Z-scan technique to study gain properties of optically pumped media

The opportunity to study the optical gain properties of active media using the open aperture z-scan technique without an additional probe beam is demonstrated. The method allows for the evaluation of pump-induced photodynamic process parameters in UV solid-state active media on pumping and lasing wavelengths: excited-state absorption and photoionization cross-sections of active ions, effective absorption and ionization cross-sections of color centers and recombination rates. (letter)