Dopant and concentration dependence of linear and nonlinear refractive index and dispersion for new (Mg, Ba)F 2 based fluorophosphates glass

Abstract

Linear and nonlinear refractive index, Abbe number, electronic energy gap and oscillator strength are reported for a new series of (Mg, Ba)F 2 -based fluorophosphates glasses (MBBA system) doped with rare earth dopants (Er 3+ , Nd 3+ ) in the concentration range of 6.67×10 20 - 2.86×10 21 (ions/cm 3 ) and 2.5×10 20 - 1.25×10 21 (ions/cm 3 ), respectively. The linear refractive index is found to increase with increasing dopant concentration, while the Abbe number is found to be remarkably concentration invariant, i.e., around 66-68 for both dopants. The average electronic band gap is also found to be almost dopant concentration independent, i.e., about 4.1, while the electronic oscillator strength is found to slightly increase with increasing dopant concentration, i.e., from 6.2 to 6.4. The nonlinear refractive index is found to show a linear increase from 1.2866 to 1.4018 for the investigated dopant concentration range. Those results strongly suggest the present new series of glasses can be excellent laser hosts.