Design of the hybrid refraction-diffraction lens with wavelength 10.6 um

In this paper, combining refractive and diffractive effects, a new kind of infrared lenses with wavelength 10.6 mu m was designed and produced for CO2 laser material processing. This refractive-diffractive lens (RDL) converts a CO2 laser beam into the rectangular shape with light intensity distribution in the concave shape at x-direction. A method which employs input aperture division and geometrical transformation technique for obtaining a better initial phase distribution of the iteration is presented. The experimental results show that the desired shape of the output light beam was obtained with a high efficiency in energy utilization.