Abstract

Recently, we have shown that the nearly degenerate four-wave mixing (NDFWM) process can provide a direct and simultaneous measurement of the longitudinal (1/T₁) and transverse (1/T₂) relaxation rates of a resonant two-level atom. Furthermore, we observed that in the presence of buffer gases, the linewidth of the resonance describing the longitudinal relaxation process experiences a significant narrowing, belowo that of the natural width. Using a theoretical model, the narrowing was accounted for as arising from collisional effects in the ground-state population. ¹ These observations were made for the case where the radiation fields are co-polarized, and we concluded that NDFWM offers a unique technique for the measurement of the ground-state velocity-changing cross section.²

© 1984 Optical Society of America