Enhancing reflectivity of tantalum oxide coatings through plasma spraying and annealing techniques

Tantalum oxides, widely used as a high-reflectivity infrared material in aerospace and optoelectronics, often experiences a significant reduction in coating performance post-plasma spraying due to the emergence of oxygen defects. To overcome this shortcoming, this study comprehensively examined the effects of spray parameters and annealing processes on coating reflectivity. Our findings revealed that while optimizing spray parameters can modify micromorphology, these changes exert limited improvement on reflectivity (<2%). Conversely, muffle and laser annealing markedly enhance reflectivity by altering the surface composition and the valence of tantalum. Notably, post-laser annealing increased the reflectivity to 57 % from the original 12 % at 1070 nm. These results offer valuable insights into the development of high-reflectivity tantalum oxide coatings.