Osteoarthritis involves the progressive degeneration of the cartilage surface, which leads to joint pain and dysfunction. Arthroscopy is the standard procedure for monitoring cartilage degeneration in situ. However, this evaluation depends on the surgeon's subjective interpretation, and therefore may lack reliability. Full-field optical coherence tomography (FFOCT) is a promising technique that could enable micrometer scale cartilage evaluation in situ. A preliminary study was carried out by the Grenoble-Alpes University Hospital in collaboration with TIMC-IMAG laboratory and LLTech to evaluate the ability of the FFOCT microscope commercialized by LLTech to evaluate cartilage quality. FFOCT images were acquired and matching histology sections were prepared for 33 ex vivo cartilage samples. A strong and significant correlation was found between the histology and FFOCT evaluation of the cartilage quality, both qualitatively and quantitatively. In order to use FFOCT for the evaluation of cartilage quality at the micrometer scale in situ, LLTech has developed an endomicroscope version of the FFOCT microscope. When held in contact with the tissue to image, the FFOCT rigid endomicroscope acquires a micron resolution virtual optical slice at a depth of 20 microns below the surface, showing the tissue architecture at this depth in an 'en face' view of 1 mm diameter. This FFOCT endomicroscope has been assessed through images that have been acquired of fresh ex vivo human cartilage samples using both the microscope and endomicroscope. Chondrocytes have been identified in both the microscope and endomicroscope images. Furthermore, a localization environment is under development by the TIMC-IMAG laboratory in order to be able to track the movement of the endomicroscope such that multiple endomicroscope images can be mosaicked together.

In this work, we present methods to control at will the spatio-temporal profile of a transmitted ultrashort pulse at the output of a thick scattering medium. By measuring either the Multispectral [3] or the Time-Resolved Transmission Matrix [4], we can fully describe the propagation of the broadband pulse either in the spectral or in the temporal domain. With a single phase-only SLM, one can manipulate the spatial degrees of freedom to adjust the delay between different optical paths. Therefore, spatial and spectral/temporal distortions of the output light can both be compensated at the same time.

We report the broadband characterization of the propagation of light through a multiple scattering medium by means of its multispectral transmission matrix. Using a single spatial light modulator, our approach enables the full control of both the spatial and spectral properties of an ultrashort pulse transmitted through the medium. We demonstrate spatiotemporal focusing of the pulse at any arbitrary position and time with any desired spectral shape. Our approach opens new perspectives for fundamental studies of light-matter interaction in disordered media, and has potential applications in sensing, coherent control, and imaging.

We report broadband characterization of the propagation of light through a multiply scattering medium by means of its Multi-Spectral Transmission Matrix. Using a single spatial light modulator, our approach enables the full control of both spatial and spectral properties of an ultrashort pulse transmitted through the medium. We demonstrate spatiotemporal focusing of the pulse at any arbitrary position and time with any desired spectral shape. Our approach opens new perspectives for fundamental studies of light-matter interaction in disordered media, and has potential applications in coherent control and imaging.

We present a method to measure the spectrally-resolved transmission matrix of a multiply scattering medium, thus allowing for the deterministic spatiospectral control of a broadband light source by means of wavefront shaping. As a demonstration, we show how the medium can be used to selectively focus one or many spectral components of a femtosecond pulse and how it can be turned into a controllable dispersive optical element to spatially separate different spectral components to arbitrary positions.

La matrice de transmission permet de décrire les effets produit par un milieu multi-diffusant sur une onde monochromatique incidente. L'objectif des travaux présentés dans cette thèse est de développer le concept de matrice de transmission d'un milieu multi-diffusant au cas plus général d'une onde polychromatique impulsionnelle ultra-brève. Dans ce manuscrit nous présentons et mesurons la matrice de transmission multi-spectrale d'un milieu complexe. Cette nouvelle matrice nous donne l'information fondamentale sur le couplage spatio-temporel et spatio-spectral que le milieu engendre au passage d'une onde ultra-brève. Elle permet aussi de contrôler une source monochromatique et polychromatique, après avoir traversé un milieu complexe, de manière déterministe. Nous exploitons ainsi cette connaissance du milieu pour compenser les distorsions du champs en focalisant, façonnant et contrôlant spatialement, spectralement et temporellement un laser ultra-bref grâce à la seule mesure d'une matrice de transmission multi-spectrale. Cette méthode ouvre les portes de plusieurs applications d'imagerie à travers des milieux complexes, ainsi que pour l'interaction lumière-matière en milieux diffusants.

The measurement of the polychromatic transmission matrix of a multiply scattering medium is reported, thus allowing control the propagation of an ultrashort pulse through the medium. We also report on our effort towards fast transmission matrix measurement.

We show that it is possible to initialize and manipulate in a deterministic manner protected qubits using time-varying Hamiltonians. Taking advantage of the symmetries of the system, we predict the effect of the noise during the initialization and manipulation. These predictions are in good agreement with numerical simulations. Our study shows that the topological protection remains efficient under realistic experimental conditions.