The 1086 cm−1 phonon decay routes in the O- and E-directions in calcite from Raman scattering

The differences in the Raman linewidth of 1086 cm−1 A1 g mode were measured for O- and E-waves in calcite crystals. The linewidth for the O-wave was found to be larger than the E-wave phonon excited 1086 cm−1 mode, indicating a faster 1086 cm−1 optical phonon dephasing lifetime T2 for generating O-wave than E-wave modes. The difference in linewidths is attributed to dispersion phonon decay ω vs. k difference in decay phonon pathways in the O- and E-directions.