NUMERICAL DETERMINATION OF THE FACTOR OF ENCIRCLED ENERGY RELATIVE TO A DIFFRACTION PATTERN OF REVOLUTION

Abstract

An optical system which is symmetrical about some axis forms a diffraction pattern around its focus F in an observation plane II.The factor of encircled energy E(W) is, apart from a normalization factor, the energy spread over the II plane inside a circle of radius W, centered on F.Although it is a good test for the quality of an optical system, the factor of encircled energy has not been used a great deal because of the lengthy calculations that its numerical determination requires. Two rapid computing methods are exposed here, with tables allowing a complete determination of E(W).