Detection limits for time-resolved coherent two-dimensional vibrational spectroscopy

Coherent two-dimensional vibrational spectroscopy is performed using doubly vibrationally enhanced four-wave mixing in dilute solutions of carbon disulfide using an ultrafast (< 1 ps) laser pulse system. The nonresonant electronic background and singly resonant coherent anti-Stokes Raman scattering contributions are suppressed by delaying the excitation pulses. With this suppression, we measured detection limits of 8 x 10(-5) M CS2 in bromo-chloromethane.