JP

An algorithm of unordered wavefront propagation in terahertz phase retrieval with dense multiplane data acquisition

by
Research figure associated with An algorithm of unordered wavefront propagation in terahertz phase retrieval with dense multiplane data acquisition

An in-depth editorial guide to An algorithm of unordered wavefront propagation in terahertz phase retrieval with dense multiplane data acquisition, its scientific context, terahertz contribution, applications, and collaboration potential in Biomedical Imaging.

Durabilité des ressources pédagogiques sur support mobile en génie électrique

by
Research figure associated with Durabilité des ressources pédagogiques sur support mobile en génie électrique

An in-depth editorial guide to Durabilité des ressources pédagogiques sur support mobile en génie électrique, its scientific context, terahertz contribution, applications, and collaboration potential in Non-Destructive Testing.

SubTHz Fully-Metallic Geodesic Luneburg Lens Antenna

by
Research figure associated with SubTHz Fully-Metallic Geodesic Luneburg Lens Antenna

Executive Summary A team of researchers from KTH Royal Institute of Technology, INSA Rennes, the University of Bordeaux, and ESA has developed and experimentally validated a fully metallic geodesic Luneburg lens antenna that operates in the sub‑terahertz (sub‑THz) frequency band between 128 and 132…

Terahertz Geodesic Luneburg Lens Antenna

by
Terahertz Luneberg Lens

Pushing Sub-THz Frontiers: Our Fully-Metallic Geodesic Luneburg Lens Antenna Why Sub-THz Luneberg lens Matters Classical Luneburg lenses have too much losses above 80 GHz. Together and colleagues at KTH Stockholm, ESA Noordwijk and IETR Rennes, we decided to tackle those issues head-on with a radically different solution—one that would rely on purely metallic wave-guiding optics … Read more

Skeletonization and 3D rendering with real time terahertz tomography

by

In this collaborative article between Lytid, IMS and Noctylio, we explore the application of terahertz (THz) technology in tomography to create 3D reconstructions in real time. The experimental setup is based on a latest generation micro-bolometric camera with 240×320 pixels, equipped with an anti-reflective coated lens developed by Lytid, to record the projection images of … Read more

Feasibility of Using a 300 GHz Radar to Detect Fractures and Lithological Changes in Rocks

by
FMCW radar rock non destructive testing

This article examines the possibility of using a high frequency radar (300 GHz) to detect fractures and lithological changes in rocks. This study, carried out in collaboration between Federico Sanjuan (University of Pau, France) and the IMS laboratory (University of Bordeaux), is in the context of the improvement of the methods of detection and quantification … Read more

Terahertz diffractive imaging with saturated data inpainting

by

This article focuses on improving diffraction imaging techniques in the field of Térahertz frequencies, by approaching the problem of data saturation due to the limited dynamic range of detection systems. We introduce with the ITMO team (Nikolay V Petrov Team) a new approach to algorithmic reconstruction which deals with saturated areas in the measured intensity … Read more

HOBIT-a New Concept for Pedagogical Innovations in Learning and Teaching Optics

by

Presentations of the latest HOBIT developments Martin Hachet (INRIA) presented in Jul 2021 the last HOBIT developments at the 13th annual International Conference on Education and New Learning Technologies in Spain (Virtual). You can watch the recorded presentation from the HAL open archive. More details about this publication https://hal.inria.fr/hal-03251807/ Hachet, M., Canioni, L., Guillet, J. … Read more

Varnish Ageing characterization with terahertz waves

by

This paper focuses on the analysis of time-domain data regarding the measurements conducted on a French Renaissance painting realized on a metal substrate (copper). We specifically focus on the dielectric characterization of the varnish layer and its ageing consequences on THz images. Principal investigators are Quentin Cassar and Corinna Koch Dandolo. The painting The oil … Read more

Teragogic

by

Terahertz open source scanner Terahertz and millimeter waves technologies have followed to a decade of strong development, thanks to leading promising applications fields such as hyper-spectral imaging, non-destructive testing and spectroscopy. However, the generally high cost of such systems limits their use to academic research laboratories or high added value industries. With Teragogic project, we … Read more

Guided Reflectometry Imaging Unit using Millimeter Wave FMCW Radars

by
Plastic wavguide for terahertz sensing in reflection

In this paper published in july 2020 in IEEE Transactions on Terahertz Science and Technology, we present a reflectometry sensing system associated with a frequency modulated continuous wave radar. Then, a solid immersion lens is added to the system to improve the resolution. Abstract of terahertz reflectometry setup Frequency Modulated Continuous Wave (FMCW) radar systems … Read more

Terahertz Phase Retrieval Imaging in Reflection

by
Terahertz holography in relfection

Collaboration with ITMO University about Terahertz After the visit of the great museum of optics in ITMO, Saint Petersbourg, Russia, an interesting discussion started with ITMO colleagues about terahertz phase retrieval and holography. We were also pleased to invite Nicholay Petrov at IMS Laboratory in Bordeaux. I am delighted to present here the results of … Read more

Guided terahertz pulse reflectometry with double photoconductive antenna

by
Guided Terahertz reflectometry setup

This article presents a terahertz imaging system using a waveguide with a reflection topology. The system is based on a femtosecond pulse laser, a transceiver, and a silica pipe hollow-core waveguide. Silicon lens, beam splitter or coupler is no more required to manipulate the terahertz beam in free space, which makes this system setup more … Read more

Article about Terahertz in Les Echos

by

Les Echos, the french leading business daily publish today an article about the applications of Terahertz Waves in radio astronomy, scientific instrumentation, medical diagnostic, high-speed data communication, security, non-destructive quality control in industrial production and pharmacology. Several French researchers were interviewed and you will notably be able to find the results of work carried out … Read more

Paris Air Show 2019

by

As part of the Saphyr project, photonic and aeronautic prototypes from the Aquitaine region will be presented at the Paris Air show 2019. Visit our booth A120 Hall 4 to discuss terahertz waves applied to non-destructive testing. This project is in collaboration between the IMS laboratory (Laser & Terahertz Test Team) and R&D Vision.

Is terahertz radiation dangerous? Effects of terahertz radiation.

by
Terahertz wave safety and protection

Regulation limits from microwaves and infrared The terahertz region is between the radio frequency region and infrared. Both the IEEE RF safety standard [1] and the ANSI Laser safety standard [2] have limits into the terahertz region, but both safety limits are based on extrapolations. The ICNIRP recommends that between 10 GHz and 300 GHz, the power … Read more

What is Smartphonics

by
Learn using a Smartphone

Origin of this word Smartphonics Smartphones have become ubiquitous objects in the daily lives of students. Rather than using them for entertainment, why not take advantage of this object to impart knowledge, experiment and teach? We use the word Smartpnonics in the context of using the smartphone for education, and not as a smartphone study … Read more

NearSense – Advances Towards a Silicon-Based Terahertz Near-Field Imaging Sensor for Ex Vivo Breast Tumour Identification

by

This paper present the terahertz near field resonator developed in the framework of Nearsense project and pulse time domain images used to determine the best frequency and design the resonator. Mavarani, L., Hillger, P., Bücher, T., Grzyb, J., Pfeiffer, U. R., Cassar, Q., … & MacGrogan, G. (2018). NearSense–Advances Towards a Silicon-Based Terahertz Near-Field Imaging … Read more

A Solid-State 0.56 THz Near-Field Array for μM-Scale Surface Imaging

by

We This paper presents a fully-integrated 0.56 THz 128-pixel near-field 1-D sensor array with 10-12 μm lateral resolution. The sensing elements are based two parallel cross-bridged split-ring resonators that utilize a 3-D topology to exhibit high field confinement in the sensing spot. The sensor comprises a scalable excitation scheme that is designed to maximize the … Read more

Study of blood plasma optical properties in mice grafted with Ehrlich carcinoma in the frequency range 0.1 – 1.0 THz

by

In the course of in vitro studies of blood of laboratory animals with progressing Ehrlich carcinoma, we have revealed the change of the blood plasma optical properties in the THz range, which can be used for developing the express diagnostics of the presence of oncological diseases. An applied software package is elaborated that allows the … Read more

Terahertz biophotonics as a tool for studies of dielectric and spectral properties of biological tissues and liquids

by

In this review, we describe dielectric properties of biological tissues and liquids in the context of terahertz (THz) biophotonics. We discuss a model of the THz dielectric permittivity of water and water-containing media, which yields analysis of the relaxation and damped resonant molecules modes. We briefly describe modern techniques of THz spectroscopy and imaging employed in biophotonics with a strong emphasize on a … Read more

Terahertz frequency modulated continuous wave imaging advanced data processing for art painting analysis

by

In this paper, we focus on data processing applied to terahertz FMCW measurement of a painting. Investigated paintings FMCW radar processing The proposed approach consist to use longitudinal information of FMCW signal to adjust amplitude. This calibration process was tested on a stepped target and then on the investigated painting, giving a more homogeneous result, … Read more

What is terahertz?

by
Frequency from 100 GHz to 10 THz, wavelenght from 3mm to 30µm , crosses most dielectrics, absorbed by water, total reflection on metal and non ionising

Terahertz frequency band Terahertz (THz) waves is a part of the electromagnetic spectrum between infrared and microwave radiation corresponding to wavelenghts from 3 mm to 100 µm. In the frequency domain, it consists of the band from 100 GHz to 30 THz (See Fig 1.). For 1 Thz, wavelenght is about 300 µm, photo energy … Read more

Terahertz Spectroscopy and Quantum Mechanical Simulations of Crystalline Copper-Containing Historical Pigments

by

Terahertz spectroscopy is a non-destructive analytical technique used in art conservation and restoration. It can provide compelling data concerning the composition and condition of culturally valuable and historical objects. Terahertz spectral databases of modern and ancient artists’ pigments exist, but lack explanations for the origins of the unique spectral features. This paper present terahertz spectra … Read more

Jean-Paul Guillet

by

Welcome to my personal website! It presents my research activities at IMS laboratory in Bordeaux University and teaching at Bordeaux University Institute of Technology. You can find my list of publications or list of topics. To learn more about my research activities at IMS Laboratory, you can visit the Laser & terahertz test team website … Read more

Processing sequence for non-destructive inspection based on 3D terahertz images

by

In this paper, a processing sequence has been developed to achieve automated analysis and measurements from 3D terahertz acquisitions. This sequence first performs a tomographic reconstruction from a 3D acquisition made by a continuous millimetre wave system. This reconstruction is based on the Ordered Subsets Convex (OSC) algorithm and has been optimized for 3D THz tomography. Optimisations consist of i) including the Gaussian beam model in the computation of expected measured intensity, ii) modelling the blank scan and dark-field from measurements and, iii) taking account for these models in the algorithm. The new method, called THz-OSC, outperforms both the BFP and THz-SART reconstructions.

Read more

Terahertz radiation for tomographic inspection

by

This paper demonstrate how it is possible to take into account the physical properties of THz waves used in THz CT scan imaging as an improved beam propagation model. This more realistic model is clearly justified by the fact that previous models were simply relying on well-known and commonly applied X-ray reconstruction methods, which assume a ray tracing approach, whereas the THz beam profile is very far from this hypothesis. The model is introduced in several inversion methods as a convolution filter to perform efficient tomographic reconstructions of acquired objects.

Read more

Near-field wire-based passive probe antenna for the selective detection of the longitudinal electric field at terahertz frequencies

by

Adam, R., Chusseau, L., Grosjean, T., Penarier, A., Guillet, J. P., & Charraut, D. (2009). Near-field wire-based passive probe antenna for the selective detection of the longitudinal electric field at terahertz frequencies. Journal of Applied Physics, 106(7), 073107.

Read more

Biography

by
Jean-Paul Guillet Biography

Jean-Paul Guillet was born in Lyon, France in 1984. He is graduated from Montpellier University. He received the M.Sc and Ph.D degres in 2007 and 2010 in terahertz imaging from IES lab, Montpellier, France. The topic of this first research work was terahertz near field microscopy using electronics based components. During postdoc up to 2013, … Read more

Scientific networks

by

You can follow me via these networks: Scientific online networks and search engines Google Scholar Scientific journal search engine Google scholar is the best scientific search engine. You can use it to display all you paper. My Google Scholar page is https://scholar.google.fr/citations?user=Te3MRH8AAAAJ&hl=fr Researchgate The main research network ResearchGate is a free social network service for … Read more

BIS : Bordeaux International Service

by

Interview about Bordeaux International Support in the framework of HUST collaboration : http://www.u-bordeaux.fr/Actualites/De-l-international/BIS-Jean-Paul-Guillet-temoigne

Colloque GEII Bordeaux 2015

by

We organized the annual educational seminar which brings together Electronics Engineering technological University departments throughout France in Bordeaux in 2015.

Read more

Art Painting Diagnostic Before Restoration with Terahertz and Millimeter Waves

by

Introduction Terahertz time domain imaging, FMCW and spectroscopy are useful tools for art restorer to inspect paintings and other cultural. Thanks to the different terahertz equipments present on the terahertz platform in Bordeaux, we have set up collaborations with art restorers and researchers working on the analysis of works of art with terahertz. This article presents … Read more

Karnaugh map

by

Karnaugh map is a graphic method allowing to find the logical equation from a truth table. This free educative android application shows graphically the resolution of Karnaugh map. Download Karnaugh Map (free Android application) in Google Play Store

Coupling and propagation of Sommerfeld waves at 100 and 300 GHz

by

The coupling between a linearly-polarized gaussian beam and a Sommerfeld wave propagating on a circular metallic wire is obtained owing to a differential phase element inserted in front of the metal wire. At millimeter-wavelengths we calculate a theoretical maximum coupling efficiency of 32% for this system in spite of the metal nature and radius in … Read more