Formation and Integration of a Ball Lens Utilizing Two Phase Liquid Technology

This study presents a novel microlens formation technology to implement a polymer ball lens in liquid medium. The highly symmetric ball lens is achieved due to the lower gravity influence in liquid. The microlens´ diameter is controlled by the volume of the dispensed polymer. Moreover, it is easy to dispense, form, and align the liquid-phase polymer microlens with MEMS structures while processing in liquid. Thus, the microlens can either be a discrete optical component, or directly integrated with MEMS structures during the process to form a SiOB (silicon-optical-bench). To date, ball lenses with diameter ranging 200mum ~ 600mum and surface roughness < 10 nm are fabricated. A typical sphericity is 8.6mum for a 525mum diameter ball lens. The integration of such polymer micro ball lens on SiOB is also demonstrated.