UV-curable resin microlenses on optical pillars for optical interconnect

Abstract

A unique combination of pillar and microlens is demonstrated to enable easy coupling between VCSEL layers and a multi-layer/channel optical printed wiring board. A number of uniform pillars having a microlens on the top were fabricated on a substrate using UV-curable resin by masktransfer self-written waveguide and dipping methods. Ray-trace analysis indicated that the focusing characteristics could be controlled by adjusting the pillar height and the microlens radius of curvature. Tolerance coupling efficiency between pillar height and microlens radius of curvature is acceptable. Light propagation measurements showed that uniform power was obtained from all top microlenses of the 3 × 4 pillar array on a slide glass. Studies of the reproducibility of microlens-on-pillar fabrication using the dipping method show a positive outcome. As a result, optical coupling efficiency is expected to be improved in optical interconnect applications.

Polymer Spot Size Expanders for High Efficiency Optical Coupling in Optical Interconnection

“…An SSE composed of a pillar and microlens was fabricated on the end of the HiNA fiber. To ensure that the SSE and HiNA fiber aligned precisely in the submicron order, the pillar was fabricated using a conventional, precisely controlled photomask aligning process, and the microlens was fabricated on the pillar by a dipping process [14].…”

“…Next, a microlens was fabricated on the pillar using the dipping method. The dipping method is convenient for fabricating microlenses in a limited area [14]. The diameter of the microlens fabricated on the end face of the pillar depends on the diameter of the pillar.…”