Millimeter-scale focal length tuning with MEMS-integrated meta-optics employing high-throughput fabrication

TL;DR

This paper presents a high-throughput, CMOS-compatible fabrication process for miniaturized, electro-mechanically tunable meta-optic lenses with the largest reported focal length adjustment at low voltage, enabling compact infrared imaging systems.

Contribution

It introduces a novel nanofabrication method for large-aperture meta-optics with integrated MEMS actuators, achieving significant focal length tuning at low power.

Findings

Achieved 3.1 mm (200 diopters) focal length tuning with less than 40 V.

Developed a CMOS-compatible, high-throughput fabrication process.

Demonstrated the largest low-power focal length tuning in meta-optics to date.

Abstract

Miniature varifocal lenses are crucial for many applications requiring compact optical systems. Here, utilizing electro-mechanically actuated 0.5-mm aperture infrared Alvarez meta-optics, we demonstrate 3.1 mm (200 diopters) focal length tuning with an actuation voltage below 40 V. This constitutes the largest focal length tuning in any low-power electro-mechanically actuated meta-optic, enabled by the high energy density in comb-drive actuators producing large displacements at relatively low voltage. The demonstrated device is produced by a novel nanofabrication process that accommodates meta-optics with a larger aperture and has improved alignment between meta-optics via flip-chip bonding. The whole fabrication process is CMOS compatible and amenable to high-throughput manufacturing.