Nanosecond nonlinear optical, optical limiting and gamma radiation shielding attributes of Eu3+ ions doped heavy metal borate glasses

Abstract

Bismuth borate glasses activated with different Eu2O3 concentrations were synthesised by the traditional melt–quenching method. The efficacy of Eu3+ ions concentration on nanosecond third–order nonlinear optical, optical limiting and gamma radiation shielding attributes was systematically studied and discussed. The nonlinear optical and optical limiting features were studied at 532 nm excitation under nanosecond laser pulses using Z–scan technique. The two-photon absorption coefficient was enhanced from 1.55 × 10−11 to 2.37 × 10−11 m/W, the nonlinear refractive index was increased from 1.61 × 10−18 to 3.28 × 10−18 m2/W while the optical limiting threshold value was reduced from 2.451 × 109 to 0.292 × 109 J/m2 with increase in Eu2O3 concentration in the glass composition. This increase in two-photon absorption coefficient and decrease in optical limiting threshold values with respect to Eu3+ions clearly reveal the high Eu3+ containing (NBiBEu2 in the present investigation) glasses are beneficial for the construction of power optical limiters to work in visible (532 nm) spectral region under nanosecond regime. The radiation attenuation factors were determined between 0.276 and 1.275 MeV using Phy–X program. The linear attenuation coefficient (LAC) varied between 0.375 and 0.377 cm−1 at 0.276 MeV, and the maximum LAC was reported at this energy. With further increase in the energy, we found that the attenuation competence of the prepared glasses begins to weaken, and the lowest attenuation ability was found at 1.275 MeV. The effective atomic number (Zeff) was computed, and we found that the Zeff follows the order: NBiBEu2> NBiBEu1.5> NBiBEu1> NBiBEu0.5> NBiBEu0. The tenth value layer (TVL) for NBiBEu0 increases from 1.001 cm at 0.276 MeV, to 1.600 cm at 0.356 MeV, to 2.750 cm at 0.511 MeV and to 6.545 cm at 1.275 MeV.