Two-dimensional infrared spectroscopy of vibrational polaritons of molecules in an optical cavity.

Strong coupling of molecular vibrations to an infrared cavity mode affects their nature by creating dressed polariton states. We show how the single and double vibrational polariton manifolds may be controlled by varying the cavity coupling strength and probed by a time domain two-dimensional infrared (2DIR) technique, double quantum coherence. Applications are made to the amide-I (CO) and amide-II (CN) bond vibrations of N-methylacetamide.