Abstract: A composition includes: 30 mol % to 60 mol % SiO2; 15 mol % to 35 mol % Al2O3; 5 mol % to 25 mol % Y2O3; 0 mol % to 20 mol % TiO2; and 0 mol % to 25 mol % R2O, such that R2O is the sum of Na2O, K2O, Li2O, Rb2O, and Cs2O.

Abstract: A glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than about 0.7·t to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t) and a maximum central tension of less than about 71.5/?(t) (MPa). In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a point between the first surface and the second surface and increases from the point to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.

Abstract: Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than about 0.7·t up to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t) and a maximum central tension in the range from about 80 MPa to about 100 MPa. In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from the value to the second surface. The concentration of the metal oxide may be about 0.

Abstract: Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than about 0.7·t up to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t) and a maximum central tension in the range from about 80 MPa to about 100 MPa. In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from the value to the second surface. The concentration of the metal oxide may be about 0.

Abstract: A method of fabricating an optical fiber, the method including providing a core portion including a doped portion having greater than or equal to 1.6 wt. % of a halide dopant and eliminating seed precursor sites at an exterior surface of the core portion, the seed precursor sites forming seeds in the optical fiber, wherein the eliminating the seed precursor sites includes one or more of: (i) fabricating the core portion by densifying an exterior portion of a silica soot body prior to exposing the silica soot body to the halide dopant, and (ii) exposing the exterior surface of the core portion to a reactive etchant. The method further including forming an optical fiber preform by applying cladding material to the exterior surface of the core portion and drawing the fiber preform into the optical fiber.

Abstract: A glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than about 0.7·t to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t) and a maximum central tension of less than about 71.5/?(t) (MPa). In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a point between the first surface and the second surface and increases from the point to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.

Abstract: A thermally tempered aluminosilicate glass-ceramic composition includes a crystalline phase and a residual glass phase, wherein the two phases form a system wherein the thermal expansion curve of the system has two distinct sections diverging from an inflection point temperature in the range of about 450° C. to about 600° C., and wherein the difference between coefficient of thermal expansion of the glass-ceramic below and above the inflection point is greater than about 4 ppm/° C.

Abstract: A glass-based article may include from about 45 mol. % to about 80 mol. % SiO2; from about 0 mol. % to about 10 mol. % Na2O; less than about 5 mol. % K2O; a non-zero amount of Al2O; and. an amorphous phase and a crystalline phase. The article may further in include a stress profile comprising a surface compressive stress (CS) and a maximum central tension (CT). A ratio of Li2O (mol. %) to R2O (mol. %) in the article is from about 0.5 to about 1, where R2O is the sum of Li2O, Na2O, and K2O in the article. CT may be greater than or equal to about 50 MPa and less than about 100 MPa. CS may be greater than 2.0·CT. A depth of compression (DOC) of the stress profile may be greater than or equal to 0.14·t and less than or equal to 0.25·t, where t is the thickness of the article.

Abstract: A glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than about 0.7·t to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t) and a maximum central tension of less than about 71.5/?(t) (MPa). In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a point between the first surface and the second surface and increases from the point to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.

Abstract: A glass-based article may include from about 45 mol. % to about 80 mol. % SiO2; from about 0 mol. % to about 10 mol. % Na2O; less than about 5 mol. % K2O; a non-zero amount of Al2O; and an amorphous phase and a crystalline phase. The article may further in include a stress profile comprising a surface compressive stress (CS) and a maximum central tension (CT). A ratio of Li2O (mol. %) to R2O (mol. %) in the article is from about 0.5 to about 1, where R2O is the sum of Li2O, Na2O, and K2O in the article. CT may be greater than or equal to about 50 MPa and less than about 100 MPa. CS may be greater than 2.0·CT. A depth of compression (DOC) of the stress profile may be greater than or equal to 0.14·t and less than or equal to 0.25·t, where t is the thickness of the article.

Abstract: Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than 0.7·t, comprise a tangent that is less than about ?0.1 MPa/micrometers or greater than about 0.1 MPa/micrometers, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t). In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a point between the first surface and the second surface and increases from the point to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.5 mol % or greater throughout the thickness.

Abstract: Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than about 0.7·t up to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t) and a maximum central tension in the range from about 80 MPa to about 100 MPa. In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from the value to the second surface. The concentration of the metal oxide may be about 0.

Abstract: Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0·t up to 0.3·t and from greater than about 0.7·t up to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0·t to about 0.3·t) and a maximum central tension in the range from about 80 MPa to about 100 MPa. In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from the value to the second surface. The concentration of the metal oxide may be about 0.

Abstract: Embodiments of a filter for electromagnetic radiation are disclosed herein. The filter includes a first glass-ceramic substrate having a first refractive index, a second glass-ceramic substrate having the first refractive index, and a first region disposed between the first glass-ceramic substrate and the second glass-ceramic substrate. The first region has a second refractive index that is less than the first refractive index. Further, the second glass-ceramic substrate is arranged substantially parallel to and spatially disposed from the first glass-ceramic substrate. The filter transmits at least 70% of electromagnetic radiation within a band of frequencies and reflects at least 80% of electromagnetic radiation outside the band of frequencies. The band of frequencies is located within the frequency range of 20 GHz to 100 GHz.

Abstract: Embodiments of glass ceramic articles and precursor glasses are disclosed. In one or more embodiments, the glass-ceramic articles are transparent and include a nepheline phase and a phosphate phase. The glass-ceramic articles are colorless and exhibit a transmittance of about 70% or greater across the visible spectrum. The glass-ceramic articles may optionally include a lithium aluminosilicate phase. The crystals of the glass-ceramic articles may have a major cross-section of about 100 nm or less.

Abstract: A glass-based article may include from about 45 mol. % to about 80 mol. % SiO2; from about 0 mol. % to about 10 mol. % Na2O; less than about 5 mol. % K2O; a non-zero amount of Al2O; and an amorphous phase and a crystalline phase. The article may further in include a stress profile comprising a surface compressive stress (CS) and a maximum central tension (CT). A ratio of Li2O (mol. %) to R2O (mol. %) in the article is from about 0.5 to about 1, where R2O is the sum of Li2O, Na2O, and K2O in the article. CT may be greater than or equal to about 50 MPa and less than about 100 MPa. CS may be greater than 2.0·CT. A depth of compression (DOC) of the stress profile may be greater than or equal to 0.14·t and less than or equal to 0.25·t, where t is the thickness of the article.

Abstract: A transparent gahnite-spinel glass ceramic is provided. The glass ceramic includes a first crystal phase including (MgxZn1?x)Al2O4 where x is less than 1 and a second crystal phase including tetragonal ZrO2. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.

Abstract: A composition includes: 30 mol % to 60 mol % SiO2; 15 mol % to 35 mol % Al2O3; 5 mol % to 25 mol % Y2O3; 0 mol % to 20 mol % TiO2; and 0 mol % to 25 mol % R2O, such that R2O is the sum of Na2O, K2O, Li2O, Rb2O, and Cs2O.

Abstract: A glass-based article includes an amorphous phase and a crystalline phase, and a first surface and a second surface opposing the first surface thereby defining a thickness (t) of the glass-based article. The glass-based article has a stress profile with a surface compressive stress (CS) and a maximum central tension (CT). The maximum CT is greater than or equal to 80 MPa and less than or equal to 95 MPa, and the maximum CT is positioned within the glass-based article at a range from greater than or equal to 0.4·t and less than or equal to 0.6·t. The surface CS of the glass-based article is greater than or equal to 200 MPa; and a depth of compression (DOC) is from greater than or equal to 0.14·t and less than or equal to 0.25·t.

Abstract: A glass-based article may include from about 45 mol. % to about 80 mol. % SiO2; from about 0 mol. % to about 10 mol. % Na2O; less than about 5 mol. % K2O; a non-zero amount of Al2O; and an amorphous phase and a crystalline phase. The article may further in include a stress profile comprising a surface compressive stress (CS) and a maximum central tension (CT). A ratio of Li2O (mol. %) to R2O (mol. %) in the article is from about 0.5 to about 1, where R2O is the sum of Li2O, Na2O, and K2O in the article. CT may be greater than or equal to about 50 MPa and less than about 100 MPa. CS may be greater than 2.0·CT. A depth of compression (DOC) of the stress profile may be greater than or equal to 0.14·t and less than or equal to 0.25·t, where t is the thickness of the article.