Dr. Rémy Claveau Profile

Dr. Rémy Claveau

R&D Engineer at V-Optics SAS

SPIE Involvement:

Author

Publications (8)

Proceedings Article | 16 August 2023 Presentation

Multimodal local spectral/topographic characterization of laser-induced colored stainless steel with coherence scanning interferometry

Paul Montgomery, Sébastien Marbach, Rémy Claveau, Florie Ogor, Christophe Cordier, Jesse Schiffler, Manuel Flury

Proceedings Volume 12618, 126180O (2023) https://doi.org/10.1117/12.2673958

KEYWORDS: Laser interferometry, Stainless steel, Physical coherence, Oxides, Surface roughness, Spectroscopy, Spectral response, Reflectance spectroscopy, Nanosecond lasers, Metals

Read Abstract +

Proceedings Article | 6 October 2021 Presentation + Paper

Histological and cytological imaging using Fourier ptychographic microscopy

Christopher Bendkowski, Bin Fu, Petru Manescu, Rémy Claveau, Delmiro Fernandez-Reyes, Michael Shaw

Proceedings Volume 11879, 1187902 (2021) https://doi.org/10.1117/12.2604455

KEYWORDS: Image restoration, Light emitting diodes, Tissues, Objectives, Imaging systems, Blood, Microscopy, Microscopes, Tissue optics, Image resolution

Read Abstract +

Proceedings Article | 20 June 2021 Presentation

Local spectroscopic characterization of materials using coherence scanning interferometry

Paul Montgomery, Sébastien Marbach, Rémy Claveau, Manuel Flury

Proceedings Volume 11782, 117820S (2021) https://doi.org/10.1117/12.2593011

KEYWORDS: Spectroscopy, Interferometry, Reflectivity, Spectrometers, Calibration, Refractive index, Near field scanning optical microscopy, Near field optics, Microscopy, Microscopes

Read Abstract +

The large spot size of a few mm2 with spectrometers and a few thousand µm2 with ellipsometers means that classical spectroscopic characterization is limited to that of bulk materials. In the development of more recent heterogeneous materials in which there exists local variations between materials on a microscopic scale, a much smaller spot size is required for optical characterization. Several new techniques have been developed for performing local spectroscopy, such as by color camera microscopy, hyperspectral imaging microscopy, scattering type scanning near field optical microscopy (s-SNOM) or spectroscopic optical coherence tomography (s-OCT). Concerning the latter, the related technique of coherence scanning interferometry (CSI) also allows local spectroscopy by applying Fourier Transform processing to the local polychromatic interference fringe signal. This technique offers the advantages of not requiring an external spectrometer since an interferometer is incorporated in the microscope objective, but challenges remain in order to correctly adjust and calibrate the system. In this paper we present some of our latest results of using CSI to accurately measure the local spectra at a microscopic scale with a spot size a little larger than that defined by the diffraction limit, of around 1 µm. Results demonstrate measurements of local reflectance spectra at the surface of a heterogeneous sample and on small structures buried within or under a transparent layer. Other theory has been developed to allow the measurement of local transparent layer thickness and refractive index. As well as performing local point measurements, we show how with a single scan over the optical axis, 2D cartographic maps can be made of reflectance spectra together with the topographic height map of the same area. Any nanometric height errors present due to phase on reflection errors linked to the presence of complex refractive indices can then be corrected using the spectroscopic information.

Proceedings Article | 1 April 2020 Presentation + Paper

White light interference microscopy system design

Sébastien Marbach, Christophe Cordier, Rémy Claveau, Thierry Engel, Paul Montgomery, Manuel Flury

Proceedings Volume 11352, 113521B (2020) https://doi.org/10.1117/12.2555929

KEYWORDS: 3D imaging metrology, Phase interferometry, Mirau interferometers, Optical instrument design, Optical resolution, Interferometry, Interferometers, Objectives, Signal to noise ratio, Imaging systems, Signal processing, Microscopy, Cameras, 3D metrology, Microscopes

Read Abstract +

Proceedings Article | 24 May 2018 Presentation + Paper

Application of coherence scanning interferometry for local spectral characterization of transparent layers

R. Claveau, P. Montgomery, M. Flury

Proceedings Volume 10678, 106780L (2018) https://doi.org/10.1117/12.2314921

KEYWORDS: Reflectivity, Interferometry, Refractive index, Fourier transforms, Signal processing, Thin films, Spatial resolution, Reflectance spectroscopy

Read Abstract +

In the domain of optical metrology, white light interference microscopy is mainly known for performing micro and nano surface profilometry. This is achieved by identifying the envelope peak of the fringe signal. However, the polychromatic signal is rich in information and spectral characterization may be performed through the Fourier analysis of the signal, which gives local spectroscopic information about the sample surface. The use of CSI for studying transparent layers has also been well-developed since the analysis of the reflected light provides both structural and spectral information on the layer. Through the spectral analysis of the reflected light, it has been shown that the morphological properties of a thin film structure, namely the thickness and the refractive index, can be precisely measured. In this case, either the amplitude or the phase of the thin film total reflectance spectrum are used to recover the thickness. The technique is based on the best fit between the experimentally measured spectrum with that of the theoretical model using a non-linear least-squares algorithm. Usually, this spectral method is used to investigate thin films having a thickness that does not exceed a few hundred nanometers. In this work, we apply a similar technique, based on the magnitude of the total reflectance spectrum, to study thicker transparent layers. In this case, we show that precautions regarding the effective numerical aperture of the system need to be considered to obtain consistent values of both the refractive index and the thickness. In addition, we demonstrate the possibility of extracting the depth-resolved reflectance spectra of a buried interface independently from the spectral response of the surface. The consistency of these different spectra is demonstrated by comparing the results with those obtained using a program based on electromagnetic matrix methods for stratified media. The lateral spatial resolution of the measurements attained is a spot size of around 0.84 μm for spectrally characterizing small structures.

Proceedings Article | 26 April 2016 Paper

Local reflectance spectra measurements of surfaces using coherence scanning interferometry

R. Claveau, P. Montgomery, M. Flury, D. Montaner

Proceedings Volume 9890, 98900Q (2016) https://doi.org/10.1117/12.2227625

KEYWORDS: Reflectivity, Spectroscopy, Interferometry, Fourier transforms, Statistical analysis, Microscopes, Cameras, Error analysis, Imaging spectroscopy, Error analysis, Signal processing, Calibration, Objectives

Read Abstract +

Interference microscopy is a widely used technique in optical metrology for the characterization of materials and in particular for measuring the micro and nanotopography of surfaces. Depending on the processing applied to the interference signal, either topographic analysis of the sample can be carried out by identifying the envelope peak of the fringe signal, which leads to 3D surface imaging, or spectral analysis may be performed which gives spectroscopic measurements. By applying a Fourier transform to the interference fringes, information about the source spectrum, the spectral response of the optical system, and the reflectance spectrum of the surface at the origin of the interferogram can be obtained. By using a sample of known reflectivity for calibration, it is possible to extract the spectral signature of the entire system and therefore to deduce that of the surface of interest. In this paper, we first explain theoretically how to retrieve the reflectance information of a surface from the interferometric signal. Then, we present some results obtained by this means with a white light scanning Linnik interferometer on different kinds of samples (silicon, tin oxide (SnO₂), indium tin oxide (ITO)). The initial results were slightly different from those obtained with a conventional optical spectrometer until averaged temporally and were improved even further when averaged spatially. We show that the reflectance of the surface can be calculated over the given wavelength range of the effective spectrum, which is defined as the source spectrum multiplied by the spectral response of the camera and the spectral transmissivity of the optical system. We thus demonstrate that local spectroscopic measurements can be carried out with an interference microscope and that they match well with those measured with an optical spectrometer model Lambda19 UV-VIS-NIR from Perkin Elmer. A simulation study is also presented in order to validate the method and to help identify the potential sources of errors in the spectroscopic analysis.

Proceedings Article | 26 April 2016 Paper

High-resolution full-field optical coherence tomography using high dynamic range image processing

A. Leong-Hoï, R. Claveau, P. Montgomery, B. Serio, W. Uhring, F. Anstotz, M. Flury

Proceedings Volume 9890, 98900E (2016) https://doi.org/10.1117/12.2227114

KEYWORDS: Image resolution, Signal to noise ratio, Image enhancement, Signal processing

Read Abstract +

Proceedings Article | 21 June 2015 Paper

Detection of defects in a transparent polymer with high resolution tomography using white light scanning interferometry and noise reduction

A. Leong-Hoï, R. Claveau, M. Flury, W. Uhring, B. Serio, F. Anstotz, P. Montgomery

Proceedings Volume 9528, 952807 (2015) https://doi.org/10.1117/12.2184559

KEYWORDS: Image processing, Signal to noise ratio, Polymers, Tomography, Denoising, Cameras, Signal processing, Particles, Interferometry, CCD cameras

Read Abstract +

Showing 5 of 8 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years