Novel transient scattering technique for femtosecond dephasing measurements.

A novel transient scattering technique is proposed for femtosecond dephasing time measurements. This technique provides several advantages compared with existing techniques for time-domain dephasing measurements, including resolution below the pulse width, insensitivity to rapid energy relaxation, and clear demarcation between homogeneous and inhomogeneous broadening. We report experimental results for the dye Nile blue in solution; the dephasing time T(2) is determined to be less than 20 fsec.