Ultra‐broadband luminescent sources that emit light over an extremely wide wavelength range are of great interest in the fields of photonics, medical treatment, and precision measurement. Extensive research has been conducted on materials doped with rare‐earth and transition‐metal ions, but the goal of fabricating an ultra‐broadband emitter has not been attained. We present a facile method to realize this kind of novel light source by stabilizing “active” centers (bismuth) in a “tolerant” host (nanoporous silica glass). The obtained highly transparent materials, in which, unusually, multiple bismuth centers (Bi+, Bi2+, and Bi3+) can be stabilized, emit in an ultra‐broadband wavelength range from blue‐green, orange, red, and white to the near‐infrared region. This tunable luminescence covers the spectral range of the traditional three primary colors (RGB) and also the telecommunications windows.

Bi-doped germanium silicate glass is prepared and their optical properties are investigated. The glass sample shows broadband and flat emission characteristics compared with germanate glass. The single-pass optical amplification was measured on a traditional two-wave mixing configuration. Ultrabroadband optical amplification at 1272 and 1560nm is observed simultaneously. The highest gain at 1272nm of germanium silicate glass reaches to 6.73dB excited with single commercially available 980nm laser diode. The glass is promising for optical amplification covering almost all the O, E, S, C, and L bands.

Oxyfluoride aluminosilicate glasses in the composition of 50SiO2–20Al2O3–20LiF–10GdF3–0.5TmF3–xYbF3 (x = 0, 1.0, 2.5, 5, 7.5, 10, 15, 20, 25 and 30 mol%) have been prepared to study their thermal and optical properties. From the differential thermal analysis measurements, glass transition temperatures and onset crystallization temperatures have been evaluated and from them glass stability factors were calculated. Glass stabilities decreased gradually with fluoride content increment in all the studied glasses. The photoluminescence and decay measurements have also been carried out for all these glasses. In these glasses, an efficient near infrared quantum cutting with optimal quantum efficiency approaching 187% has been demonstrated, by exploring the co-operative downconversion mechanism from Tm3+ to Yb3+, with 467 nm (Tm3+ : 3H6 → 1G4) excitation wavelength. These glasses are promising materials to achieve high efficiency silicon based solar cells by means of downconversion in the visible part of the solar spectrum.

Bi-doped sodium–potassium aluminosilicate glasses were synthesized and characterized. Broadband near-infrared (IR) emission covered the whole telecommunication wavelength region, with a maximum peak at about 1250 nm, a full width at half-maximum of about 370 nm, and a lifetime longer than 420 μs. The present glasses are potential materials for tunable lasers and optical amplifiers. The decrease of active Bi center concentration with the increase of Na2O content and the addition of CeO2are first reported here, and the IR emission center in sodium–potassium aluminosilicate glasses might be ascribed to low-valence-state bismuth, most probably, Bi+.

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