Tailoring lens functionality by 3D laser printing

Conversion of a Gaussian beam into a top-hat beam or to an annular beam is demonstrated using 3D direct laser printing. Micron-scale refractive phase elements were designed and printed directly on standard commercially available lenses. These structures modify the phase of the incoming beam into either three intensity-flattened profiles, having line, square, or circular shapes, or to an annular beam profile. This method to functionalize lenses opens new and exciting opportunities for compact and robust beam shaping, as well as for reduction of the aberrations of the lens itself.