Stimulated emission and lasing in laser-induced plasma plume

• We studied stimulating emission and lazing in Al, Ga, In, Tl, Ge, Sn, Pb, Ca, Ti, Zr, Fe and Ni laser induced plasma.
• All LIP lasers described in this paper involve high absorption and emission transitions probabilities (≥107 s−1).
• Lasers based on LIP open opportunity to create coherent light sources in broad spectral range from UV up to NIR.

The lasing effect is demonstrated in laser plasmas induced on various metal targets and pumped by a laser tuned in resonance with a strong optical transition of a metal. The intense, polarized and low-divergent radiation is emitted from a longitudinally pumped plasma plume in forward and backward directions with respect to the pump beam. Lasing occurs only within duration of the pumping pulse. The effect is found for elements of 13th and 14th groups and for Ca, Ti, Zr, Fe and Ni. The Einstein coefficients for spontaneous emission of all lasing transitions are higher than 107 s−1. For some elements like Al and In, a three-level lasing scheme is realized. For others, like Tl, both three- and four-level lasing schemes are realized. It is found that the longitudinal pump geometry is more efficient than the transversal one.