Dielectric Liquid Microlens With Switchable Negative and Positive Optical Power

We propose an adaptive dielectric liquid microlens whose focal length can be tuned from negative to positive or vise versa. The biconcave polymer base in the lens cell not only generates an inhomogeneous electric field, inhibits drifting of the droplet, and reduces the operating voltage but also induces a negative optical power. Pairing with the top subliquid lens, the whole lens exhibits a tunable negative and positive optical power under different driving voltages. To prove this concept, we fabricated such a dielectric liquid microlens and evaluated its performance. The biconcave polymer base can be particularly designed to obtain different dynamic range as desired.