Numerical Investigation of Spherical Gradient Index Microlenses with the Wave Propagation Method

Abstract

The ion exchange process in glass is an important fabrication method for waveguides as well as for gradient index microlenses [1]. The diffusion response and therefore the shape of the gradient index distribution is variable due to many exchange parameters. Different glass-types and different exchange pairs, showing different degree of non-linearity of the exchange process influence the steepness of the profiles, whereas the symmetry of the index-distribution is changeable by mask-design [2]. For the user of microlenses as well as for the manufacturer, it is important to know the imaging properties of the different index profiles.