A5019383305- Terahertz technology and applications
- Photonic and Optical Devices
- Superconducting and THz Device Technology
- Spectroscopy and Laser Applications
- Near-Field Optical Microscopy
- Photonic Crystals and Applications
- Advanced X-ray Imaging Techniques
- Thermography and Photoacoustic Techniques
- Acoustic Wave Resonator Technologies
- Gyrotron and Vacuum Electronics Research
- Semiconductor Quantum Structures and Devices
- Microwave Engineering and Waveguides
- Digital Holography and Microscopy
- Advanced Fiber Laser Technologies
- Microwave and Dielectric Measurement Techniques
- Advanced Chemical Sensor Technologies
- Laser-Matter Interactions and Applications
- Advanced Antenna and Metasurface Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Prostate Cancer Treatment and Research
- Photonic Crystal and Fiber Optics
- Optical Coatings and Gratings
- Plant and animal studies
- Infrared Thermography in Medicine
- Millimeter-Wave Propagation and Modeling
Institut Polytechnique de Bordeaux
2016-2025
Université de Bordeaux
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Laboratoire de l'Intégration du Matériau au Système
2016-2025
Saratov State University
2019
Institute of Precision Mechanics and Control
2019
The University of Tokyo
2018
Kyoto University
2018
Nagoya University
2018
Tohoku University
2018
Standard optical lithography relying on clean room and microelectronic facilities is used to fabricate a thin-flexible metamaterial absorber, designed operate at submillimeter wavelengths over the 0.1-1 THz frequency band. Large terahertz absorption has been demonstrated numerically through experimental measurements with maximum level of about 80%. We put emphasis in this present work use single-sized "meta-cells" achieve multiple peaks. Furthermore, dielectric spacer makes it promising for...
The usability of pulsed broadband terahertz radiation for the inspection composite materials from aeronautics industry is investigated, with goal developing a mobile time-domain spectroscopy system that operates in reflection geometry. A wide range samples based on glass and carbon fiber reinforced plastics various types defects examined using an imaging system; results are evaluated both time frequency domain. conductivity fibers prevents penetration respective but also allows analysis...
In this paper, a model of the beam propagation is developed according to physical properties THz waves used in computed tomography (CT) scan imaging.This first included an acquisition simulator observe and estimate impact Gaussian intensity profile on projection sets.Second, introduced several inversion methods as convolution filter perform efficient tomographic reconstructions simulated real acquired objects.Results obtained with three reconstruction (BFP, SART OSEM) are compared techniques...
Additive manufacturing (AM) technology is not only used to make 3D objects but also for rapid prototyping. In industry and laboratories, quality controls these are necessary though difficult implement compared classical methods of fabrication because the layer-by-layer printing allows very complex object that unachievable with standard tools. Furthermore, AM can induce unknown or unexpected defects. Consequently, we demonstrate terahertz (THz) imaging as an innovative method 2D inspection...
The failure to accurately define tumor margins during breast conserving surgery (BCS) results in a 20% re-excision rate. present paper reports the investigation evaluate potential of terahertz imaging for tissue recognition within under-explored 300 - 600 GHz range. Such frequency window matches new BiCMOS technology capabilities and thus opens up opportunity near-field using these devices. To assess efficacy this band, data from 16 freshly excised samples were collected analyzed directly...
Reflection terahertz frequency modulated continuous waves scanner (300 GHz) has been proficiently optimized for imaging two easel paintings of different age. The information content the obtained THz images fully inspected by selecting appropriate image parameter. At same time, a new data processing developed improving level detail held axial parametric means Gaussian fit reflected signals. By carefully weighting signals as function optical path, amplitude corrected positioning object surface...
In this paper, we present an advanced image processing sequence to perform nondestructive inspection from 3-D terahertz (THz) images. We develop all the steps starting a tomographic reconstruction of sample radiographs acquired with monochromatic millimeter-wave imaging system automated segmentation, extracting different volumes interest (VOI) composing sample. This leads visualization and dimensional measurements. is completed by skeletonization caliber analysis providing accurate...
Thanks to significant advances in real-time terahertz imaging terms of resolution and image quality, adapting extending optical methods for 3D at the millimeter scale is now promising. The shape-from-focus algorithm a post-processing tool used microscopy reconstruct external shape surface convex object. Images acquired different distances from object-side focal plane are implemented this algorithm. We localize best focus position stack images each pixel then object due short depth field. In...
Abstract Imaging with terahertz (THz) waves has been expected as a non-invasive/non-staining visualization tool for breast cancer margins during surgeries. Breast is generic name heterogeneous lesion comprising invasive adenocarcinoma, in situ most frequently the form of ductal carcinoma (DCIS) and benign tissues. Until now, THz imaging focused on adenocarcinoma; however, analysis DCIS hardly performed. One reasons that size an individual lesion, ranging from 50 to 500 µ m, typically much...
Abstract This paper reports investigations led on the combination of refractive index and morphological dilation to enhance performances towards breast tumour margin delineation during conserving surgeries. The map invasive ductal lobular carcinomas were constructed from an inverse electromagnetic problem. Morphological combined with thresholding was conducted classify tissue regions as malignant or benign. A histology routine evaluate various geometries associated different thresholds. It...
Terahertz spectroscopy, a noninvasive and nondestructive analytical technique used in art conservation restoration, can provide compelling data concerning the composition condition of culturally valuable historical objects. spectral databases modern ancient artists' pigments exist but lack explanations for origins unique features. Solid-state density functional theory simulations insight into molecular intermolecular forces that dominate observed absorption features as well reveal deviations...
We developed a scanning laser terahertz (THz) near-field reflection imaging system using fiber-coupled femtosecond source for high spatial resolution measurements without any sub-wavelength probes. In this system, THz wave pulses generated at the focusing spot in non-linear optical crystal interact with sample set on crystal. Using we obtained images of metallic structures ∼λTHz/34 (λTHz = 680 μm) and also observed paraffin-embedded human breast tissue several 10 μm size. These results...
Terahertz phase retrieval is a promising technique able to assess the complex diffracted wave properties through an iterative processing algorithm. In this Letter, we demonstrate implementation of in reflection geometry with continuous acquisition system working at 0.287 THz. To ensure high signal-to-noise ratio measured dataset, proposed double parallel recording scheme one detector and two lock-in amplifiers operating complimentary sensitivity setting. This provided higher numerical...
We investigate in this paper a new reconstruction method order to perform 3D Terahertz (THz) tomography using continuous wave acquisition setup transmission mode.This is based on the Maximum Likelihood for TRansmission (ML-TR) first developed X-ray imaging.We optimize Ordered Subsets Convex (OSC) implementation of ML-TR by including Gaussian propagation model THz waves and take into account intensity distributions both blank calibration scan dark-field measured detectors.THz quality accuracy...
Terahertz waves cover photon energies that are orders of magnitude smaller (0.4-40 meV) than the visual spectrum. Therefore, they provide additional information on intrinsic condensed-matter properties, making them attractive for imaging applications in life sciences [1], [2]. Furthermore, do not have an ionizing effect and considered biologically innocuous. The ever-present water organic matter strongly absorbs terahertz waves, subtle changes concentration can be indicative disease [3]....
This paper presents the development, performance, integration, and implementation of a 150 GHz FMCW radar based on homodyne harmonic mixing scheme for noncontact, nondestructive testing. system offers high-dynamic-range measurement capabilities up to 100 dB rates 7.62 kHz. Such interesting characteristics make this attractive imaging applications or contactless sensing. Numerous samples different materials geometries were imaged by taking advantage radar's performance. By into account...
This paper addresses a passive system capable of converting linearly polarized THz beam into radially one. is obtained by extending to frequencies and waveguides an already proven concept based on mode selection in optical fibers. The approach validated at 0.1 owing the realization prototype involving circular waveguide two tapers that exhibits its output. By simple homothetic size reduction, can be easily adapted higher frequencies.