Cascade generation in Al laser induced plasma

We found cascade IR generation in Al laser induced plasma. This generation includes doublet transitions 3s ²5s ²S_1/2→ 3s²4p ²P_1/2,3/2→ 3s²4s ²S_1/2; corresponding to strong lines at 2110 and 2117 nm, and much weaker lines at 1312–1315 nm. The 3s²5s²S _1/2 starting IR generation level is directly pumped from the 3s²3p ²P_3/2 ground level. The starting level for UV generation at 396.2 nm (transitions 3s²4s ²S_1/2→ 4p ²P_3/2) is populated due to the fast collisional processes in the plasma plume. These differences led to different time and special dependences on the lasing in the IR and UV spectral range within the aluminum laser induced plasma.