The August 2026 cover story of Photonics Views explores the latest breakthrough in Raman spectroscopy experiments. The study shows how researchers finally record a clear Raman spectra of metallic oxygen across a broad range of pressure range.
Raman spectroscopy is one of the most powerful tools for investigating the structure of materials, yet some systems remain beyond its practical reach due to extremely weak scattering signals. Metallic oxygen is one such example. Although oxygen is known to become metallic at high pressures, its vibrational properties have remained largely inaccessible for more than three decades because of the combined challenges of weak Raman scattering, high reflectivity, and the demanding environment of diamond anvil cell experiments. Using highly stable single-frequency laser sources at 532 nm, 660 nm, and 785 nm, we successfully recorded clear Raman spectra of metallic oxygen across a broad pressure range.
Read more about the experiment on Photonics Views.
