We report a novel phenomenon in sodium-calcium-silicate glass doped with ${\mathrm{Ta}}^{5+}$ . Under irradiation with a $780\mathrm{nm}$ femtosecond pulsed laser, strong blue emission centered at about $420\mathrm{nm}$ could be observed. The spectral characteristics are similar to those pumped by ultraviolet photons. The log–log correlation between integrated emission intensity and pump power reveals that a two-photon absorption process is involved in the phenomenon. It is suggested that the presence of localized ${\mathrm{Ta}}^{5+}5d^0$ energy levels is responsible for the appearance of the blue emission. The results indicate that transition metal ions without d electrons play an important role in fields of optics when embedded into glass hosts.