A5016735601- Adaptive optics and wavefront sensing
- Advanced optical system design
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Optical Coherence Tomography Applications
- Advanced Fiber Laser Technologies
- Corneal surgery and disorders
- Laser-Matter Interactions and Applications
- Solid State Laser Technologies
- Optical Systems and Laser Technology
- Photonic and Optical Devices
- Optical Coatings and Gratings
- Infrared Target Detection Methodologies
- Optical measurement and interference techniques
- Photorefractive and Nonlinear Optics
- Glaucoma and retinal disorders
- Advanced Optical Sensing Technologies
- Semiconductor Lasers and Optical Devices
- Photoacoustic and Ultrasonic Imaging
- Calibration and Measurement Techniques
- CCD and CMOS Imaging Sensors
- Optical Polarization and Ellipsometry
- Advanced Fiber Optic Sensors
- Astronomical Observations and Instrumentation
- Image Processing Techniques and Applications
Université Jean Monnet
2011-2025
Institut d’Optique Graduate School
2014-2025
Université Claude Bernard Lyon 1
2015-2024
Laboratoire Hubert Curien
2015-2024
Centre National de la Recherche Scientifique
2014-2024
Université Paris-Saclay
2021-2024
Laboratoire d’Imagerie Biomédicale
2024
Biologie, ingénierie et imagerie pour l'Ophtalmologie
2022
National Astronomical Research Institute of Thailand
2018
Siddaganga Institute of Technology
2017
We have measured the subpicosecond optical response of a solid-state, semiconductor-to-metal phase transition excited by femtosecond laser pulses. determined dynamic complex refractive index VO2 thin films making pump-probe transmission and reflection measurements at 780 nm. The was found to be largely prompt with properties high-temperature metallic state being attained within 5 ps. ultrafast change in enables switching devices VO2.
Purpose: Fuchs endothelial corneal dystrophy (FEDC) is by far the most common diseases in Western countries, and 50% of keratoplasties are carried out to treat diseases. New treatments also emerging (Descemetorhexis only, rock‐inhibitors, mTor‐inhibitors, FGF‐1). It will therefore soon be vital able determine stage each patient a simple reliable way, order personalize treatment. Visual acuity, retroillumination, specular microscopy thickness mapping 4 pillars examination. However, current...
We have measured the subpicosecond optical response of a solid-state, semiconductor-to-metal phase transition excited by femtosecond laser pulses. determined dynamic complex refractive index polycrystalline VO2 thin-films making pump-probe transmission and reflection measurements at 780 nm. The was found to be largely prompt with properties very close high-temperature metallic state being attained within about 5 ps. equilibration after excitation modeled non-exponentially decaying...
Gabor-domain optical coherence microscopy (GD-OCM) was applied ex vivo in the investigation of corneal cells and their surrounding microstructures with particular attention to endothelium. Experiments using fresh pig eyeballs, excised human buttons from patients Fuchs' endothelial dystrophy (FED), healthy donor corneas were conducted. Results show a large field view (1 mm×1 mm) high definition images different cell types through full thickness at both central peripheral locations porcine...
come from teaching and research institutions in France or abroad, public private centers.L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques niveau recherche, publiés ou non, émanant des établissements d'enseignement recherche français étrangers, laboratoires publics privés. Comparison of the efficiency, MTF chromatic properties four diffractive bifocal intraocular lens designs
We demonstrate the application of a subpicosecond optical parametric amplifier working at degeneracy to imaging in diffuse media. This exhibits small-signal gains greater than 10(4), thereby acting as high-gain ultrafast amplifying gate. have used it construct image grid pattern hidden behind 20 mean free paths highly diffusing solution latex microspheres with spatial resolution 200 microm.
Five search algorithms from the literature of black-box optimization were implemented and applied to optical design problems. These are Particle Swarm Optimization, Gravity Search Algorithm, Cuckoo Search, Covariance Matrix Adaptation Evolution Strategy Nelder&Mead Simplex search. The performance these algorithms' implementations was assessed using BBOB2009 (Black Box Optimization Benchmark) benchmark suite. compared in context two case studies, one with conventional rotationally symmetric...
In this paper we propose contact lens central thickness measurement with a low coherence interferometry technique using either SLED source or broadband continuum generated in air-silica Microstructured Optical Fiber (MOF) pumped picosecond microchip laser.Each of these sources associated the interferometer provides, at same time, good resolution and quick signal recording without moving any optical elements need Fourier Transform operation.Signal improvement is performed afterwards by...
Optimizing freeform systems can encounter convergence difficulties due to the many degrees of freedom that these surfaces bring optical systems. Moreover, description in a polynomial basis may impose prior knowledge on shape surface. In this presentation, we will showcase differential ray tracer with NURBS capabilities called FORMIDABLE. contrast available commercial design software, such as Zemax OpticStudio and Synopsys Code V, library ican simulate especially optimize Non-Uniform Rational...
Lensless color microscopy (also called in-line digital holography) is a recent quantitative 3D imaging method used in several areas including biomedical and microfluidics. By targeting cost-effective compact designs, the wavelength of low-end sources known only imprecisely, particular because their dependence on temperature power supply voltage. This imprecision source biases during reconstruction step. An additional error crosstalk phenomenon, i.e., mixture sensors signals originating from...
The evanescent wave coronagraph (EvWaCo) is a specific kind of band-limited using the frustrated total internal reflection phenomenon to produce coronagraphic effect (removing starlight from image plane in order make stellar environment detectable). In this paper, we present theoretical and experimental study EvWaCo mask. First, calculate transmission show that mask partially achromatic. Then, results obtained unpolarized light at wavelength λ≈900 nm relative spectral bandwidth Δλ/λ≈6%....
The 2.4-m Thai National Telescope (TNT) is the main facility of Observatory located on Doi Inthanon, Thailand's highest mountain. first astronomical images obtained at TNT suffered from diffraction and stray light problems: bright spikes spread stellar over few arcminutes in focal plane, taken during observations moon conditions were contaminated by high levels light. We performed targeted investigations to identify origin these problems. In a time, consisted analyzing irradiance...
In the framework of fusion for energy radiation hard imaging system project, main effects affecting image quality a miniaturized complementary metal-oxide-semiconductor-based camera exposed to doses up 1 MGy(SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) are investigated ITER applications. The related two three subcomponents investigated: optical (OS) and illumination (IS). Subsystem demonstrators have been manufactured selecting...
Purpose: To evaluate the size distribution of epithelial lesions superficial punctate keratitis (SPK) in dry eye after staining ocular surface by sodium fluorescein. Methods: Fluorescein was instilled 10 patients with graded using Oxford Scheme. Pictures were taken a standard Topcon slit lamp cobalt blue light, without barrier filter. Two magnifications (×10 and ×16) used calibrated certified reference grating, allowing diameter observed objects to be determined ImageJ software. The most...
In this Letter we aim to bring an understanding the apparition of multiple spots when using a Shack–Hartmann (SH) wavefront sensor behind diffractive lenses. contrast previous work, phenomenon is described in terms orders. It illustrated with Zemax simulations, where three kinds lenses (monofocal, bifocal, and trifocal) are set microlens array. The presence related phase jump profile also number steps seen through pupil. possibility assessing optical quality such SH measurements discussed,...
In this article, the impact of suppression planar symmetry in three mirror reflective designs is studied through example a reference TMA optimized to be diffraction limited near infrared (NIR) spectrum. This has over YZ plane, and bounded volume one cubic decimeter (volume 1U cubesat) with parabasal ray being normal side cube. A second then derived from no symmetry. still NIR spectrum while having 11% longer focal length for same maximal volume. study manufacturing complexity surfaces show...
To identify the microstructural modification of corneal layers during course disease, optical technologies have been pushing boundary innovation to achieve cellular resolution deep cornea. Gabor-domain coherence microscopy (GD-OCM), an tomography-based technique that can isotropic ∼2-μm over a volume 1 mm × 1.2 mm, was developed investigate modifications in four common diseases. Since individual layer visualization without cutting through several is challenging due curvature, flattening...
The evanescent wave coronagraph uses the principle of frustrated total internal reflection (FTIR) to suppress light coming from star and study its close environment. Its focal plane mask is composed a lens prism placed in contact with each other produce coronagraphic effect. In this paper, we present experimental results obtained using an upgraded Evanescent Wave Coronagraph (EvWaCo). These are also compared theoretical performance through simulations. Experimentally, reach raw contrast...
We report two-dimensional imaging through a liquid scattering medium by noncollinear femtosecond parametric amplification in reflection configuration. The experiment presented permits direct observation at video rate of images with 24‐µm depth resolution and 90‐µm transverse for an area 2.5-mm diameter on the object. These resolutions are achievable turbid phantom near 12 mean free paths double pass.
The first astronomical images obtained at the 2.4 m Thai National Telescope (TNT) during observations in bright moon conditions were contaminated by high levels of light scattered telescope structure. We identified that origins this M3 folding mirror baffle and tube placed inside fork between M4 mirrors. thus decided to design install a new baffle. In step, we calculated optical mechanical inputs needed define design. These were: maximum length baffle, dimensions vanes incident beam diameter...