Numerical analysis of the ISO alternative methods for propagation factor measurements of coherent stigmatic beams

Abstract

The paper presents analysis of the alternative methods for measurements of beam widths and beam propagation factors proposed by ISO 11146 standart based on the developed efficient numerical methods for calculation of focussing of the beams with complex spatial structure. Concrete calculations oft alternative propagation factors performed for a number of test beams have demonstrated that the proposed correlation factors ci do not establish the unambiquous relation betweeen M2σ and the alternative factors M2i. Therefore, application of the alternative propagation factors M2i, at least for the coherent beams, is not substantiated.