlinear processing

The optical domain presents potential avenues for enhancing both computing and communication due to its inherent properties of bandwidth, parallelism, and energy efficiency. This research focuses on harnessing 3-Dimensional (3D) diffractive optics for nove ...

EPFL2024

A compact approach to higher-resolution resonant inelastic x-ray scattering detection using photoelectrons

Henrik Moodysson Rønnow, Markus Scholz

The detection of inelastically scattered soft x-rays with high energy resolution usually requires large grating spectrometers. Recently, photoelectron spectrometry for analysis of x-rays (PAX) has been rediscovered for modern spectroscopy experiments at sy ...

Iop Publishing Ltd2024

Collimation simulations for the FCC-ee

Tatiana Pieloni, Félix Simon Carlier, Guillaume Clément Broggi, Milica Rakic, Giovanni Iadarola, Bruce Roderik

The collimation system of the Future Circular Collider, operating with leptons (FCC-ee), must protect not only the experiments against backgrounds, but also the machine itself from beam losses. With a 17.8 MJ stored energy of the electron and positron beam ...

Iop Publishing Ltd2024

Resonators with tailored optical path by cascaded-mode conversions

Ileana-Cristina Benea-Chelmus, Marco Piccardo

Optical resonators enable the generation, manipulation, and storage of electromagnetic waves. The physics underlying their operation is determined by the interference of electromagnetic waves, giving rise to the resonance spectrum. This mechanism causes th ...

Nature Portfolio2023

Sub-kHz-Linewidth External-Cavity Laser (ECL) With Si3N4 Resonator Used as a Tunable Pump for a Kerr Frequency Comb

Tobias Kippenberg, Junqiu Liu

Combining optical gain in direct-bandgap III-V materials with tunable optical feedback offered by advanced photonic integrated circuits is key to chip-scale external-cavity lasers (ECL), offering wideband tunability along with low optical linewidths. Exter ...

IEEE Institute of Electrical and Electronics Engineers2023

Reconstruction of Angstrom resolution exit-waves by the application of drift-corrected phase-shifting off-axis electron holography

Thierry Meyer, Victor Carle Adrien Boureau

Phase-shifting electron holography is an excellent method to reveal electron wave phase information with very high phase sensitivity over a large range of spatial frequencies. It circumvents the limiting trade-off between fringe spacing and visibility of s ...

Elsevier2023

Nonlinear Integrated Photonics for Ranging Applications

Anton Lukashchuk

This thesis explores the application of recent advances in integrated photonics to the field of light detection and ranging (LiDAR). The progress in photonic integration allows for unprecedented levels of light manipulation on micrometer scales through the ...

EPFL2023

Space-time wave packets with reduced divergence and tunable group velocity generated in free space after multi-mode fiber propagation

Tobias Kippenberg, Hao Song, Maxim Karpov, Xinzhou Su

Previously, space-time wave packets (STWPs) have been gen-erated in free space with reduced diffraction and a tunable group velocity by combining multiple frequency comb lines each carrying a single Bessel mode with a unique wave num-ber. It might be poten ...

Optica Publishing Group2023

A chip-scale second-harmonic source via self-injection-locked all-optical poling

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Edgars Nitiss, Marco Clementi

Second-harmonic generation allows for coherently bridging distant regions of the optical spectrum, with applications ranging from laser technology to self-referencing of frequency combs. However, accessing the nonlinear response of a medium typically requi ...

2023

Domain Imaging and Switching Dynamics in BaTiO3-Based Photonic Integrated Devices

Jacqueline Geler Kremer

Keeping up with our constantly connected lifestyle of instant messages and video streaming has its repercussions. Data centers have been gobbling up resources becoming a significant share of the energy used worldwide. To keep up with demand and curb the en ...

EPFL2023

Optical and mid-infrared line emission in nearby Seyfert galaxies

Michaela Hirschmann

Line ratio diagnostics provide valuable clues as to the source of ionizing radiation in galaxies with intense black hole accretion and starbursting events, such as local Seyfert galaxies or galaxies at the peak of their star formation history. We aim to pr ...

2023

High sensitivity, incoherent differential imaging

Chiara Bonati

Microscopic visualisation of optically transparent samples has been a topic of interest for several decades. Features such as density or chemical composition can influence the optical phase of transmitted light, and phase contrast can reveal these structur ...

EPFL2022

Glass-in-glass infiltration for 3D micro-optical composite components

Yves Bellouard, Andreas Mortensen, Jérôme Faist, Enrico Casamenti, Luciano Borasi, Gözden Torun, Mathieu Bertrand

Chalcogenide glass exhibits a wide transmission window in the infrared range, a high refractive index, and nonlinear optical properties; however, due to its poor mechanical properties and low chemical and environmental stability, producing three-dimensiona ...

2022

Optical Diffraction Tomography Using Nearly In-Line Holography with a Broadband LED Source

Demetri Psaltis, Ahmed Ayoub, Abhijit Roy

We present optical tomography methods for a 3D refractive index reconstruction of weakly scattering objects using LED light sources. We are able to record holograms by minimizing the optical path difference between the signal and reference beams while sepa ...

MDPI2022

SYNAPSE: An international roadmap to large brain imaging

Giorgio Margaritondo

Since 2020, synchrotron radiation facilities in several Asia-Pacific countries have been collaborating in a major project called "SYNAPSE"(Synchrotrons for Neuroscience: an Asia-Pacific Scientific Enterprise). They use x-ray imaging to attack in a coordina ...

ELSEVIER2022

Dual chirped microcomb based parallel ranging at megapixel-line rates

Tobias Kippenberg, Maxim Karpov, Junqiu Liu, Anton Lukashchuk

Photonic integrated systems can be harnessed for fast and efficient optical telecommunication and metrology technologies. Here the authors develop a dual-soliton microcomb technique for massively parallel coherent laser ranging that requires only a single ...

Nature Portfolio2022

Beware of beam damage under reaction conditions: X-ray induced photochemical reduction of supported VOx catalysts during in situ XAS experiments

Oliver Kröcher, Davide Ferri, Anna Zabilska, Olga Safonova

In situ X-ray absorption spectroscopy (XAS) is a powerful technique for the investigation of heterogeneous catalysts and electrocatalysts. The obtained XAS spectra are usually interpreted from the point of view of the investigated chemical processes, there ...

ROYAL SOC CHEMISTRY2022

Low-noise frequency-agile photonic integrated lasers for coherent ranging

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Wenle Weng, Andrey Voloshin, Jijun He, Anat Siddharth, Viacheslav Snigirev, Vladimir Shadymov

Stable and tunable integrated lasers are fundamental building blocks for applications from spectroscopy to imaging and communication. Here the authors present a narrow linewidth hybrid photonic integrated laser with low frequency noise and fast linear wave ...

Nature Portfolio2022

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, Daniel Necesal

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