Metalens Design Enables Reconfigurable Imaging

Facebook X LinkedIn Email
EVANSTON, Ill., March 29, 2019 — A Northwestern University research team has developed an imaging platform based on fully reconfigurable metalenses. The lenses focus light by exciting surface lattice resonances that are tuned by patterned polymer blocks on single-particle sites. The system can image at visible wavelengths and is based on arrays of coupled plasmonic nanoparticles.

The lenses are built from an array of cylindrical silver nanoparticles and a layer of polymer patterned into blocks on top of the metal array. By controlling the arrangement of the polymer patterns, the nanoparticle array can direct visible light to any targeted focal points without needing to change its structure.

Metalens for fully reconfigurable imaging, Northwestern University.

During a single imaging session, the device can evolve from a single-focus lens to a multifocal lens that can produce more than one image at any programmable 3D position. Courtesy of Northwestern University.

The team performed predictive design of the dielectric nanoblocks to create a range of 3D focusing responses. To show scalability, the researchers demonstrated a technique for erasing and writing the polymer nanostructures on the metal nanoparticle arrays in a single step using solvent-assisted nanoscale embossing. This scalable method enables different lens structures to be made in one step of erasing and writing, with no noticeable degradation in nanoscale features after multiple erase-and-write cycles.

This reconfigurable materials platform enables tunable focusing with diffraction-limited resolution and could offer prospects for highly adaptive, compact imaging. “In this study, we demonstrated a versatile imaging platform based on fully reconfigurable metalenses made from silver nanoparticles,” said professor Teri W. Odom. “During a single imaging session, our metalens device can evolve from a single-focus lens to a multifocal lens that can form more than one image at any programmable 3D position.”

For imaging operations such as zooming and focusing, most existing metalenses cannot adjust their focal spots without physical motion. One major reason, Odom said, is that the building blocks of these lenses are made of hard materials that cannot change shape once fabricated.

The Northwestern team’s reconfigurable metalens system could one day be used in portable imaging systems and optoelectronic devices. “This miniaturization and integration with detectors offers promise for high-resolution imaging in devices from small wide-angle cameras to miniature endoscopes,” Odom said.

The research was published in ACS Nano ( 

Published: March 2019
Optoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light and its interactions with different materials. The term "optoelectronics" is a combination of "optics" and "electronics," reflecting the interdisciplinary nature of this field. Optoelectronic devices convert electrical signals into optical signals or vice versa, making them crucial in various technologies. Some key components and applications of optoelectronics include: ...
A metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light at a subwavelength scale. Unlike traditional lenses made of glass or other transparent materials, metalenses do not rely on the curvature of their surface to refract or focus light. Instead, they use carefully engineered patterns of nanostructures, such as nanoscale antennas or dielectric structures, to control the phase and amplitude of light across the lens's surface....
An SI prefix meaning one billionth (10-9). Nano can also be used to indicate the study of atoms, molecules and other structures and particles on the nanometer scale. Nano-optics (also referred to as nanophotonics), for example, is the study of how light and light-matter interactions behave on the nanometer scale. See nanophotonics.
Research & TechnologyeducationAmericasNorthwestern UniversityImagingOpticsoptoelectronicscameraslensesmetalensnanoMaterialsFlat Opticsflat lensmultiplane imagingreconfigurable metalensessurface lattice resonance

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.