Optical transmission and reflection s pectra h ave b een measured using FTIR (FTIR-6600, Jassco Co.) with the microscope unit (IRT-1000, Jassco Co.). The reflectance R(ν˜ ) spectra of the sample was measured using a 350 nm gold film a s t he reflectance reference. The transmittance T (ν˜ ) spectra from thin films were measured using Si substrate, which have no coating and double tional mode upon transition: