Optical and visible and near-infrared fluorescence aspects of Er3+, Tm3+, and Nd3+-doped B2O3-rich glasses for fiber amplifiers and NIR lasers

Abstract

For synthesized each 1 mol% Er3+, Tm3+, and Nd3+-doped borate-rich glasses, optical and luminescence traits including fluorescence decay dynamics were explored. For Er3+: glass, at 1.4-1.65 mu m range a wide NIR (near-infrared) luminescence band centered at 1.531 mu m (I-4(13/2 & nbsp;)->& nbsp;I-4(15/2)) and in Tm3+: glass, at 1.35-1.6 mu m span a broad NIR fluorescence band centered at 1.458 mu m (H-3(4 & nbsp;)-> F-3(4)) are obtained by 980 nm LD (laser diode) pumping (I-4(15/2 & nbsp;)->& nbsp;I-4(11/2)) and 808 nm LD excitation (H-3(6 & nbsp;)-> H-3(4)) separately. Under 808 nm LD pumping (I-4(9/2 & nbsp;)->& nbsp;F-4(5/2)+H-2(9/2)), in Nd3+: glass, three emission bands peaked at 0.901 mu m (F-4(3/2 & nbsp;)->& nbsp;I-4(9/2)), 1.057 mu m (F-4(3/2 & nbsp;)->& nbsp;I-4(11/2)), and 1.329 mu m (F-4(3/2 & nbsp;)->& nbsp;I-4(13/2)) respectively are observed and in all such emissions, comparably the one obtained from transition F-4(3/2 & nbsp;)->& nbsp;I-4(11/2) is highly intense. For acquired main visible and NIR emissions, delta lambda(eff) (effective bandwidth), by Fuchtbauer-Ladenburg approach sigma(emi) (stimulated emission cross-section), gain bandwidth, and optical gain are evaluated. 75.73 nm, 113.67 nm, and 57.37 nm are the delta lambda(eff & nbsp;)values for Er3+: I-4(13/2 & nbsp;)->& nbsp;I-4(15/2), Tm3+: H-3(4 & nbsp;)-> F-3(4), and Nd3+: F-4(3/2 & nbsp;)-> I-4(13/2) transitions accordingly. Using McCumber's theory, the calculated peak sigma(emi) for Er3+: I-4(13/2 & nbsp;)->& nbsp;I-4(15/2) and Nd3+: F-4(3/2 & nbsp;)->& nbsp;I-4(9/2) transitions are 1.495 x 10-20 cm(2) and 0.5556 x 10-20 cm(2), respectively. I-4(13/2 & nbsp;)->& nbsp;I-4(15/2) transition gain cross-section spectra reveals C-band amplification at P (population inversion) = 50% in Er3+: glass, whereas at P = 30% for F-4(3/2 & nbsp;)->& nbsp;I-4(9/2) transition gain cross-section is positive for lasing action at-0.9 mm in Nd3+: glass. All analyzed NIR luminescence outcomes reveal that studied glasses could be potential gain media for C-, S-, and O-bands fiber amplifiers and solid-state lasers. (C)& nbsp;2022 The Author(s). Published by Elsevier B.V.& nbsp;