  Inclusions of sp-hybridised, trans-polyacetylene [trans-(CH)x] and
poly(p-phenylene vinylene) (PPV) chains are revealed using resonant Raman
scattering (RRS) investigation of amorphous hydrogenated carbon (a-C:H) films
in the near IR - UV range. The RRS spectra of trans-(CH)x core Ag modes and the
PPV CC-H phenylene mode are found to transform and disperse as the laser
excitation energy \hbar{\omega}L is increased from near IR through visible to
UV, whereas sp-bonded inclusions only become evident in UV. This is attributed
to \hbar{\omega}L probing of trans-(CH)x chain inhomogeneity and the
distribution of chains with varying conjugation length; for PPV to the resonant
probing of phelynene ring disorder; and for sp segments, to \hbar{\omega}L
probing of a local band gap of end-terminated polyynes. The IR spectra analysis
confirmed the presence of sp, trans-(CH)x and PPV inclusions. The obtained RRS
results for a-C:H denote differentiation between the core Ag trans-(CH)x modes
and the PPV phenylene mode. Furthermore, it was found that at various laser
excitation energies the changes in Raman spectra features for trans-(CH)x
segments included in an amorphous carbon matrix are the same as in bulk
trans-polyacetylene. The latter finding can be used to facilitate
identification of trans-(CH)x in the spectra of complex carbonaceous materials.
