Co-Doped ErFeO for Dual-Band Laser Absorption with High-Temperature Stability.

The development of multi-band laser suppression materials has been driven by the limitations of single-band laser suppression materials. Inorganic ceramic materials, compared with organic laser suppression materials, photonic crystals, and metamaterials, offer significant advantages in fabrication methods and environmental stability. In this study, Co ions, with relatively higher electronegativity, were introduced to substitute some Fe ion sites in ErFeO. This substitution caused distortion in the crystal structure, reduced the unit cell volume, and altered the band structure. As a result, the band gap was reduced compared with that of ErFeO, and the unique energy level transitions of Er ions were activated. This led to dual-band laser suppression with reflectances of 22.16% at 1064 nm and 35.63% at 1540 nm. Furthermore, after high-temperature testing at 1100 °C in air, the laser absorption performance could still be maintained with the intensity retention above 95%. This unique strategy for improving the band structure provides significant potential for applications in laser suppression.