Chinese Optics Letters, 2015, 13 (5): 050201, Published Online: Sep. 20, 2018
Ultrafast gain dynamics in N 2 + lasing from highly excited vibrational states pumped by circularly polarized femtosecond laser pulses
Abstract
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 B 2 Σ u + ( v ′ = 5,4 , 3 ) → X 2 Σ g + ( v = 4 , 3 , 2 ) transitions, respectively. Particularly, we reveal the pressure-dependent gain dynamics of these lasing actions from highly excited vibrational states with a pump–probe scheme. Our experimental results confirm that electron collisional excitation plays an important role in the establishment of a population inversion of N 2 + lasing at these wavelengths.
Kaixuan Zhai, Ziting Li, Hongqiang Xie, Chenrui Jing, Guihua Li, Bin Zeng, Wei Chu, Jielei Ni, Jinping Yao, Ya Cheng. Ultrafast gain dynamics in