<title>Realization of a vertical integration scheme for polymer waveguides by a novel stacking technology</title>

Abstract

The rapid growth of communication continuously demands an increasing number of data transport channels. We present an approach towards a substantial growth of channel numbers within the integrated optical waveguide chip. This is accomplished by introducing a vertical integration scheme, which is implemented with stacked polymer waveguides. To meet the requirements of stacked optical waveguide devices concerning index distributions, cross-sections and alignment precision, a novel fabrication technology has been developed. During the stacking process several fundamental problems, e.g., index inhomogenities caused by diffusion effects and distortion of the desired waveguide structures with increasing stack height, have to be avoided. In addition, the non-linear index change of the polymer materials during polymerization has to be carefully considered to come to well defined index distributions, which are the same in all layers. A solution meeting these requirements is presented using standard processes like UV patterning in combination with thermal curing steps.