[摘要]：Decay of the strongest optical phonon mode in KTiOPO4 was directly traced using femtosecond coherent anti-Stokes Raman scattering spectroscopy. Dephasing of the Raman active mode at similar to 700 cm(-1) proceeds with the nonlinear polarization dephasing time of 495 +/- 610 fs. The dephasing is solely due to the phonon energy decay with corresponding homogeneous linewidth of 21.4 +/- 60.5 cm(-1). Low temperature linewidth of 14.7 cm(-1) is estimated from our data assuming that down-conversion phonon relaxation process is dominant. Our results can help to understand stimulated Raman generation and oscillation of Stokes wave in laser systems where Raman gain is critically dependent on dephasing time. (C) 2011 American Institute of Physics. [doi:10.1063/1.3664218]
