Enhancement of rare earth ions hosting potential of B2O3 added germanium based glasses: A detailed optical analysis

Highlights: • GeSbNa:B novel glass system was developed by the conventional melt quenching method. • Energy band gap (E_g) values increased with the content of B₂O₃ (mol%). • E_d, n and S_o values enhanced with the increase of boron ions in the glass network. • Enhanced K value or optical conductivity of the glasses were observed. • Obtained low phonon energy (0.073–0.102 eV) in comparison to tellurite glasses. -- Abstract: Borate incorporated novel germanium based glass system was fabricated by traditional melt-quenching technique and is used as a probe for the generation of efficient lasers. In this context, we have explored in detail the impact of B₂O₃ addition on optical properties of GeSbNa (germanate-antimono-sodium) glass composition. The optical absorption spectra reveal that the cut-off edge of the glasses is shifted to lower wavelengths, due to smaller number of (NBO's) non-bridging oxygen atoms. Using optical energy band gap values, the phonon energy (E_Ω) of the glass system was calculated. Extinction coefficient (k) values were found to decrease in the wavelength range of 290–335 nm which is used for low loss optical devices. The refractive index (RI) of the glasses decreased, indicating that the entire B₂O₃ doped GeSbNa glass system obeys the normal dispersion mechanism. In addition, the boron mixed GeSbNa glass system shows low phonon energy, making it ideal for rare earth ion hosting glass systems for laser rods and promising candidate for manufacturing optical fibers.