Versatile femtosecond laser synchronization for multiple-timescale transient infrared spectroscopy 2.0

A versatile and easy-to-implement concept is presented, which allows one to time-synchronize in essence any amplified Ti:Sa laser system to a high-repetition rate Yb-laser system. The oscillator round trip frequency of one of the oscillators needs to be tunable by a few kHz only. That is, the repetition rates of the two laser oscillators do not have to be identical, rather synchronization is achieved only when the low-repetition rate Ti:Sa laser system produces a pump pulse. Piezoactuators for cavity length adjustment in the required range are a built-in option for modern high repetition rate laser systems, in which case no modification of the Ti:Sa laser system is required. Utilizing this synchronization, single-UV/VIS-pump–multiple IR-probe experiments become possible, covering a very wide range of timescales from 1 ps to 1 s with one-and-the-same instrument and with a time resolution of about 1 ps. Two example experiments are presented to demonstrate the capability of the setup.