Duke University engineers develop fastest pyroelectric photodetector capable of capturing light in picoseconds

A new Duke University photodetector captures light in 125 picoseconds using metasurfaces, enabling high speed multispectral imaging for medicine and agriculture.

By: AXL Media

Published: Mar 5, 2026, 3:19 AM EST

Source: The information in this article was sourced from Duke University

Overcoming the Speed Limitations of Thermal Sensing

Traditional photodetectors used in digital imaging typically rely on semiconductors that convert visible light into electrical signals. However, these materials are limited by their narrow spectral range, similar to the constraints of human vision. To detect light outside the visible spectrum, researchers often use pyroelectric detectors, which generate signals by sensing heat. Historically, these devices have been considered slow and bulky because they require thick materials to absorb enough energy to produce a measurable thermal change. The new breakthrough from Duke University fundamentally alters this paradigm by integrating near perfect absorbers with ultrathin materials to achieve unprecedented response times.

Engineering the Plasmonic Metasurface

The core of the record breaking device is a meticulously engineered metasurface designed to trap light with extreme efficiency. This structure consists of silver nanocubes placed on a transparent film, situated only 10 nanometers above a thin layer of gold. When incoming light strikes the nanocubes, it excites electrons in the silver and traps the energy through a phenomenon known as plasmonics. The specific frequency of light the device captures is determined by the size and spacing of these nanocubes, allowing the detector to be tuned to various parts of the electromagnetic spectrum.

Achieving Record Breaking Response Times

Recent refinements to the detector design have pushed its operational speed to 2.8 GHz, meaning it can generate an electrical signal in just 125 picoseconds. This performance is hundreds or even thousands of times faster than standard commercial pyroelectric detectors, which usually operate in the microsecond range. To achieve this, researchers optimized the metasurface into a circular configuration, which increased the surface area for light collection while simultaneously shortening the path that electrical signals must travel. Thinner pyroelectric layers and improved electronic circuitry further contributed to the significant reduction in latency.