## 1 Introduction  
Borate glass has been acknowledge as a good host for various rare-earth (RE) oxides among the traditional glass formers due to their strong glass formulation when compared with other conventional systems such as phosphates, germanates, vanadates and tellurite glass [1]. In addition, the glassy system is available easily, inexpensive, simple to prepare and a good host for a variety of elements [2]. The structural, physical, and optical characteristics of the glasses are greatly influenced by the composition and synthesis conditions. Therefore, to accomplish high emission efficiency, most of the glass system is activated using suitable transitional metals and/or rare-earth elements. The incorporation of rare-earth ions to the different glassy systems led to an improvement in the optical properties, such as refractive index, optical band gaps energy and laser amplification [3]. These improvements in optical properties for glassy systems drove them to be a potential candidate for lasers, solar concentrate systems, optical detectors, waveguides and telecommunications optical fibres [4]. Borate glasses have specific properties that make them beneficial for a wide technical application, but their chemical durability is relatively feeble, which limits their utility. Nevertheless, the addendum of oxides such as lithium oxide (Li\({}_{2}\)O) and aluminium oxide (Al\({}_{2}\)O\({}_{3}\)) can enhance the chemical durability and physical properties. Moreover, adding metal oxides as modifiers to the host matrix raises the radiative parameters. Besides, glasses containing metals minimize phonon energy and lead to an increase in the luminescence quantum from excited rare-earth ion states [5]. Therefore, glasses doped with rare-earth elements may be used because of their ion emission efficiencies of 4f-4f and 4f-5d. The 5s and 5p orbits provide shielding effects to electrons determined by 4f, which leads to significant RE spectral absorption and emission lines [6; 7]. Due to their unique characteristics, glass systems doped with rare-earth elements have been given considerable attention in recent decades. Furthermore, between all the RE ions, trivalent dysprosium (Dy\({}^{3+}\)) ions have been extensively investigated for the production of or improvement in optical amplification systems in telecommunication. It is important to study the luminescence of Dy\({}^{3+}\) ions in level \({}^{4}\)F\({}_{9/2}\) because it occurs in visible and NIR regions [8; 9]. Usually, transitions of Dy\({}^{3+}\) ion exhibit in yellow or blue regions of \({}^{4}\)F\({}_{9/2}\)\(\rightarrow\)\({}^{6}\)H\({}_{13/2}\) (electric dipole) and \({}^{4}\)F\({}_{9/2}\)\(\rightarrow\)\({}^{6}\)H\({}_{15/2}\) (magnetic dipole), respectively [10; 11]. It has been established that the transition of \({}^{4}\)F\({}_{9/2}\)\(\rightarrow\)\({}^{6}\)H\({}_{13/2}\) is hypersensitive, and therefore, its intensity depends heavily upon the existence of the host, while the intensity of transition of \({}^{4}\)F\({}_{9/2}\)\(\rightarrow\)\({}^{6}\)H\({}_{15/2}\) is not quite sensitive to host conditions. Dy\({}^{3+}\) has been acknowledged for its white light production, which is appropriate at an acceptable yellow to blue (Y/B) intensity ratio. Luminescent materials doped by Dy\({}^{3+}\) ions are therefore commonly used both in glasses and phosphors to generate white light [5; 6; 10]. Moreover, Dy\({}^{3+}\) ions have a various interesting characteristics such as high mechanical strength, high sensitivity and high thermal neutron absorption. They also can be utilized as the X-ray scintillators and as a yellow laser medium due to their intense yellow emission [12; 13; 14]. Unfortunately, there is limited information on the structure and physical properties of aluminium borate-bases doped with rare-earth ions, especially with Dy\({}^{3+}\) ion.