An article comprising a luminescent nanoparticle is described, wherein the luminescent nanoparticle is selected from the group consisting of oxide nanoparticles, aluminate nanoparticles, and germanate nanoparticles; and wherein the luminescent nanoparticle is doped with one or more metals or rare-earth elements. A method of making a luminescent nanoparticle is also described, the method comprising the steps of: providing a nanoparticle, doping the nanoparticle with one or more chemical elements, heating the nanoparticle to a temperature of between about 1000° C. and about 1200° C. to alter the crystal structure of the nanoparticle and/or to create oxygen vacancies in the nanoparticle. A persistent luminescent nanoparticle is described, said persistent luminescent nanoparticle being selected from the group consisting of: LaAlO.sub.3 nanoparticles, Gd.sub.2O.sub.3 nanoparticles, SrAl.sub.2O.sub.4 nanoparticles, Y.sub.2O.sub.3 nanoparticles, and combinations thereof; wherein the nanoparticle is doped with about 1% or less of a chemical element selected from the group consisting of: holmium, europium, ytterbium, neodymium, magnesium, and combinations thereof.

A laser apparatus and a polycrystalline material are described. The apparatus includes the polycrystalline material which is configured to receive pumping light at a pump wavelength and to produce an optical gain for laser oscillation at a laser wavelength different from the pump wavelength. The polycrystalline material includes a ceramic material with a predetermined grain size. The polycrystalline material further includes a rare earth dopant with a predetermined concentration, wherein the predetermined grain size and the predetermined concentration cause the polycrystalline material to exhibit the optical gain at the laser wavelength.

A glass having from greater than or equal to about 0.1 mol. % to less than or equal to about 20 mol. % Ho.sub.2O.sub.3, and one or more chromophores selected from V, Cr, Mn, Fe, Co, Ni, Se, Pr, Nd, Er, Yb, and combinations thereof. The amount of Ho.sub.2O.sub.3 (mol. %) is greater than or equal to 0.7 (CeO.sub.2 (mol. %)+Pr.sub.2O.sub.3 (mol. %)+Er.sub.2O.sub.3 (mol. %)). The glass can include one or more fluorescent ions selected from Cu, Sn, Ce, Eu, Tb, Tm, and combinations thereof in addition to, or in place of the chromophores. The glass can also include multiple fluorescent ions.

This technology is directed to the preparation of doped-bismuth-silicate seed crystals through controlled crystallization (e.g. dimensionality of growth and nucleation mechanism) and the method of forming high purity single seed (particle size ranges from micrometers to millimeters) for various uses. These seed crystals have a nominal stoichiometry of Bi.sub.2-xA.sub.xSiO.sub.5, Bi.sub.2-xA.sub.xSi.sub.3O.sub.9, Bi.sub.4-xA.sub.xSi.sub.3O.sub.9, and Bi.sub.12-xA.sub.xSiO.sub.20, where A is a rare earth dopant selected from La, Ce, Nd, Pr, and/or Sm.

A glass having from greater than or equal to about 0.1 mol. % to less than or equal to about 20 mol. % Ho.sub.2O.sub.3, and one or more chromophores selected from V, Cr, Mn, Fe, Co, Ni, Se, Pr, Nd, Er, Yb, and combinations thereof. The amount of Ho.sub.2O.sub.3 (mol. %) is greater than or equal to 0.7(CeO.sub.2 (mol. %)+Pr.sub.2O.sub.3 (mol. %)+Er.sub.2O.sub.3 (mol. %)). The glass can include one or more fluorescent ions selected from Cu, Sn, Ce, Eu, Tb, Tm, and combinations thereof in addition to, or in place of the chromophores. The glass can also include multiple fluorescent ions.

Embodiments of the invention include a light source and a wavelength converting structure disposed in a path of light emitted by the light source. The wavelength converting structure includes a first phosphor that emits infrared light and a second phosphor that emits visible light. In some embodiments, the light source emits first light, the second phosphor absorbs the first light and emits second light, and the first phosphor absorbs the first light and emits third light and absorbs the second light and emits fourth light.

A nitride phosphor particle dispersion-type sialon ceramic of the present invention includes a matrix formed of a sialon-based compound; and at least one nitride phosphor which is dispersed in the matrix and contains a luminescence center element.

Embodiments of the invention include a light source and a wavelength converting structure disposed in a path of light emitted by the light source. The wavelength converting structure includes a first phosphor that emits infrared light and a second phosphor that emits visible light. In some embodiments, the light source emits first light, the second phosphor absorbs the first light and emits second light, and the first phosphor absorbs the first light and emits third light and absorbs the second light and emits fourth light.

A glass having from greater than or equal to about 0.1 mol. % to less than or equal to about 20 mol. % Ho.sub.2O.sub.3, and one or more chromophores selected from V, Cr, Mn, Fe, Co, Ni, Se, Pr, Nd, Er, Yb, and combinations thereof. The amount of Ho.sub.2O.sub.3 (mol. %) is greater than or equal to 0.7 (CeO.sub.2 (mol. %)+Pr.sub.2O.sub.3 (mol. %)+Er.sub.2O.sub.3 (mol. %)). The glass can include one or more fluorescent ions selected from Cu, Sn, Ce, Eu, Tb, Tm, and combinations thereof in addition to, or in place of the chromophores. The glass can also include multiple fluorescent ions.

An article comprising a luminescent nanoparticle is described, wherein the luminescent nanoparticle is selected from the group consisting of oxide nanoparticles, aluminate nanoparticles, and germanate nanoparticles; and wherein the luminescent nanoparticle is doped with one or more metals or rare-earth elements. A method of making a luminescent nanoparticle is also described, the method comprising the steps of: providing a nanoparticle, wherein the nanoparticle is doped with one or more chemical elements, and heating the nanoparticle to a temperature of between about 1000 C. and about 1200 C. to alter the crystal structure of the nanoparticle and/or to create oxygen vacancies in the nanoparticle. A persistent luminescent nanoparticle is described, said persistent luminescent nanoparticle being selected from the group consisting of: LaAlO.sub.3 nanoparticles, Gd.sub.2O.sub.3 nanoparticles, SrAl.sub.2O.sub.4 nanoparticles, Y.sub.2O.sub.3 nanoparticles, and combinations thereof; wherein the nanoparticle is doped with about 1 mol % or less of a chemical element selected from the group consisting of: holmium, europium, ytterbium, neodymium, magnesium, and combinations thereof.