Optical absorption of surfaces modified by carbon filaments

The reflectivities of modified carbon, silicon, and quartz surfaces have been measured from 1 to 25-microm wavelengths. Surfaces were modified by either bombarding carbon surfaces with ~1000-eV Ar(+) ions or growing carbon filaments on them by catalytic chemical vapor deposition from hydrocarbon/hydrogen mixtures. The surfaces were highly absorbing through most of this wavelength region with most surfaces showing a rise in reflectivity beyond ~15 microm. The reflectivity of one modified Si surface was below 1% throughout the entire wavelength region and may be the most highly absorbing surface yet found.