Image resolutionImage resolution is the level of detail an holds. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies how close lines can be to each other and still be visibly resolved. Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch), to the overall size of a picture (lines per picture height, also known simply as lines, TV lines, or TVL), or to angular subtense.
Ellipsométrievignette|upright|Ellipsomètre dans un laboratoire du LAAS à Toulouse. vignette|upright|L'ellipsomètre calcule uniquement Psi et Delta, et c'est à partir de cela qu'il réalise ses calculs. L’ellipsométrie est une technique optique de caractérisation et d'analyse de surface, fondée sur le changement d'état de polarisation de la lumière, par réflexion de la lumière sur la surface plane d'un échantillon.
Index-matching materialIn optics, an index-matching material is a substance, usually a liquid, cement (adhesive), or gel, which has an index of refraction that closely approximates that of another object (such as a lens, material, fiber-optic, etc.). When two substances with the same index are in contact, light passes from one to the other with neither reflection nor refraction. As such, they are used for various purposes in science, engineering, and art.
Free-space path lossIn telecommunication, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). The "Standard Definitions of Terms for Antennas", IEEE Std 145-1993, defines free-space loss as "The loss between two isotropic radiators in free space, expressed as a power ratio.
Fixation (histology)In the fields of histology, pathology, and cell biology, fixation is the preservation of biological tissues from decay due to autolysis or putrefaction. It terminates any ongoing biochemical reactions and may also increase the treated tissues' mechanical strength or stability. Tissue fixation is a critical step in the preparation of histological sections, its broad objective being to preserve cells and tissue components and to do this in such a way as to allow for the preparation of thin, stained sections.
Traité de la lumière (Huygens)Dans son Traité de la lumière, écrit à Paris en 1678 mais publié douze ans plus tard lorsqu'il réside aux Pays-Bas, Christian Huygens expose ses conceptions sur la nature de la lumière qui permettent d'expliquer les lois de l'optique géométrique établies par René Descartes. À la différence d'Isaac Newton qui pensait que la lumière était composée de particules émises par la source lumineuse qui venaient frapper l'œil de l'observateur, Huygens conçoit la lumière comme formée d'ondes sphériques qui se propagent dans l'espace à la manière des ondes sonores.
