Erbium-doped calcium barium phosphate glasses for 1.54 µm broadband optical amplifier

Abstract The Er 3+ -doped calcium barium phosphate glasses with chemical composition 30CaO:20BaO:(50-x)P 2 O 5 :xEr 2 O 3 (where x = 0.05, 0.10, 0.50, 1.00 and 2.00 mol%) were prepared by melt-quenching technique. The optical and NIR luminescence properties of the glass samples were investigated to determine the ability for using as broadband optical amplifier. The density, molar volume and refractive index were carried out. The absorption spectra showed 10 absorption bands corresponding to the transitions assigned by 4 I 15/2 → 4 G 11/2 (349 nm), 2 G 9/2 (403 nm), 4 F 5/2 (451 nm), 4 F 7/2 (488 nm), 2 H 11/2 (522 nm), 4 S 3/2 (544 nm), 4 F 9/2 (651 nm), 4 I 9/2 (803 nm), 4 I 11/2 (977 nm) and 4 I 13/2 (1537 nm). Judd-Ofelt analysis was applied in this work and found that the J-O parameters of the CaBaPEr20 glass are 7.44, 2.52 and 4.36 (x 10 -20 cm 2 ) for Ω 2 , Ω 4 and Ω 6 , respectively. Oscillator strength, radiative transition possibility, stimulated emission cross section and branching ratio were also evaluated. NIR luminescence spectra of the CaBaPEr20 glass under 977 nm excitation wavelength showed broad NIR emission band with the peak centered at 1541 nm (corresponding to 4 I 13/2 → 4 I 15/2 transition) in the range of 1455 to 1620 nm covers the S, C and L bands of optical amplifier. The gain bandwidth of optical amplifier calculated by the product of full width at half maximum and stimulated emission cross section was found to be 511 x 10 -28 cm 3 that relatively high compared with other Er 3+ -doped systems, indicated the present CaBaPEr20 glass ability for using as broadband optical amplifier at 1.54 µm. Excitation and emission spectra of the luminescence in visible region were also investigated in this work.