Effect of Eu3+ in tuning the ultrafast third-order optical nonlinearity in heavy metal borate glasses

Abstract

Abstract Photonic vitreous materials with high optical nonlinearities and fast response times are beneficial for designing next generation nonlinear photonic devices. Herein, large concentration of heavy metal oxide (PbO and Bi2O3) containing borate glasses activated with different Eu3+ concentrations have been designed through the melt quench technique. The non-linear optical (NLO) attributes such as nonlinear optical absorption and refractions were ascertained by utilizing the open aperture (OA) and closed aperture (CA) Z-scan techniques respectively in the spectral regions of 750–1000 nm using femtosecond laser pulses. The OA and CA Z-scan profiles demonstrated a reverse saturable absorption (RSA) nonlinearity (ascribed to two-photon absorption) and a positive nonlinear refraction nonlinearity (attributed to self-focusing effect) respectively. The NLO coefficients such as α2, n2 and χ(3) values were improved with respect to Eu3+ content in the glasses composition due to non-bridging oxygen and hyperpolarizability of Eu3+ ions. The NLO studies suggested that the examined glasses could be constructive materials for NLO device utilizations in the near infrared spectral regime.