Excimer laser ablation used for the fabrication of micro-optic phase and diffraction elements

Abstract

Micro Optics frequently require the fabrication of complex 3D structures with surface qualities and metrological tolerances that challenge many manufacturing techniques. In this paper we describe two excimer laser ablation techniques for creating spiral phase modulation structures and a technique for fabricating a diffractive optical structure. The spiral phase structures are intended to be used to convert a 780nm TEM00 laser beam into the 'doughnut mode' TEM01* field, and the diffractive structure is used to create the 'double-D' TEM01 mode in the transmitted first order diffraction pattern. Each of the techniques involve the use of mask projection excimer laser ablation. One of the techniq..