Fabrication and characterization of hybrid-glass-based axicons

We introduce a process for applying directly UV photopatternable materials and processing methods for the fabrication of binary diffractive optical elements.
We design and model a binary axicon—an optical element that produces an almost diffraction free beam at a specified distance from the element. We also synthesize sol-gel-based hybrid glass materials and tailor their processing parameters to fit to the demands of the axicon design.
A grating periodicity of 2 μm, an 850-nm structure depth, and certain morphological properties are required to meet the design parameters.
The materials are synthesized using zirconium(IV)isopropoxide, methacrylic acid and methacryloxypropyltrimethoxysilane as deposition material precursors. We determine the morphological and shape characteristics of the fabricated axicons as a function of the lithographic exposure parameters. The optical characteristics of the axicons are measured in terms of the axial and radial intensity profiles.
The difference between the modeled and measured results is explained.