A refracting system is designed for transforming an annular Gaussian laser beam into a circular Bessel beam. The slope of the input and output surfaces fitted well with a sixth-order polynomial. The radii of curvature of the resulting aspheric surfaces are found to vary smoothly over the surface. The diffraction-free length for this system is found to be 59.4735 m at 633 nm. (C) 1998 Optical Society of America. [References: 11]
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