Coatings that absorb as much of the energy of high-powered lasers as possible without breaking down are essential for optical power detectors that measure the output of such lasers, which are used, for example, in military equipment for defusing unexploded mines. The new material improves on NIST's earlier version of a spray-on nanotube coating for optical power detectors and has already attracted industry interest.

"It really is remarkable material," NIST co-author John Lehman says. "It's a way to make super-nanotubes. It has the optical, thermal and electrical properties of nanotubes with the robustness of the high-temperature ceramic."

The composite was developed by Kansas State. NIST researchers suggested using toluene to uniformly coat individual nanotubes with a ceramic shell. They also performed damage studies showing how well the composite tolerates exposure to laser light.