Optical Properties of Mixed Alkali Borate Glasses

Abstract—In the present study glass samples of (40 – x)Li₂0 · xNa₂O · 10K₂O · 50B₂O₃ and (40 ‒ x)Li₂O · xK₂O · 10Na₂O · 50B₂O₃ (0 ≤ x ≤ 40 mol %) were prepared by melt quench technique. The cut-off wavelength varies non-linearly when Li₂O is replaced with Na₂O or K₂O. The type of electronic transition in the present glass systems is indirect allowed. Using single oscillator model, the oscillator energy E₀, the dispersion energy E_d, the static refractive index n₀, the oscillator strength S₀ and average oscillator wavelength λ₀ were determined. The ratio of free carrier concentration to the free carrier effective mass N_c/m*, the optical relaxation time τ and ε_∞ the high frequency dielectric constant were determined in the present glass systems. The real and imaginary parts of the optical conductivity dependence of energy in present glasses increases non-linearly with increasing photon energy.