  The infrared range optical absorption mechanism of Carbon-Copper composite
thin layer coated on the Diamond-Like Carbon (DLC) buffer layer has been
investigated. By consideration of weak interactions between copper
nanoparticles in their network, optical absorption is modeled using their
coherent dipole behavior induced by the electromagnetic radiation. The copper
nanoparticles in the bulk of carbon are assumed as a chain of plasmonic
dipoles, which have coupling resonance. Considering nearest neighbor
interactions for this metallic nanoparticles, surface plasmon resonance
frequency ({\omega}\neg0) and coupled plasmon resonance frequency
({\omega}\neg1) have been computed. The damping rate versus wavelength is
derived which leads to the derivation of the optical absorption spectrum in the
term of {\omega}\neg0 and {\omega}\neg1. The dependency of the absorption peaks
to the particle-size and the particle mean spacing is also investigated. The
absorption spectrum is measured for different Cu-C thin films with various Cu
particle size and spacing. The experimental results of absorption are compared
with the obtained analytical ones.
