Publications associées à Determination of local refractive index variations in thin films by heterodyne interferometric scanning near-field optical microscopy

All-Dielectric Nanophotonic via Glass Fluid Instabilities

In this thesis work, we propose to exploit an innovative micro/nano-fabrication process, based on controlled fluid instabilities of a thin viscous film of chalcogenide glass. Amorphous selenium and arsenic triselenide were used in this thesis work, and com ...

EPFL2024

Nanostructure and Optical Property Tailoring of Zinc Tin Nitride Thin Films through Phenomenological Decoupling: A Pathway to Enhanced Control

Aïcha Hessler-Wyser, Johann Michler, Amit Sharma, Daniele Casari, Caroline Hain, Thomas Nelis

This work addresses the need for precise control of thin film sputtering processes to enable thin film material tailoring on the example of zinc tin nitride (ZTN) thin films deposited via microwave plasma-assisted high power reactive magnetron sputtering ( ...

Amer Chemical Soc2024

Lithium tantalate photonic integrated circuits for volume manufacturing

Tobias Kippenberg, Kai Huang, Chen Yang, Mikhail Churaev, Xinru Ji, Yang Chen, Zihan Li, Alisa Davydova, Xi Wang, Junyin Zhang

Electro-optical photonic integrated circuits (PICs) based on lithium niobate (LiNbO3) have demonstrated the vast capabilities of materials with a high Pockels coefficient1,2. They enable linear and high-speed modulators operating at complementary metal–oxi ...

2024

Femtosecond laser-induced modifications and self-organization in complex glass systems

Gözden Torun

Ultrashort laser pulses, i.e., pulses emitted shorter than a picosecond, can tailor material properties by introducing permanent modifications locally in three dimensions. Remarkably, under a certain exposure condition, these modifications are accompanied ...

EPFL2023

Exploring Novel Modalities for Optical Diffraction Tomography

Amirhossein Saba Shirvan

In the past decade, optical diffraction tomography has gained a lot of attention for its ability to create label-free three-dimensional (3D) images of the refractive index distribution of biological samples using scattered fields measured through holograph ...

EPFL2023

van der Waals Materials for Overcoming Fundamental Limitations in Photonic Integrated Circuitry

Arslan Mazitov

With the advance of on-chip nanophotonics, there is a high demand for high-refractive-index and low-loss materials. Currently, this technology is dominated by silicon, but van der Waals (vdW) materials with a high refractive index can offer a very advanced ...

AMER CHEMICAL SOC2023

Nanoscale local modification of PMMA refractive index by tip-enhanced femtosecond pulsed laser irradiation

Mihai Adrian Ionescu

Tip-enhanced optical effects have enabled a wide palette of nanoscale investigation techniques and recently they were successfully used to modify and manipulate matter with nanoscale spatial resolution. We contribute to this latter area by reporting a viab ...

ELSEVIER2023

Dielectric metasurfaces and their applications for optical biosensing

Yasaman Jahani

Over the past century, our understanding of life has been focused on its most fundamental building blocks: molecules. Biological molecules, such as proteins found in blood, other body fluids, or tissues, are excellent guides to identifying a normal or abno ...

EPFL2023

Practical computational imaging by use of spatiotemporal light modulation: from simulations to applications in biological microscopy

François Thierry M Marelli

Optical microscopy is an essential tool for biologists, who are often faced with the need to overcome the spatial and temporal resolution limitations of their devices to capture finer details. As upgrading imaging hardware is expensive, computational metho ...

EPFL2023

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

III-V Nitride Semiconductors Deposited At Low Temperature For Photovoltaic Applications

Jonathan Emanuel Thomet

This thesis reports on the study and use of low temperature processes for the deposition of indium gallium nitride (InGaN) thin films in order to alleviate some of the present drawbacks of its monolitic deposition on silicon for photovoltaic applications. ...

EPFL2023

Mitochondrial nanomotion measured by optical microscopy

Sandor Kasas, María Inés Villalba, Priyanka Parmar

Nanometric scale size oscillations seem to be a fundamental feature of all living organisms on Earth. Their detection usually requires complex and very sensitive devices. However, some recent studies demonstrated that very simple optical microscopes and de ...

Frontiers Media SA2023

Aperture-Controlled Fabrication of All-Dielectric Structural Color Pixels

Philippe Renaud, Arnaud Bertsch, Olivier Martin, Daniel Migliozzi, Clémentine Sophie Sarah Lipp, Evgenii Glushkov, Hsiang-Chu Wang, Audrey Zoé Marie Jacquillat

While interference colors have been known for a longtime, conventionalcolor filters have large spatial dimensions and cannot be used tocreate compact pixelized color pictures. Here we report a simple yetelegant interference-based method of creating microsc ...

AMER CHEMICAL SOC2023

Silica aerogel as rear reflector in silicon heterojunction solar cells for improved infrared response

Deniz Türkay

Silicon (Si), with its indirect bandgap, is a non-ideal absorber. Thus, various strategies to boost silicon solar cells' efficiency, including advanced texturing, multilayer anti-reflecting coating, and rear reflectors are utilized. Dielectrics, deposited ...

ELSEVIER2023

Advanced Techniques in Optical Diffraction Tomography

Ahmed Bassam Sayed Ayoub Mohamed Emam

In this thesis, we study the 3 challenges described above. First, we study different reconstruction techniques and assess the fidelity of each reconstruction results by means of structured illumination and phase conjugation. By reconstructing the 3D refrac ...

EPFL2022

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

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

Structural and photophysical investigation of single-source evaporation of CsFAPbI(3) and FAPbI(3) perovskite thin films

Mohammad Khaja Nazeeruddin, Hiroyuki Kanda, Nadja Isabelle Desiree Klipfel, Albertus Adrian Sutanto, Maria Cristina Momblona Rincón

Thermal vacuum deposition is a stimulating technique for upscaling perovskite solar cells. However, the operational complexity of multisource vapor deposition (MSVD) and achieving stoichiometric perovskite layers may impede its implementation. The single-s ...

Royal Society of Chemistry2022

Probing material absorption and optical nonlinearity of integrated photonic materials

Tobias Kippenberg, Junqiu Liu, Guanhao Huang

Optical microresonators with high quality (Q) factors are essential to a wide range of integrated photonic devices. Steady efforts have been directed towards increasing microresonator Q factors across a variety of platforms. With success in reducing microf ...

Nature Portfolio2022

Large Anomalous Nernst Angle in Co2MnGa Thin Film

Jean-Philippe Ansermet, Simon Granville, Haiming Yu, Song Liu, Junfeng Hu, Yao Zhang

The new trends for anomalous Nernst effect (ANE)-based thermoelectric devices require materials with large ANE values to realize the scalable generation of voltage. Recently, very large ANE values have been observed in single crystals of some novel magneti ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022