Luminous flux amplification in Fabry-Perot spectrometry.

Formulas are derived that enable a comparison, for a given resolution, between the luminosity of a grid Fabry-Perot spectrometer and that of a conventional Fabry-Perot spectrometer.

Influence de la position de l'anneau de phase sur le contraste de l'image dans un objectif à contraste dephase.

The dependence of image contrast on the position of the phase-ring on a phase contrast objective is studied for simple periodic phase objects illuminated by partially coherent light. Graphical relations between the object frequency and the position of the phase-ring for maximum image contrast are provided.