Microscopic Mirrors Propel Quantum Networks

New fabrication method produces high-performance, curved optical mirrors for quantum computing and sensing applications.

Published on Feb. 27, 2026

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Researchers at Harvard University have developed a new microfabrication method to create some of the smallest, smoothest mirrors ever made for controlling single particles of light, known as photons. These mirrors could play key roles in future quantum computers, quantum networks, integrated lasers, environmental sensing equipment, and more.

Why it matters

Optical resonators, which use mirrors to trap and intensify light, are fundamental building blocks for many light-based devices. However, quantum applications require even smaller and lower-loss optical cavities than conventional technologies. The new fabrication method allows for precise control over the mirror's curvature and the wavelengths of light it reflects, making it highly scalable and versatile for a range of quantum and photonic applications.

The details

The new microfabrication process starts with a silicon wafer and uses thermal oxidation to grow a smooth silicon oxide layer. This layer is then coated with precisely engineered transparent oxide layers to form a dielectric mirror. When the mirror coating is freed from the silicon wafer, it naturally buckles into a curved shape due to built-in mechanical stress, creating a high-quality optical mirror. This allows the researchers to control the mirror's curvature and the wavelengths it reflects.

  • The research was published in February 2026.

The players

Marko Lončar

The Tiantsai Lin Professor of Electrical Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS).

Mikhail Lukin

The Joshua and Beth Friedman University Professor in the Department of Physics at Harvard University.

Kiyoul Yang

Assistant professor of electrical engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS).

Sophie Ding

Former graduate student and lead author of the study.

Brandon Grinkemeyer

Postdoctoral researcher in the Lukin lab at Harvard University.

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What they’re saying

“We needed these high-quality photonic interfaces to create efficient ways to have single photons interact with single atoms, allowing for fast, high-fidelity quantum networking.”

— Brandon Grinkemeyer, Postdoctoral researcher

“In microfabrication, we are sometimes confined by the thought that surface roughness is defined by the etch or the mask, and we try very hard to optimize them. But when we are using the properties of the materials, we can do a lot less of that and have more robust results.”

— Sophie Ding, Former graduate student

What’s next

The researchers plan to further develop and scale their microfabrication method to create even smaller and higher-performance optical cavities for a variety of quantum and photonic applications.

The takeaway

The new microfabrication technique for creating high-quality, curved optical mirrors represents a significant advancement in the field of quantum optics and could enable breakthroughs in quantum computing, quantum networking, and integrated photonics.