Experimental Observation Of Autler-Townes Splitting Of Li-2

Autler-Townes ( A-T) splitting of the A (1)Sigma(u)(+) state of Li-7'(2) has been experimentally studied by pulsed optical-optical double resonance (OODR) spectroscopy. A stronger coupling field ( the pump laser) excited an A (1)Sigma(u)(+) v', J' <-- X (1)Sigma(g)(+) v", J(u) transition and induced the A-T splitting of the A (1)Sigma(u)(+) v', J' and X (1)Sigma(g)(+) v(n), J(n) levels, while a detecting laser (the probe laser) detected the A-T splitting of the intermediate A (1Sigma)(+)(u) v', J' level by the further exciting to the 4 (1)Sigma(g)(+) state and monitored the collision-induced violet fluorescence from the upper 4 (1)Sigma(g)(+) level. When the coupling laser frequency was tuned off resonance, the excitation signals displayed doublet splitting which was proportional to the frequency detuning of the coupling laser under the experimental conditions. The dependence of relative intensities of the two lines on coupling and detecting laser intensities and buffer gas pressure was studied.