Publications associées à Increasing robustness of bipolar pulse coding in Brillouin distributed fiber sensors

Tunable pump compression and fast modulation for pulsed THz generation

Ileana-Cristina Benea-Chelmus, Shima Rajabali, Yazan Lampert Almahmoud, Alessandro Tomasino

We demonstrate tunable dispersion compensation of femtosecond pulses at telecom wavelengths for broadband Terahertz generation in 7.5-meter fiber link using a Silicon prism pair. The prism pair enhances the amplitude of the THz E-field in InGaAs photocondu ...

IEEE2023

Medipix4, a high granularity four sides buttable pixel readout chip for high resolution spectroscopic X-ray imaging at rates compatible with medical CT scans

Viros Sriskaran

Medipix4 is the latest member in the Medipix/Timepix family of pixel detector chips aimed at high rate spectroscopic X-ray imaging using high-Z materials. The chip address the limitations of conventional hybrid pixel detectors for X-ray imaging. Its predec ...

EPFL2022

Distributed measurement of mode group effective refractive index difference in a few mode optical fibers

Luc Thévenaz, Zhisheng Yang, Alejandro Dominguez Lopez

The possibility to perform distributed measurements of the effective refractive index difference between distinct modes in few mode optical fibers is demonstrated using phase sensitive optical time domain reflectometry. Effective refractive index differenc ...

2022

Pixel super-resolution with spatially entangled photons

Edoardo Charbon, Jiuxuan Zhao

Pixelation is common in quantum imaging systems and limit the image spatial resolution. Here, the authors introduce a pixel super-resolution approach based on measuring the full spatially-resolved joint probability distribution of spatially-entangled photo ...

Nature Portfolio2022

Enhanced Signal-Associated Noise in a φ-OTDR System

Luc Thévenaz, Malak Mohamed Hossameldeen Omar Mohamed Galal, Suneetha Sebastian

Owing to their high sensitivity with respect to external measurands, Rayleigh-based distributed optical fiber sensors (DOFS) find their way into applications in many industrial and academic sectors. To further transcend the limit of these sensors in terms ...

2022

Photonic chip-based resonant supercontinuum via pulse-driven Kerr microresonator solitons

Tobias Kippenberg, Tobias Herr, Junqiu Liu, Miles Henry Anderson, Wenle Weng

Supercontinuum generation and soliton microcomb formation both represent key techniques for the formation of coherent, ultrabroad optical frequency combs, enabling the RF-to-optical link. Coherent supercontinuum generation typically relies on ultrashort pu ...

2021

Time-Varying Components for Enhancing Wireless Transfer of Power and Information

Romain Christophe Rémy Fleury, Mohammad Sajjad Mirmoosa, Xuchen Wang

Temporal modulation of components of electromagnetic systems provides an exceptional opportunity to engineer the response of those systems in a desired fashion, both in the time and frequency domains. For engineering time-modulated systems, one needs to th ...

American Physical Society (APS)2021

Direct time-of-flight SPAD image sensors for light detection and ranging

Preethi Padmanabhan

Depth sensing is an increasingly important feature in many applications of consumer, automotive, augmented/virtual reality (AR-VR), space and bio-medical imaging. Long range, high depth resolution, high spatial resolution, and high frame rates are often co ...

EPFL2021

Gain-switched semiconductor laser driven soliton microcombs

Tobias Kippenberg, Erwan Guillaume Albert Lucas, Junqiu Liu, Wenle Weng, Jijun He

Dissipative Kerr soliton generation using self-injection-locked III-V lasers has enabled fully integrated hybrid microcombs that operate in turnkey mode and can access microwave repetition rates. Yet, continuous-wave-driven soliton microcombs exhibit low e ...

Nature Research2021

Distributed and dynamic strain sensing with high spatial resolution and large measurable strain range

Luc Thévenaz, Zhisheng Yang, Li Zhang, Malak Mohamed Hossameldeen Omar Mohamed Galal

A distributed and dynamic strain sensing system based on frequency-scanning phase-sensitive optical time domain reflectometry is proposed and demonstrated. By utilizing an RF pulse scheme with a fast arbitrary waveform generator, a train of optical pulses ...

2020

Short spatial resolutions retrieval from a long pulse BOTDA trace

Luc Thévenaz, Simon Adrien Zaslawski, Zhisheng Yang, Sheng Wang

A novel, to the best of our knowledge, postprocessing technique is proposed to extract with a flexible and variable spatial resolution the information from Brillouin optical time-domain analyzers, obtained using a pulse longer than the acoustic settling ti ...

2020

Comprehensive Spectral Analysis of PWM Waveforms With Compensated DC link Oscillations

Drazen Dujic, Stefan Milovanovic

In the available literature, including reference books on the topic, the spectral analysis of voltage waveforms obtained through the use of pulse-width modulation relies on the assumption of an ideally flat voltage across the DC link of a considered switch ...

2020

Demonstration of Tunable Optical Aggregation of QPSK to 16-QAM Over Optically Generated Nyquist Pulse Trains Using Nonlinear Wave Mixing and a Kerr Frequency Comb

Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Fatemeh Alishahi, Arne Kordts, Maxim Karpov, Ahmad Fallahpour, Cong Liu

A tunable and reconfigurable optical aggregation system is experimentally demonstrated. Optical Nyquist pulses are generated on multiple channels using a microresonator-based Kerr optical frequency comb and insertion of uniform lines by an intensity modula ...

IEEE Institute of Electrical and Electronics Engineers2020

Performance analysis of the differential pulse-width pair Brillouin optical time domain analysis using the log normalized and linearly normalized gain

Luc Thévenaz, Simon Adrien Zaslawski, Zhisheng Yang

The performance of the differential pulse-width pair Brillouin optical time domain analysis (DPP-BOTDA) is evaluated experimentally using either the gain from log normalization or linear normalization for the subtraction of traces collected with pump pulse ...

SPIE2019

High spatial resolution and intrinsically strain-insensitive distributed temperature sensing based on stimulated Brillouin scattering in gas

Luc Thévenaz, Flavien Gyger

Temperature/strain cross sensitivity is a long-standing issue in Brillouin-based distributed sensors, impairing the reliability of such sensors. So far, all the proposed methods perform the discrimination by measuring two quantities showing distinct respon ...

SPIE2019

Transverse Detection of DNA Using a MoS2 Nanopore

Aleksandra Radenovic, Michael Graf, Martina Lihter, Sanjin Marion

Classical nanopore sensing relies on the measurement of the ion current passing through a nanopore. Whenever a molecule electrophoretically translocates through the narrow constriction, it modulates the ion current. Although this approach allows one to mea ...

2019

Optimizing Image Denoising for Long-Range Brillouin Distributed Fiber Sensing

Luc Thévenaz, Marcelo Alfonso Soto Hernandez

Linear and nonlinear two-dimensional image processing approaches are analyzed with the aim of removing noise from data acquired by distributed optical fiber sensors based on Brillouin optical time-domain analysis (BOTDA). The impact of the filter parameter ...

IEEE Institute of Electrical and Electronics Engineers2018

Design Techniques for High-Speed Multi-Level Viterbi Detectors and Trellis-Coded-Modulation Decoders

Andreas Peter Burg, Lukas Kull, Thomas Toifl, Giovanni Cherubini

The implementation of a 25.6-Gb/s four-level pulse-amplitude-modulation (4-PAM) reduced-state sliding-block Viterbi detector (VD) is presented. The power consumption of the VD is 105 orilV at a supply voltage of 0.7 V, corresponding to an energy efficiency ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2018

Analytical expression and experimental validation of the Brillouin gain spectral broadening at any sensing spatial resolution

Luc Thévenaz, Mohammad Mehdi Alem Karladani, Marcelo Alfonso Soto Hernandez

A novel and simple analytical expression to describe the Brillouin gain spectral broadening as a function of the spatial resolution in time-domain Brillouin distributed fiber sensors is deduced. The proposed model is experimentally validated using a pump-p ...

Ieee2017

Determination of the radiance of cylindrical light diffusers: design of a one-axis charge-coupled device camera-based goniometer setup

Georges Wagnières, Matthieu Philippe Emmanuel Zellweger, Blaise Lovisa, Andreas Pitzschke, Jenny Bertholet

A one-axis charge-coupled device camera-based goniometer setup was developed to measure the three-dimensional radiance profile ( longitudinal, azimuthal, and polar) of cylindrical light diffusers in air and water. An algorithm was programmed to project the ...

SPIE Society of Photo-optical Instrumentation Engineers2017