Diffractive optics development with stack-and-draw technique

We present a novel approach to the fabrication of diffractive optical elements. Unlike traditional diffractive optical elements, the different phase shifts are obtained through a refractive index variation by using different types of glass. This approach results in a completely flat element which is easy to integrate with other optical components. For fabrication of the test DOE structures we have used the stack-and-draw technique. This method, which was originally developed for the fabrication of photonic crystal fibres, has been modified to allow the fabrication of nanostructured micro-optical components. In this paper we present the results from proof of concept periodic checkerboards fabricated on a square and hexagonal lattice with feature sizes of 8μm and 46μm. The components were fabricated from two types of rods made of the low refractive index silicate glass and the high refractive index of lead-silicate glass. The measured characteristics of the fabricated components are presented The influence of fabrication-induced structure distortions on the optical performance of the components is discussed.