Rapid calculation of the efficiency of self-terminating four-level CI-switched lasers

We have developed a simple approach to deriving the efficiency of Q -switched four -level lasers, valid even for arbitrarily long lower laser level lifetimes. By eliminating time dependence from the calculation, numerical solutions can be obtained very rapidly. Its threshold and limiting slope efficiency values provide useful estimates for free -running pulsed four -level lasers as well as Q -switched. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement