Harvard Researchers Create Tunable Chip-Scale Device to Control Light's Handedness

The breakthrough opens new possibilities for advanced chiral sensing, optical communication, and quantum photonics.

Published on Mar. 12, 2026

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Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have created a chip-scale device that can dynamically control the "handedness" or optical chirality of light as it passes through, using a simple twist of two specially designed photonic crystals integrated with a micro-electromechanical system (MEMS).

Why it matters

Chirality, the property of an object that cannot be superimposed on its mirror image, is important in many scientific fields from pharmaceuticals to biology. The new tunable device can precisely control and detect different chiral light modes, enabling advanced applications in chiral sensing, optical communications, and quantum photonics.

The details

The device uses a twisted bilayer photonic crystal design, where two patterned silicon nitride membranes are stacked and rotated relative to each other. This built-in twist creates a left-right asymmetry that allows the device to "read" different chiral light modes. By using the integrated MEMS system to continuously vary the twist angle and spacing between the layers, the researchers can dynamically tune the device's ability to distinguish left- and right-circular polarized light.

  • The research was published in the journal Optica on March 12, 2026.

The players

Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS)

The academic institution where the research was conducted.

Eric Mazur

The Balkanski Professor of Physics and Applied Physics at Harvard SEAS, who led the research team.

Fan Du

A graduate student in Mazur's lab who was the lead author of the research paper.

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What they’re saying

“Chirality is very important in many fields of science – from pharma to chemistry, biology, and of course, physics and photonics. By integrating twisted photonic crystals with MEMS, we have a platform that is not only powerful from a physics standpoint but also compatible with the way modern photonics are manufactured.”

— Eric Mazur, Balkanski Professor of Physics and Applied Physics (Mirage News)

What’s next

The researchers say the current device is a proof-of-concept, and they hope to further develop the technology for practical applications in chiral sensing and optical communications.

The takeaway

This new tunable chip-scale device that can dynamically control the handedness of light represents an important breakthrough in the field of photonics, with potential impacts across various scientific disciplines that rely on the unique properties of chiral materials and structures.