Next-Generation Optical Sensor Can Read Photon Spin Across UV-to-Infrared Wavelengths

Why It Matters

The ability to read photon spin over a broadband range with a single, high‑sensitivity sensor could accelerate quantum communication, cryptography, and advanced imaging, providing a scalable hardware foundation for next‑generation secure optical technologies.

Summary

Researchers at Daegu Gyeongbuk Institute of Science and Technology (DGIST) have created a quantum‑dot photodiode that can detect the spin of photons—circularly polarized light—across an ultra‑wide spectral range from ultraviolet to short‑wave infrared. By embedding a chiral layer in the electron‑transport pathway rather than the light‑absorbing material, the device selectively transmits electrons of a given spin, producing a measurable current difference that reveals photon spin. The sensor matches the intensity and wavelength performance of commercial silicon photodetectors and achieves a sensitivity of 10¹² Jones, comparable to high‑end commercial detectors. The findings were published in Advanced Materials and suggest a new platform for quantum‑optical applications.