Award Winner Most optically black materials rely on a textured surface or coating. The Broadband Optical Absorber is the first three-dimensional bulk optical absorber. It is easily fabricated to net shape and is exceptionally damage resistant compared with optically black coatings. Other optically black components rely on fine-scale surface structure formed by etching, anodizing or coating.
Etched structures are effective only for wavelengths smaller than their surface features.
Anodized and coated surfaces are highly vulnerable to damage. The Broadband Optical Absorber is a low-density carbon structure with large open spaces. Because its absorption is a bulk property, it is not altered by surface damage. The open space keeps spectral reflectance well under 1 percent for all wavelengths from 2 to 50 um. Scatter is isotropic with no specular component of reflection.