Laser-ablation-based technique for flexible fabrication of microlenses in polymer materials

Laser ablation is a versatile technique for fabricating microstructures on polymer surfaces. Due to the nature of the process, the fabrication of the microstructure can take place in a very late stage of a heterogeneous assembly. This makes laser ablation very attractive for fabricating micro-optical components on opto-electronic assemblies in comparison to other fabrication techniques like injection molding and embossing. In this paper we will report on the first experimental results of microlens fabrication with excimer laser ablation techniques. By scanning the polymer surface along multiple circular paths with a circular beam of a pulsed excimer laser, one is able to obtain a lens shape with arbitrary focal distance and diameter. Important issues such as the choice of ablation parameters, the selection of scanning path and the performance of the resulting laser ablated lens will be discussed