Optical limiting of nanosecond duration laser pulses is demonstrated in lead galliate glasses. The dominant mechanism is thermally induced refractive index change with a small contribution from nonlinear absorption. Output fluences typically clamp about 5 µ J/cm 2 for blue laser pulses and ~ 20 µ J/cm 2 for red laser pulses, corresponding to optical densities of ~ 2.0. Effects of the addition of various traditional network formers ( SiO 2, GeO 2, and B 2 O 3) on the limiting are evaluated. Additionally, some material independent parameters associated with the optical limiting system are studied.
