| Nonlinear optical processes, with a particular emphasis on parametric four-wave mixing (PFWM), are studied in rubidium vapor. A theoretical framework is introduced that enables accurate calculations of nonlinear light-matter interactions, and calculations of these interactions using this framework are performed for a broad range of excitation conditions. In particular, the effects of femtosecond pulse parameters such as pulse duration, pulse energy, center wavelength, and chirp are investigated. Simulation results provide insight into the light-matter interactions in rubidium vapor for these conditions. The effects of pump pulse parameters on the production and evolution of atomic wavepackets in the nonlinear medium are investigated. A number of femtosecond-scale phenomena that were elusive or previously unknown are observed, including the observation of quantum beating at pump-probe time delays exceeding 500 ps, quantum beating on the 7s1/2 -- 5 d3/2 energy defect at 611 cm-1, and the effects of pump pulse chirp on the amplitude and temporal dynamics of quantum beating. Toward the goal of using the nonlinear optical process of PFWM to interrogate the nearest neighbor distribution (NND), a new analytical derivation for the NND in the non-interacting particle approximation is presented, along with the results of molecular dynamics simulations of the NND in rubidium vapor for realistic pair interaction potentials. |
