Investigation of phonon, plasmon, surface polariton,and plasmon- LO phonon coupling modes in dopedGa1-xNxAs

摘要

Polarized infrared Fourier transform spectroscopy is employedto study the optical properties of doped Ga1-x NxAs. The dispersion curveof coupled LO phonon- plasmon modes were calculated from thepolarized infrared reflectivity data. The GaNAs layer shows two-modebehavior in the infrared spectral range, a GaAs-like and a GaN-likesublattices. We detect the transverse optic phonon of GaN sublatticearound 470 cm-1 The origin of the sharp feature in p-polarizationreflectivity about 300 cm-1 as well as the dip at LO phonon frequency ofGaAs sublattice are due to Brewster mode. The Brewster mode is couplestrongly to plasmon mode. Attenuated total reflection spectroscopy hasbeen used to excite and investigate surface plasmon and surfacepolariton.