Voltage brings new metalens into focus

The advance from researchers at Cornell University's School of Applied and Engineering Physics and Samsung's Advanced Institute of Technology is said to be the first of its kind.

The proof of concept could lead to a range of compact varifocal lenses for use in imaging applications including satellites, telescopes and microscopes, which traditionally focus light using curved lenses that adjust using mechanical parts. In some applications, moving traditional glass or plastic lenses to vary the focal distance is not practical due to space, weight or size considerations.

Adaptive metalens maintains focus with artificial muscle

Metalenses are flat arrays of nano-antennas or resonators, less than a micron thick, that act as focusing devices. Until now, once a metalens was fabricated, its focal length was hard to change, according to Melissa Bosch, doctoral student and first author of a paper detailing the research in the American Chemical Society's journal Nano Letters.

The innovation involved merging a metalens with the well-established technology of liquid crystals to tailor the local phase response of the metalens. This allowed the researchers to vary the focus of the metalens in a controlled way by varying the voltage applied across the device.