Abstract Samples made of hot work steel grade H11 were pulse plasma nitrided in hydrogen nitrogen mixture and post-nitrocarburized in carbon-containing discharge. Microhardness measurements, optical microscopy, SEM, Raman, XRD and infrared spectra analyses revealed the existence of a thin epsilon + γ′ compound zone onto 150 μm thick diffusion layer after plasma nitriding, while a dense 3 μm thick amorphous hydrogenated carbon nitride overcoating was grown during plasma post-processing in carbon-containing atmosphere. On the surface of plasma deposited hydrogenated carbonitride films intended for tribological applications non-regular “arrays” of different size conductive clusters were found. Similar arrays architecture, when obtained intentionally, could be used for the resonant optical connections in nanooptics and macro optics. Some coupled arrays, like the fiberoptic waveguide in fiber optics interferometers, were also observed. Computer simulation showed that in the case of similar geometry spherical Ag clusters deposited onto dielectric substrate the resonant interaction of light beam with coupled arrays is possible resembling to the light beam coupler on nanoscale.