Publications associées à Demonstration of superprism effect in silicon pillar 2-D photonic crystal infiltrated with liquid crystals

Parametric Wavelength Conversion in Waveguiding Structures: Efficiency, Bandwidth and Polarization

Photonics integrated circuits are a promising solution for the growing demands of data transmission and future system-on-chip technologies. Within this context, nonlinear optical interactions offer unique opportunities for all-optical processing, sampling, ...

EPFL2024

Local vs. cooperative: Unraveling glass transition mechanisms with SEER

Matthieu Wyart, Wencheng Ji

Which phenomenon slows down the dynamics in supercooled liquids and turns them into glasses is a long-standing question of condensed matter. Most popular theories posit that as the temperature decreases, many events must occur in a coordinated fashion on a ...

National Academy of Sciences2024

Murunskite - a new class of functional material

Davor Tolj

The subject of the present work is discovery and in-depth characterization of a new class of functional materials. Tuning of the bond polarity and orbital occupation with a goal of establishing balance between localization and delocalization of electrons - ...

EPFL2023

Polariton lasing in AlGaN microring with GaN/AlGaN quantum wells

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté

Microcavity polaritons are strongly interacting hybrid light-matter quasiparticles, which are promising for the development of novel light sources and active photonic devices. Here, we report polariton lasing in the UV spectral range in microring resonator ...

AIP Publishing2023

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

Direct Observation of the Phase Transition in C60 Fullerene

Chengcheng Yan

In the third study, the order-disorder phase transition of single-crystal C60 is studied using time-resolved electron microscopy. Solid C60 undergoes a first-order phase transition upon heating to 260 K. This is a structural transition from the low-tempera ...

EPFL Infoscience2023

Ultra low quantum decoherence nano-optomechanical systems

Mohammadjafar Bereyhi

Thermal motion of a room-temperature mechanical resonator typically dominates the quantum backaction of its position measurement. This is a longstanding barrier for exploring cavity optomechanics at room temperature. In order to enter the quantum regime of ...

EPFL2022

Synthesis and investigation of the thermal proper- ties of [Co(N H-3)(6)] [Co(C2O4)(3)]center dot 3H(2)O and [Ir(NH3)(6)][Ir(C2O4)(3)]

Ilia Kochetygov

The complexes [Co (NH3)(6)][Ir (C2O4)(3)] and [Ir(NH3)(6)][Co (C2O4)(3)center dot H2O have previously been synthesized and their thermal properties studied. The [Ir(NH3)(6)][Ir(C2O4)(3)] and [Co(NH3)(6)][Co(C2O4)(3)]center dot 3H(2)O complexes considered h ...

INT UNION CRYSTALLOGRAPHY2022

Facet Engineering for Stable, Efficient Perovskite Solar Cells

Michael Graetzel

Facet engineering is an important strategy for tuning the physical, chemical, and electronic properties of a crystal surface, and it also provides an effective route to improve the device performance in many fields. Complex crystal structures with rough mo ...

AMER CHEMICAL SOC2022

Optoelectronics based on the spin-valley physics of 2D materials

Juan Francisco Gonzalez Marin

Two-dimensional (2D) materials are atomically thin crystals with exceptional mechanical, electrical and optical properties. Their unique characteristics originating from quantum confinement in the vertical dimension have attracted a strong interest for sci ...

EPFL2022

Anti-Jahn-Teller effect induced ultrafast insulator to metal transition in perovskite BaBiO3

Changpeng Lin, Ben Xu

The Jahn-Teller (JT) effect involves the ions M with a degenerate electronic state distorting the corner-sharing MO6 octahedra to lift the degeneracy, inducing strong coupling of electrons to lattice, and mediating the exotic properties in perovskite oxide ...

NATURE PORTFOLIO2022

Electrical Spectroscopy of Defect States in Synthetic 2D Materials

Yanfei Zhao

Two-dimensional (2D) materials such as graphene and transition metal dichalcogenide (TMDC) are considered as one of the most promising material platforms for future electronic devices, due to their ultra-thin thickness and fascinating electrical and optica ...

EPFL2022

Room-temperature electrical control of polarization and emission angle in a cavity-integrated 2D pulsed LED

Andras Kis, Dmitrii Unuchek, Juan Francisco Gonzalez Marin, Fedele Tagarelli, Cheol Yeon Cheon, Zhe Sun

Devices based on two-dimensional (2D) semiconductors hold promise for the realization of compact and versatile on-chip interconnects between electrical and optical signals. Although light emitting diodes (LEDs) are fundamental building blocks for integrate ...

Nature Research2022

Single-Mode Emission in InP Microdisks on Si Using Au Antenna

Kirsten Emilie Moselund, Anna Fischer

An important building block for on-chip photonic applications is a scaled emitter. Whispering gallery mode cavities based on III-Vs on Si allow for small device footprints and lasing with low thresholds. However, multimodal emission and wavelength stabilit ...

AMER CHEMICAL SOC2022

Disorder-induced electronic, magnetic, and optoelectronic properties of two-dimensional materials

Cheol Yeon Cheon

Technological advancement has been in cadence with material development by improving the purity of single crystals and, at the same time, controlling their imperfections. These capabilities have been especially vital for developing new technolo-gies based ...

EPFL2022

Crystal-Size-Induced Band Gap Tuning in Perovskite Films

Michael Graetzel, Amita Ummadisingu, Simone Meloni, Wolfgang Richard Tress

A comprehensive picture explaining the effect of the crystal size in metal halide perovskite films on their opto-electronic characteristics is currently lacking. We report that perovskite nanocrystallites exhibit a wider band gap due to concurrent quantum ...

Wiley-VCH Verlag GmbH2021

Novel photoelectric material of perovskite-like (CH3)(3)SPbI3 nanorod arrays with high stability

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Wei Liu, Shanshan Xiao, Ruiyuan Hu

Organometallic halide perovskite materials make great achievements in optoelectronic fields, especially in solar cells, in which the organic cations contain amine components. However, the amine with N-H bonds is easily hydrolyzed with moisture in the air, ...

2021

Ultrafast photo-induced phonon hardening due to Pauli blocking in MAPbI(3) single-crystal and polycrystalline perovskites

Feliciano Giustino, Samuel Poncé

Metal-halide perovskite semiconductors have attracted intense interest over the past decade, particularly for applications in photovoltaics. Low-energy optical phonons combined with significant crystal anharmonicity play an important role in charge-carrier ...

IOP PUBLISHING LTD2021

Mems Shutter Based Variable Optical Attenuator Integrated With Large Core Multimode Rectangular Waveguides

Benedikt Guldimann, Niels Quack, Gergely Huszka, Hamed Sattari, Anton Lagosh

We present the concept and design, and we report on the experimental performance of a broadband Variable Optical Attenuator (VOA) for integration with large-core rectangular multimode waveguides. Operation of an individual 221 mu m x 111 mu m optical waveg ...

IEEE2021

Smart Slit Assembly Employing Continuously Tunable MEMS Shutter

Benedikt Guldimann, Niels Quack, Gergely Huszka, Hamed Sattari, Anton Lagosh

We present the concept and detailed design of a Smart Slit Assembly for next generation spectrometers, and we experimentally demonstrate operation of an individual 221 mu m x 111 mu m smart slit channel employing a MEMS actuated shutter to continuously mod ...

SPIE-INT SOC OPTICAL ENGINEERING2021