V. — Qualité des lames et couches réfléchissantes pour le Fabry-Perot - Finesse limite d'un Fabry-Perot formé de lames imparfaites

2014 The defects of the surface of the Fabry-Perot plates significantly change the properties of the etalon ; these can be described by means of a function D(03C3). The ratio of the interval between orders and the width at half height of D(03C3) is called the sharpness limit (ND). With the aid of the coefficient ND it is possible to quickly evaluate the loss in transparency and finesse due to the defects, and one also deduces from it the factor of reflection to be given to the plate coatings. A method for measuring the sharpness limit is given in the article. LE JOURNAL DE PHYSIQUE ET LE RADIUM TOME 19, MARS 1958,