Work

Continuously tunable Alvarez metalenses for varifocal imaging

Year: 2026

Type: article

Abstract: Compact and lightweight lenses are essential for miniaturized varifocal imaging. We designed and fabricated an Alvarez metalens composed of two cascaded, phase-complementary metalenses. Continuous focal-length tuning is achieved by the relative in-plane lateral displacement of the two metalenses, which continuously modulates the synthesized quadratic focusing phase. To suppress aberrations, Zernike basis functions were incorporated into the phase profile of the Alvarez metalens. The focusing and imaging performance of the device was then experimentally validated at the design wavelength. With a 1 mm in-plane displacement, the Alvarez metalenses (4 mm aperture, 0.62 g weight, λ=532 nm) enabled focal length modulation from 10 mm to 150 mm, all while achieving an average diffraction efficiency of approximately 40%. The integration of an in-plane-actuation-only varifocal mechanism with ultrathin metalenses enables a highly scalable approach to miniaturizing systems for imaging, optical communications, and biomedical applications.

Source: Optics Express

DOI: 10.1364/oe.612698

Authors: Lin Liu, Qun Hao, Yunhai Zhang, Chaohui Li, Yang Cheng

Institutions: Beijing Institute of Technology, Heze University, Changchun University of Science and Technology

Language: English

Topic: Metamaterials and Metasurfaces Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funder: National Natural Science Foundation of China