Publications associées à Minimizing distortion and enlarging group delay in Brillouin slow light systems by gain profile optimization

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

Cavitation induced by pulsed and continuous-wave fiber lasers in confinement

Christophe Moser, Jan Krizek

Bubbles generated with lasers in liquids under confinement have been investigated for their potential use as the driving mechanism for liquid micro-jets in various microfluidic devices, such as needle-free jet injectors. Here, we report on the study of bub ...

ELSEVIER SCIENCE INC2023

Evaluating the effect of sparse convolutions on point cloud compression

Touradj Ebrahimi, Davi Nachtigall Lazzarotto

The use of point clouds as an imaging modality has been rapidly growing, motivating research on compression methods to enable efficient transmission and storage for many applications. While compression standards relying on conven- tional techniques such as ...

2023

Exploring nonlinearities in multimode optical fibers for lasers and computing

Ugur Tegin

Multimode optical fibers are the backbone of telecommunication and medical imaging. When light with high intensity travels through a multimode fiber, photons and matter start to interact and propa-gation becomes nonlinear. The nonlinear propagation of ligh ...

EPFL2021

Study on the signal-to-noise ratio of Brillouin optical-time domain analyzers

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Zhisheng Yang, Sheng Wang

The signal-to-noise ratio (SNR) of Brillouin optical time-domain analyzers (BOTDA) is modelled and experimentally validated, using direct detection with and without the use of optical pre-amplification. The behavior of SNR as a function of the Brillouin ga ...

2020

Controlling spatiotemporal nonlinearities in multimode fibers with deep neural networks

Navid Borhani, Demetri Psaltis, Christophe Moser, Babak Rahmani, Eirini Kakkava, Ugur Tegin

Spatiotemporal nonlinear interactions in multimode fibers are of interest for beam shaping and frequency conversion by exploiting the nonlinear interaction of different pump modes from quasi-continuous wave to ultrashort pulses centered around visible to i ...

2020

System and method for a retinal projector based on a scattering reflector

Demetri Psaltis, Christophe Moser

A retinal projector system, comprising a coupling means, a spacial light modulator, and a tapered optical waveguide having an input side surface and an output side surface, whereby the input side surface is larger than the output side surface, the coupling ...

2020

Development of coherent mid-infrared source using chalcogenide photonic crystal fibers

Sida Xing

Many molecule bonds have vibration frequencies in the mid-infrared band. Thus, this band is of great interest to molecular spectroscopy, material processing and medical applications. However, many optical materials typically used for laser sources experien ...

EPFL2019

Local activation of surface and hybrid acoustic waves in optical microwires

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Desmond Chow Ming Chia

Elastic vibrations in subwavelength structures have gained importance recently in fundamental light–matter studies and various optoacoustic applications. Existing techniques have revealed the presence of distinct acoustic resonances inside silica microwire ...

2018

Mask-aligner Talbot lithography using a 193 nm CW light source

Wilfried Noell, Toralf Scharf, Raoul Kirner, Andreas Vetter

We present and discuss Talbot mask-aligner lithography, relying on a continuous wave laser emitting at 193nm for the illumination. In this source, a diode laser at 772nm is amplified by a tapered amplifier in master-oscillator power-amplifier configuration ...

2018

Erbium doped random fiber laser and fiber mixing effect

Luc Thévenaz, Camille Sophie Brès, Can Yao

We demonstrate an active random fiber laser by directly pumping a 100 m erbium-doped fiber at 980 nm wavelength, with a fiber loop mirror forming a half-open cavity. Random lasing with competing spectral modes in the range from 1535 nm to 1560 nm is achiev ...

2017

Control of pulsed light propagation through multimode optical fibers

Edgar Emilio Morales Delgado

Visualization of organs and cells in the interior of living beings is a challenging task due to the light absorption and multiple light scattering occurring in biological tissue that prevents the di-rect transmission of images. A standard visualization app ...

EPFL2017

Multimode fiber optical imaging using wavefront control

Nicolino Stasio

Optical microscopy enables us to observe at high resolution and with a large field of view objects otherwise invisible for the naked eye. This is why it is becoming a fundamental tool in biology and in diagnostics, where observation at cellular level can t ...

EPFL2017

Microscopy and digital light shaping through optical fibers

Damien Claude-Marie Loterie

Microscopy is an essential tool in medicine and biomedical research. Traditional microscopes rely on bulky optics, complicating their usage when studying live animal tissues. In addition, light cannot penetrate very far in most biological tissues due to sc ...

EPFL2017

Aberrations of the point spread function of a multimode fiber due to partial mode excitation

Adrien Charles-François Raymond Descloux

We investigate the point spread function of a multimode fiber. The distortion of the focal spot created on the fiber output facet is studied for a variety of the parameters. We develop a theoretical model of wavefront shaping through a multimode fiber and ...

Optical Society of America2016

Characterization and modeling of microstructured chalcogenide fibers for efficient mid-infrared wavelength conversion

Camille Sophie Brès, Adrien Billat, Svyatoslav Kharitonov, Davide Grassani, Sida Xing

We experimentally demonstrate wavelength conversion in the 2 μm region by four-wave mixing in an AsSe and a GeAsSe chalcogenide photonic crystal fibers. A maximum conversion efficiency of −25.4 dB is measured for 112 mW of coupled continuous wave pump in a ...

Optical Society of America2016

Optimized Packet Scheduling in Multiview Video Navigation Systems

Pascal Frossard, Thomas Maugey, Laura Toni

In multiview video systems, multiple cameras generally acquire the same scene from different perspectives, such that users have the possibility to select their preferred viewpoint. This results in large amounts of highly redundant data, which needs to be p ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Dual-pump sweep-free stimulated Brillouin optical distributed sensing method and device

Luc Thévenaz, Sang Hoon Chin

The present invention concerns a Brillouin optical distributed sensing method, comprising steps of: (i) providing a first and a second optical pulsed pump wave (20, 23) and an optical probe wave comprising at least one probe spectral component (26), (ii) d ...

World Intellectual Property Organization2014

Dynamic control of light transmission through multimode fibers

Ioannis Papadopoulos

In the present thesis we demonstrate how under the appropriate dynamic control of light propagation, multimode fibers can be transformed into deterministic optical elements that along with their ultrathin size, large number of degrees of freedom and high N ...

EPFL2014

Extending the Real Remoteness of Long-Range Brillouin Optical Time-Domain Fiber Analyzers

Luc Thévenaz, Sang Hoon Chin, Marcelo Alfonso Soto Hernandez

The real remoteness of a distributed optical fiber sensor based on Brillouin optical time-domain analysis is considerably extended in this paper using seeded second-order Raman amplification and optical pulse coding. The presented analysis and the experime ...

IEEE Institute of Electrical and Electronics Engineers2014