A Study On Propagation Properties Of Elegant Beams

The present thesis is mainly concerned with the elegant beam propagation characterization. Firstly intensity distributing of several kinds of elegant beams is introduced. Also conducted is a review on the generalized Huygens-Fresnel diffraction integral (Collins formula), beam characteristic parameters and their definitions. On such basis, the elegant beams propagation is studied in detail. The main work of this dissertation is summarized as follows:·Starting from the generalized Huygens-Fresnel diffraction integral (Collins formula), the closed-form filed distribution of elegant Hermite Cosh-Gaussian beams in the free space is derived. And intensity distribution is studied in the free space. Then based on the second-order moment method, the closed-form expression of the beam width is obtained, and the beam waist width and waist location for elegant Hermite Cosh-Gaussian beams are also deduced in the free space.· Focusing properties of elegant cosh square Gaussian and Sinh square Gaussian beams through a thin lens are studied in detail. And intensity distribution on the axis and focusing intensity distribution are analyzed. Also focal shift of Sinh square Gaussian beams are studied. Then based on the second-order moment method, the closed-form expression of the beam width is obtained, and the beam waist width and waist location for elegant cosh square Gaussian and Sinh square Gaussian beams are also deduced. A comparative study of the waist location and the real focal point (the point of the maximum intensity on the axis) is made.·Starting from the Collins formula, intensity distribution properties of elegant sin-Gaussian and elegant cosh-Gaussian beams are studied. In this paper beam widths in elegant sin-Gaussian and elegant cosh-Gaussian beams through the thin lens are taken as a typical example, a detailed comparative study of the second-order moment method and the encircled-power method is made and numerical calculations results are illustrated. The conclusion made in this paper is useful for some practical applications.