Nanowerk October 13, 2021
Most metasurfaces use monolith-like nanopillars to focus, shape and control light. The taller the nanopillar more versatile control of each color of light. But very tall pillars tend to fall or cling together. Researchers at Harvard University developed a metasurface with more than 12 million needle-like holes drilled into a 5-micrometer silicon membrane rather than very tall pillars to focus light to a single spot. The diameter of these long, thin holes is only a few hundred nanometers, making the aspect ratio nearly 30:1. The hole size variation bends the light towards the lens focus. Holes can be filled in with nonlinear optical materials, which will lead to multi-wavelength generation and manipulation of light, or with liquid crystals to actively modulate the properties of light. The metalenses were fabricated using conventional semiconductor industry processes and standard materials, allowing it to be manufactured at scale in the future…read more. Open Access TECHNICAL ARTICLEÂ
