Abstract

A few years ago, it was demonstrated that, in a time-resolved four-wave mixing (TFWM) experiment, the ultimate resolution equals the coherence time of the light τ_c, rather than the pulse duration τ_L. Therefore, long-duration broadband laser pulses, with τ_c<τ_L can be used for the investigation of ultrafast relaxation processes. However, the short-time- resolution property was observed to be mainly effective for the measurement of optical dipole decay rates)dephasing rate). Extension to the measurement of excited-level lifetimes was attempted by several groups,¹ but spurious structures often obscure the pertinent component of the signal.

© 1992 Optical Society of America