Direct measurements of 4I11/2 terminal-levellifetime in Nd:YLF

Direct measurements of the ⁴I_11/2 terminal-laser-level lifetime of Nd:YLF after saturating a pumped sample with an impulse-like pulse are reported. Measurements of small-signal gain recovery at the 1047- and 1053-nm laser wavelengths in four different samples, as well as transient excited-state absorption from the terminal laser level, provide consistent values for this lifetime that average 21.6 ns with subnanosecond accuracy