Molecular rovibrational dynamics investigated by two-photon wavepacket interferometry with phase-locked pulse pairs

Experimental arrangement of two-photon wavepacket interferometry. The femtosecond pulses are injected into a Michelson interferometer. One arm is varied in delay motor with 0.1 μm resolution, and the other arm is controlled by a piezoelectric transducer (PZT), and a monochromator is used to select about 1 cm−1 bandpass for the frequency locked. L1 and L2 is the lens, PMT is a photomultiplier tube, server circuit is for phase-locked loop (PLL).