Rewritable Optical Components For 2D Light Waves

A team from Harvard University’s John A. Paulson School of Engineering and Applied Sciences (SEAS) has developed rewritable optical components for surface lightwaves.

When a wave of light is confined on a 2D plane by certain materials, it becomes something known as a polariton — a particle that blurs the line between light and matter. Polaritons enable light to be tightly confined to the nanoscale, even potentially to the thickness of a few atoms. That capability poses interesting implications for the future of optical circuits. Unlike electronic integrated circuits, integrated optics is difficult to miniaturize with commonly used materials: All of the current methods of controlling light are 3D.

“The ability to control and confine light with fully reprogrammable optical circuits is vital for future highly integrated nanophotonic devices,” said Michele Tamagnone, a postdoctoral fellow in applied physics at SEAS.

In previous research, the team demonstrated a technique to create and control polaritons by trapping light in a flake of hexagonal boron nitride. In this study, the researchers put those flakes on the surface of a material known as GeSbTe (GST) — the same material used on the surface of rewriteable CDs and Blu-ray discs.

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