Enhanced linear and nonlinear optical properties of erbium/ytterbium lead phosphate glass by gamma irradiation for optoelectronics applications
O.I. Sallam, M. I. A. Abdel Maksoud, Said M. Kassem, A. S. Awed, N.A. Elalaily
Abstract
Abstract Herein, this study intends to reveal the impact of gamma irradiation on the structural, linear, and nonlinear optical characteristics of 47P 2 O 5 −23Na 2 O−6Al 2 O 3 −22PbO−0.5Er 2 O 3 −1.5Yb 2 O 3 glass. The Er/Yb-doped lead phosphate glass samples were produced using the traditional melt quenching procedure and then treated to different doses of gamma irradiation (0, 20, 50, and 100) kGy. The amorphous phase structure of the Er/Yb-doped lead phosphate glass samples was verified through XRD patterns. Also, the shift of the FTIR peaks due to the change in bond angles, and the change in the bond length of the P–O–P bridges means the glass network stability against radiation. With increasing irradiation dosages, the energy gap dropped from 4.11 eV to 3.42 eV and then enhanced to 3.48 at 100 kGy. At the same time, the Urbach energy enhanced from 10.23 eV to 37.03 eV. The oscillator energy Eo was found between 1.55 and 1.62 eV. Also, the dispersion energy E d varied between 2.11 eV at 100 kGy and 2.71 eV at the dose of 50 kGy. The percentage of free carrier ions to effective mass (N/m*) is in the range (4.82–8.66) × 10 47 cm 3 /g. Besides, the lattice dielectric constant ( $${\varepsilon }_{l}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>ε</mml:mi><mml:mi>l</mml:mi></mml:msub></mml:math> ) increased from 5.54 to 6.63 as the gamma dosages increased. Furthermore, increasing gamma doses up to 50 kGy promotes susceptibility, which subsequently declines at 100 kGy, suggesting that increasing gamma doses over 50 kGy weakens polarizability potential. While the increasing gamma doses up to 50 kGy reduces the nonlinear refractive index and then improves at 100 kGy. Overall, the nonlinear and linear research revealed that Er/Yb lead phosphate glass is being used as a promising material for gain media and optical amplifiers.