DIRECT FOCUSING MODIFICATIONS OF ELLIPTIC GAUSSIAN-BEAM BY NONCIRCULAR APERTURES

For focusing the elliptical Gaussian beam directly, the effects of a n on-circular aperture on the focusing properties are studied. The focus ing properties for different shapes of apertures, which include a circ le, an ellipse and a rectangle, are calculated and compared. Moreover, for different elliptical Gaussian beams, an empirical aperture select ion rule that can be used to circularize the focusing spot is proposed . The energy transmission ratios are also considered in this paper.