Formation and measurement of molecular quantum picostructures

Using two laser pulses of femtosecond duration we excite a diatomic molecule (I₂) to a dissociative state where the wave function is localized around two internuclear separations. The structure of the wave function is controlled by the relative amplitude and the temporal separation of the exciting laser pulses. A delayed intense probe pulse measures the square of the wave function as a function of the internuclear separation |Ψ(R)|² by Coulomb exploding the molecule. We report a resolution of ∼2 Å in the internuclear range ∼6–15 Å. We discuss how intense femtosecond laser pulses provide a different approach to time-resolved photochemistry.