Mid-Infrared Amplified Spontaneous Emission From The F ' 0(G)(+) (D-1(2)) Ion-Pair State And Spectroscopic Characterization Of The Shallow 0(G)(+) (Ab) Valence State Of I-2

In this paper, we describe amplified spontaneous emission (ASE) from the f' 0(g)(+) (D-1(2)) ion-pair state of I-2 populated through a two-step laser excitation technique via the B (3)Pi(0(u)(+)) valence state. The intense infrared emission propagating in the direction of the incident laser beam is assigned to the ASE transition from the f' 0(g)(+) (D-1(2)) state to the F' 0(u)(+) (D-1(2)) ion-pair state. The subsequent ultraviolet fluorescence transition from the F' 0(u)(+) (D-1(2)) state to the 0(g)(+) (bb) state as well as the 0(g)(+) (ab) state is also reported. By Franck-Condon simulation of the cascading F' 0(u)(+) (D-1(2)) -> 0(g)(+) (bb) band, we determine the population distributions in the F' 0(u)(+) (D-1(2)) state generated by ASE, which are consistent with the intensity profile of the mid-infrared ASE spectrum. Finally, employing these vibrational distributions for the F' 0(u)(+) (D-1(2)) state, spectral parameters for the shallow 0(g)(+) (ab) state are derived.