Abstract

A new pump-probe method based on the interferometric detection of local refractive index is proposed and used for determination of a non-radiative lifetime of high-laying vibronic energy states in indole dissolved in propylene glycol and two-photon excited by femtosecond laser pulses at 400 nm. The lifetime determination with picosecond resolution was physically based on the variation of the refraction index due to the population lens effect occurring in solute under two-photon excitation of indole and found to be below 40 ps.

© 2018 The Author(s)