The main goal of this paper is to present experimental results on compariso
n of lasing efficiency for Li III 13.5 nm (2-1 transition) line in LIF micr
ocapillary plasmas using 0.25 and 1 mu m subpicosecond pumping lasers, A fo
rmula for soft X-ray laser efficiency calculation is presented and used for
such comparisons. The results for discharge created preplasma in L = 4 mm
and L = 14 mm microcapillaries are also presented and compared with the res
ults for laser created preplasma.