Ultrafast gain dynamics in N^+_2 lasing from highly excited vibrational states p

We experimentally demonstrate N^+_2 lasing actions at the wavelengths of 353.3, 353.8, and 354.9 nm using a circularly polarized femtosecond laser. The three laser lines correspond to the B2Σ+u(v'=5, 4, 3)->X2Σ+g(v'=4,3,2) transitions, respectively. Particularly, we reveal the pressure-dependent gai