Rotationally-Resolved Two-Dimensional Infrared Spectroscopy of CO2(g): Rotational Wavepackets and Angular Momentum Transfer

Angular momentum transfer and wavepacket dynamics of CO2(g) were measured on the picosecond time scale using polarization-resolved two-dimensional infrared (2D-IR) spectroscopy. The dynamics of rotational levels up to J(max) similar to 50 are observed simultaneously at room temperature. Rotational wavepackets launched by the pump pulses cause oscillations in the intensity of individual peaks and beating patterns in the 2D-IR spectra. The structure of the rotationally resolved 2D-IR spectrum is explained using nonlinear response function theory. Spectral diffusion of the rotationally resolved 2D-IR peaks reveals information about angular momentum transfer. We demonstrate the ability to directly measure inelastic angular momentum dynamics simultaneously across the similar to 50 thermally excited rotational levels over several hundred picoseconds.

Automated summary

Angular momentum transfer and wavepacket dynamics of CO2(g) were measured on the picosecond time scale using polarization-resolved two-dimensional infrared (2D-IR) spectroscopy. Multiple rotational levels were observed simultaneously at room temperature, and the structure and spectral diffusion of the rotationally resolved 2D-IR spectrum were explained using nonlinear response function theory.