Accurate determination of the thermal variation of the aperture of step-index optical fibers.
Thermal variations of the aperture of step-index optical fibers have been studied by measuring the transmitted power when a laser beam is launched with a variable incidence. For not too-long fibers only the rays launched with the higher incidence are affected. The variations of their transmittance have been accurately related to the refractive-index ones. Silicone clad silica fibers are sensitive to temperature because the silicone index varies much more the the silica index. On the contrary, due to a compensation phenomenon between index variations of core and cladding materials, PMMA core fibers have apertures that are nearly insensitive to temperature.
Behavior of the refractive index and of the coefficient of thermal expansion of silicone with temperature.
Variation avec la temperature de l'indice de refraction du polydimethylsiloxane utilise pour le revetement des fibres optiques
Commentary: Scholarship as a Way of Life—Character and Virtue in the Age of Big Humanities
From the Renaissance to the nineteenth century, most European scholars considered moral cultivation as the primary purpose of the humanities. The humanities were human not just because they concerned the products of the human mind but also because they transformed scholars and students into better human beings. During the late nineteenth and early twentieth centuries, the rise of Big Humanities questioned this moral purpose. However, Big Humanities also reemphasized the importance of epistemic virtues for scholarship. The language of epistemic virtues helped scholars create new communities of learning and scholarship. Within these communities, the language of virtues established common standards of collaboration and granted scholars a sense of purpose. Many of these scholars also continued to associate epistemic virtues with moral virtues.