Circular-target-style bifocal zoom metalens

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Optical zoom is crucial for image magnification in various applications like photography and microscopy.
• Traditional zoom lenses are bulky, limiting their use in compact electronic and photonic systems.
• Metalenses offer a versatile and flexible alternative for miniaturized and lightweight optical zoom solutions.

Purpose of the Study:

• To propose and demonstrate an ultra-thin, lightweight, and compact bifocal zoom metalens.
• To achieve high-quality image magnification with a single metalens device.
• To explore the potential of metalenses in miniaturized imaging and wearable devices.

Main Methods:

• Design of a bifocal zoom metalens comprising a conventional circular sub-aperture and a sparse annular sub-aperture with distinct focal lengths.
• Numerical simulations to evaluate imaging resolutions and performance.
• Experimental validation of the metalens's zoom capabilities and imaging resolution.

Main Results:

• Demonstrated imaging resolutions of 164 lp/mm at 1× magnification and 117 lp/mm at 2× magnification.
• Achieved clear zoom images of a dragonfly wing pattern, highlighting biological imaging capabilities.
• Successfully validated the metalens's performance both numerically and experimentally.

Conclusions:

• The developed bifocal zoom metalens offers a compact and lightweight solution for optical zoom.
• This metalens technology shows significant potential for applications in integrated optical systems, miniaturized imaging, and wearable devices.
• The study provides a novel approach for advancing metalens-based optical zoom capabilities.