At a Glance
- KAIST researchers have created a high-resolution spectrometer smaller than a fingernail, pioneering a design that could integrate advanced light analysis into smartphones and other portable electronics.
- Conventional spectrometers rely on bulky prisms that separate light over distance, a design limitation that has long prevented their widespread use in everyday mobile technology.
- The team’s innovative approach uses an engineered metasurface that scrambles light into a unique speckle pattern with a distinct fingerprint for each color.
- By mounting this metasurface directly onto an image sensor, the device captures the light pattern, allowing software to reconstruct the original wavelength precisely from a single image capture.
- This breakthrough technology enables powerful daily applications like mobile food analysis, skin health diagnostics, and on-the-spot environmental pollution detection, moving beyond simple color sensors.
Researchers from the Korea Advanced Institute of Science and Technology (KAIST) have developed an ultra-compact, high-resolution spectrometer smaller than a fingernail. This breakthrough could allow advanced light-analysis technology to be integrated into smartphones and wearable devices. The new device overcomes traditional spectrometers’ size and complexity limitations, potentially bringing laboratory-grade material analysis to everyday applications. The work, led by a team in the Department of Bio and Brain Engineering, was published in Science Advances.
Spectrometers are scientific instruments that analyze a material’s properties by breaking down light into its constituent wavelengths, much like a prism that separates white light into a rainbow. For decades, these devices have relied on dispersive elements, such as prisms and gratings, which require a significant physical distance to spread the light out and achieve high resolution. This fundamental design principle has kept high-performance spectrometers bulky and complex, restricting their use in specialized industrial and scientific settings and preventing their adoption of portable, consumer-level technology.
To solve this challenge, the KAIST team abandoned the traditional approach. Instead of a prism, they engineered a novel component called a double-layer disordered metasurface. A metasurface is an ultra-thin, engineered surface covered in structures smaller than the wavelength of light, allowing it to manipulate light in complex ways. This particular metasurface acts as a random scrambler, converting incoming light into a unique, messy-looking light pattern called a “speckle.” Crucially, each specific wavelength of light produces its own distinct and predictable speckle pattern, like a fingerprint for every color.
By mounting this metasurface directly onto a standard image sensor, the researchers created a complete spectrometer system less than 1 centimeter in size. When light hits the device, the sensor captures the unique speckle pattern, and powerful reconstruction algorithms instantly determine the exact wavelength of the original light. This innovative method achieves a spectral resolution of around 1 nanometer across a wide range of visible light.
According to Mooseok Jang, the study’s corresponding author and a professor at KAIST, this technology can move beyond the simple red, green, and blue (RGB) sensors standard in today’s devices. “We anticipate various applied research for this technology, which expands the horizon of laboratory-level technology to daily-level machine vision technology for applications such as food component analysis, crop health diagnosis, skin health measurement, environmental pollution detection, and bio/medical diagnostics,” he said.
References
- Lee, D., Song, G., Lee, C., Lee, C., & Jang, M. (2025). Reconstructive spectrometer using double-layer disordered metasurfaces. Science Advances, 11(22), eadv2376. https://doi.org/10.1126/sciadv.adv2376
- The Korea Advanced Institute of Science & Technology. (2025, June 13). A high-resolution spectrometer that fits into smartphones. Phys.Org; The Korea Advanced Institute of Science & Technology. https://phys.org/news/2025-06-high-resolution-spectrometer-smartphones.html
