Absorption in neodimium glasses under powerful laser pulse propagation

Abstract A fast increase of the absorption at the wavelengths 0.66 and 1.053 μm is observed in Nd:glasses under powerful subnanosecond laser pulse self-focusing. The effect is explained by populating of the 4 I 1 1 2 levels of the Nd 3+ ions. The rate of absorption relaxation is τ≳10 -8 s.