Nonlinear optical coefficients of Samarium–activated lithium zinc borate glasses in femtosecond and nanosecond regimes

• Published in: Optics and laser technology 2024-01, Vol.168, p.109859, Article 109859
• Main Authors: Hanamar, Kavitha, Jagannath, G., Kolavekar, S.B., Ayachit, N.H., Patnala, Harika, Aloraini, Dalal Abdullah, Almuqrin, Aljawhara H., Sayyed, M.I., Pramod, A.G., Keshavamurthy, K., Venugopal Rao, S., Hegde, B.G.
• Format: Article
• Language: English
• Subjects: Femtosecond laser pulses; Glasses; Nanosecond laser pulses; Nonlinear optical; Rare earth ions; Z–scan
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2023.109859

•Efficacy of Sm2O3 on nonlinear optical properties of borate-based glass has been studied in nanosecond and femtosecond regimes.•The nonlinear optical properties are enhanced with addition of Sm2O3 to Li2O in the composition of the glass.•The nonlinear optical features are stronger under nanosecond pulse regime than those achieved at femtosecond regime.•The results indicate the lithium zinc borate glass bearing 5 mol% of Sm2O3 is useful for the nonlinear photonic functionalities. Influence of samarium trioxide on nonlinear optical (NLO) traits such as NLO absorption and refraction attributes of lithium zinc borate glasses has been investigated respectively using the open– and closed–aperture Z–scan techniques in visible and near–infrared spectral regions under nanosecond and femtosecond pulse regimes. The open–aperture Z–scan observations identified reverse saturable absorption and the mechanism responsible was two–photon absorption. The closed–aperture Z–scan depicted positive nonlinear refraction caused by the effect of self–focusing. There was an improvement in the NLO features with the increased samarium tri–oxide quantity in the composition thanks to non–bridging oxygens formation and the high polarizability of samarium ions. The NLO coefficients were more robust under nanosecond pulse excitation than those obtained under femtosecond excitation, attributed to the influence of excited state absorption and the two-photon absorption and thermal effects arising from longer pulse duration.