Micro-optical elements for optical wireless applications

Customized high-contact-angle microlenses are presented for optical wireless communication (OWC) and optical wireless location (OWL) applications. These microlenses are fabricated by way of an electro-dispensing technique to establish wide field-of-views (FOVs). Each microlens is formed from dispensed UV-curable polymer with pressure-control defining the microlens volume and a voltage on the metal needle tip defining the microlens shape (by way of electrowetting). UV curing is then applied. Microlenses with FOVs up to 90 degrees are fabricated for high-density integration above a CMOS imaging sensor for wide-FOV operation in emerging OWC and OWL applications. Both theoretical ray-tracing analyses and experimental imaging results are presented with good agreement.