Ionic liquid-based variable focus electrowetting optics with bandwidths spanning the visible to mid-infrared

TL;DR

This paper introduces ionic liquid-based electrowetting lenses and prisms capable of operating across a broad spectrum from visible to mid-infrared, enabling versatile adaptive optics for various applications.

Contribution

The work presents novel ionic liquid-based electrowetting devices that operate from 400 to 5000 nm, surpassing traditional polar liquid devices in spectral bandwidth.

Findings

Electrowetting lenses tune over 20 diopters at multiple wavelengths.

Prism elements achieve a steering angle of 0.56° at 1550 nm.

Devices operate effectively from visible to mid-infrared wavelengths.

Abstract

Infrared optical materials and devices are important for a wide range of applications in the defense, scientific, and consumer markets. For imaging, spectroscopy, microscopy and persistent surveillance, adaptive optic systems that span the visible to infrared region are particularly useful. We address this need with novel electrowetting lens and prism elements that operate from 400 to 5000 nm. In contrast to conventional electrowetting devices that use polar liquids, limited by high absorption in the infrared region, we present room-temperature ionic liquid-based (RTIL, N-Propyl-Nmethylpyrrolidinium Bis(fluorosulfonyl)imide, Pyr1333a, Solvionic) lens and prism elements with unprecedented spectral bandwidths. Our electrowetting lenses tune over 20 diopters and have been demonstrated at 588, 1550 and 3000 nm wavelengths. Additionally, we have demonstrated prism elements with a steering angle of 0.56{\deg} at 1550 nm.