research to applied industrial and social applications including but certainly not limited to window glasses, windscreens, kitchen cooktops, microscope and telescope lens, and optics, and so on, owing to such unmatched and outstanding properties as ease of large-scale and complex shape production as well as chemical and mechanical durability. [1] However, glasses, usually made by the traditional melt-quenching method viz., cooling a viscous liquid fast enough to avoid crystallization (known as supercooling), [2] are seriously constrained to those that entail an acceptable degree of glass-forming ability unless otherwise being made under extremely harsh conditions (e.g., superfast cooling or high-energy irradiation, etc.) that are not readily available to ordinary glass-making labs and factories. [3] This leads to a significantly limited range of available constituents and functions of the obtained glasses. For example, spectroscopic features of active dopants (e.g., rare-earth (REs) ions, transition, and main group metals) are closely associated with their chemical states and the surrounding chemical environments provided by the glass host; hence, it is possible to induce new photoluminescence (PL) functions such as ultrabroadband and enhanced up-/down-conversion emissions via proper doping, post thermal, and magnetic treatments or A new method is reported to achieve the manufacture of glass of arbitrary ratio of SiO 2 /P 2 O 5 which cannot be made by conventional melt-quenching method. The new method is termed "melt-in-melt" which encapsulates the key step in the glass manufacturing process, i.e. one molten glass is poured into another molten glass with a stirring at high temperatures. Because of near unlimited possibilities in designing new glass compositions, there is a correspondingly great degree of freedom in the topological engineering of the glass structure, which in turn strongly influences the photoluminescence (PL) properties of active dopants. As a proof concept, bismuth and erbium are selected as the indicator dopants for emphasizing the real advantages of the new method as an effective means to tailoring the PL properties of the doped glasses. The micro structure and element distribution within the fabricated glasses are comprehensively characterized by high-resolution scanning electron microscopy, micro-Raman and high-performance X-ray fluorescence spectroscopy. Phase separation occurring at both nano-and meso-scale is observed. Apart from the developed glasses being themselves promising broadband emission phosphors, the new glass-making method may extend the possible applications of glass for important photonic applications (e.g. optical sensing, lighting, display, optical amplification and lasing etc.).
