Tunable white light emitting glass suitable for long-wavelength ultraviolet excitation

► A novel Eu-Tb tunable white light emission oxide glass was prepared. ► The luminescences of the series of full-color emitting glasses were investigated. ► The energy transfer process of Tb3+→Eu3+ was confirmed. ► The Eu3+ ions were efficiently reduces to Eu2+ ions in glass melting by adjusting the reducing atmosphere.