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NEWS / FIELD NOTES
Research stories, public conversations, and the ideas that connect a flat optical surface to the world around it.
SELECTED STORIES / 2011—2026
A reverse-chronological archive of selected work—from neutral atoms and structural-color photonic crystals to the optical intelligence of living systems.
DNA origami guides gold nanoparticles into three-dimensional photonic crystals whose collective optical response produces tunable, high-reflectance, and pure structural colors—a bottom-up route to precisely designed optical materials.
Read the storyElectron microscopy: Oleg Gang / Columbia Engineering
Holographic metasurfaces generate diffraction-limited optical tweezers, trap individual strontium atoms in arbitrary two-dimensional geometries, and scale to a demonstrated 360,000-trap array—turning a planar optic into a path toward large, programmable neutral-atom systems.
Read the storyImage: Nanfang Yu Lab
Traditional flat knitting becomes a scalable electromagnetic manufacturing platform: metallic and dielectric yarns form flexible, lightweight radio-frequency metasurfaces that can be folded, carried, and deployed.
Read the storyPhoto: Michael Carter and Nanfang Yu / Columbia Engineering
Leaky-wave metasurfaces transform a mode confined on a photonic chip into designer free-space fields, controlling amplitude, phase, and polarization together. The interface connects integrated processing with communications, holography, sensing, and atomic physics.
Read the storyImage: Heqing Huang, Adam Overvig and Nanfang Yu / Columbia Engineering
A wavelength-selective nonlocal metasurface shapes chosen colors while remaining transparent to the rest of the spectrum. The same principle points toward lighter augmented-reality optics and more compact multiwavelength systems for cold atoms.
Read the storyIllustration: Nanfang Yu, Stephanie Malek and Adam Overvig / Columbia Engineering
Infrared hyperspectral imaging revealed that butterfly wings are living thermal systems. Their nanostructures selectively enhance radiative cooling around veins and scent patches, while the wings also sense the direction and intensity of sunlight.
Read the storyInfrared imaging: Nanfang Yu and Cheng-Chia Tsai
A hierarchically porous polymer replaces pigment with light-scattering air voids. It reflects sunlight, emits thermal radiation to the sky, and achieves passive cooling in both arid and humid climates through a process compatible with paint-like fabrication.
Read the storyPhoto: Jyotirmoy Mandal / Columbia Engineering
The Saharan silver ant's triangular hairs solve two thermal problems at once: they reflect solar radiation and help the insect shed heat in the mid-infrared. The discovery linked evolutionary optics to a new language for passive cooling surfaces.
Read the storyImages: Norman Nan Shi and Nanfang Yu
In Federico Capasso's group at Harvard, lead author Nanfang Yu and colleagues showed that subwavelength optical antennas could write abrupt phase changes onto an interface, producing generalized laws of reflection and refraction. Led by Capasso as PI and corresponding author, the 2011 Science work became a foundation of modern metasurfaces.
Read the storyImage courtesy of Nanfang Yu / Harvard SEAS