Glasses with high refractive index and low density

Abstract

A glass composition includes: from 35 mol.% to 62 mol.% TiO2; from 6 mol.% to 30 mol.% SiO2; from 1 mol.% to 30 mol.% BaO; and from 1 mol.% to 25 mol.% SrO. The glass composition is free or substantially-free of B2O3. The sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 47 mol.%. The sum of BaO, SrO, and CaO in the glass composition is from 20 mol.% to 50 mol.%. A total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%.

Description

SP24-098 GLASSES WITH HIGH REFRACTIVE INDEX AND LOW DENSITY

[0001] This Application claims the benefit of priority to U.S. Provisional Patent ApplicationSerial Number 63 / 636153 filed on April 19, 2024, the content of which is relied upon and incorporated herein by reference in its entirety. Field

[0002] The present specification generally relates to glass compositions and, in particular, to highrefractive index glass compositions having low density. Technical Background

[0003] Glass articles are a major component in augmented reality (AR) applications, servingvarious purposes to enable the immersive and visually enhanced experiences associated with AR. Generally, these glass articles are utilized to create compact and lightweight optical systems that enable the projection of virtual images into a user's field of view. How much light is bent or refracted as it passes through the glass articles depends on the refractive index of the glass. High refractive index glasses with low density allow for more efficient bending of light while reducing the size and weight of optical components. These properties are particularly significant in AR headsets, where comfort and portability may influence user adoption.

[0004] Accordingly, a continual need exists for glasses that have high refractive index and lowdensity. SUMMARY

[0005] According to a first aspect, A1, a glass composition may comprise: greater than or equalto 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%SP24-098

[0006] A second aspect A2 includes the glass composition according to the first aspect A1,wherein the glass composition is free or substantially-free of P2O5.

[0007] A third aspect A3 includes the glass composition according to either the first or secondaspects A1 or A2, wherein the glass composition comprises greater than or equal to 36 mol.% and less than or equal to 60 mol.% TiO2.

[0008] A fourth aspect A4 includes the glass composition according to any of the first throughthird aspects A1-A3, wherein the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 48 mol.%.

[0009] A fifth aspect A5 includes the glass composition according to any of the first throughfourth aspects A1-A4, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Nb2O3.

[0010] A sixth aspect A6 includes the glass composition according to any of the first through fifthaspects A1-A5, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Ta2O5.

[0011] A seventh aspect A7 includes the glass composition according to any of the first throughsixth aspects A1-A6, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Y2O3.

[0012] An eighth aspect A8 includes the glass composition according to any of the first throughseventh aspects A1-A7, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% ZrO2.

[0013] A ninth aspect A9 includes the glass composition according to any of the first througheighth aspects A1-A8, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% La2O3.

[0014] A tenth aspect A10 includes the glass composition according to any of the first throughninth aspects A1-A9, wherein RO is greater than 25 mol.% and less than or equal to 40 mol.%.SP24-098

[0015] An eleventh aspect A11 includes the glass composition according to any of the firstthrough tenth aspects A1-A10, wherein the glass composition comprises greater than or equal to 6 mol.% and less than or equal to 25 mol.% BaO.

[0016] A twelfth aspect A12 includes the glass composition according to any of the first througheleventh aspects A1-A11, wherein the glass composition comprises greater than or equal to 2 mol.% and less than or equal to 23 mol.% SrO.

[0017] A thirteenth aspect A13 includes the glass composition according to any of the firstthrough twelfth aspects A1-A12, wherein the glass composition comprises greater than 0 mol.% and less than or equal to 15 mol.% CaO.

[0018] A fourteenth aspect A14 includes the glass composition according to any of the firstthrough thirteenth aspects A1-A13, wherein the glass composition comprises greater than or equal to 10 mol.% and less than or equal to 23 mol.% SiO2.

[0019] A fifteenth aspect A15 includes the glass composition according to any of the first throughfourteenth aspects A1-A14, wherein the glass composition comprises: greater than or equal to 37 mol.% and less than or equal to 52 mol.% TiO2; greater than or equal to 18 mol.% and less than or equal to 23 mol.% SiO2; greater than or equal to 8 mol.% and less than or equal to 25 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 20 mol.% SrO.

[0020] According to a sixteenth aspect, A16, a glass article may comprise the glass compositionaccording to any of the first through fifteenth aspects A1-A15, wherein the glass article comprises: a refractive index (nd) at 589.3 nm greater than or equal to 1.97, and a density less than 4.8 g / cm3.

[0021] According to a seventeenth aspect, A17, a glass composition may comprise: greater thanor equal to 38 mol.% and less than or equal to 50 mol.% TiO2; greater than or equal to 19 mol.% and less than or equal to 22 mol.% SiO2; greater than or equal to 10 mol.% and less than or equal to 20 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 17 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 49 mol.%, RO is greater than or equal to 27 mol.% and less than or equal to 31 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and the sum of all oxide components is equal to 100 mol.%.SP24-098

[0022] An eighteenth aspect A18 includes the glass composition according to the seventeenthaspect A17, wherein the glass composition is free or substantially-free of P2O5.

[0023] A nineteenth aspect A19 includes the glass composition according to either theseventeenth or eighteenth aspects A17 or A18, wherein the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 50 mol.%.

[0024] A twentieth aspect A20 includes the glass composition according to any of the seventeenththrough nineteenth aspects A17-A19, wherein the glass article comprises greater than or equal to 0.1 mol.% and less than or equal to 10 mol.% Nb2O3.

[0025] A twenty-first aspect A21 includes the glass composition according to any of theseventeenth through twentieth aspects A17-A20, wherein the glass article comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% Ta2O5.

[0026] A twenty-second aspect A22 includes the glass composition according to any of theseventeenth through twenty-first aspects A17-A21, wherein the glass article comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% Y2O3.

[0027] A twenty-third aspect A23 includes the glass composition according to any of theseventeenth through twenty-second aspects A17-A22, wherein the glass article comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% ZrO2.

[0028] A twenty-fourth aspect A24 includes the glass composition according to any of theseventeenth through twenty-third aspects A17-A23, wherein the glass article comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% La2O3.

[0029] A twenty-fifth aspect A25 includes the glass composition according to any of theseventeenth through twenty-fourth aspects A17-A24, wherein RO is greater than 28 mol.% and less than or equal to 30 mol.%.

[0030] A twenty-sixth aspect A26 includes the glass composition according to any of theseventeenth through twenty-fifth aspects A17-A25, wherein the glass composition comprises greater than or equal to 46 mol.% and less than or equal to 50 mol.% TiO2.SP24-098

[0031] A twenty-seventh aspect A27 includes the glass composition according to any of theseventeenth through twenty-sixth aspects A17-A26, wherein the glass article comprises greater than or equal to 2 mol.% and less than or equal to 12 mol.% SrO.

[0032] A twenty-eighth aspect A28 includes the glass composition according to any of theseventeenth through twenty-seventh aspects A17-A27, wherein the glass article comprises greater than 0 mol.% and less than or equal to 10 mol.% CaO.

[0033] According to a twenty-ninth aspect, A29, a glass article may comprise the glasscomposition according to any of the first through fifteenth aspects A17-A28, wherein the glass article comprises: a refractive index (nd) at 589.3 nm greater than or equal to 1.970, and a density less than 4.8 g / cm3.

[0034] According to a thirtieth aspect, A30, a glass composition may comprise: greater than orequal to 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; and greater than 0 mol.% and less than 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%.

[0035] A thirty-first aspect A31 includes the glass composition according to the thirtieth aspectA30, wherein the glass composition is free or substantially-free of P2O5.

[0036] A thirty-second aspect A32 includes the glass composition according to either the thirtiethor thirty-first aspects A30 or A31, wherein the glass composition comprises greater than or equal to 36 mol.% and less than or equal to 60 mol.% TiO2.

[0037] A thirty-third aspect A33 includes the glass composition according to any of the thirtieththrough thirty-second aspects A30-A32, wherein the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 48 mol.%.SP24-098

[0038] A thirty-fourth aspect A34 includes the glass composition according to any of the thirtieththrough thirty-third aspects A30-A33, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Nb2O3.

[0039] A thirty-fifth aspect A35 includes the glass composition according to any of the thirtieththrough thirty-fourth aspects A30-A34, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Ta2O5.

[0040] A thirty-sixth aspect A36 includes the glass composition according to any of the thirtieththrough thirty-fifth aspects A30-A35, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Y2O3.

[0041] An thirty-seventh aspect A37 includes the glass composition according to any of thethirtieth through thirty-sixth aspects A30-A36, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% ZrO2.

[0042] A thirty-eighth aspect A38 includes the glass composition according to any of the thirtieththrough thirty-seventh aspects A30-A37, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% La2O3.

[0043] A thirty-ninth aspect A39 includes the glass composition according to any of the thirtieththrough thirty-eigthth aspects A30-A38, wherein the glass composition comprises greater than or equal to 1 mol.% and less than or equal to 8 mol.% B2O3.

[0044] An fortieth aspect A40 includes the glass composition according to any of the thirtieththrough thirty-ninth aspects A30-A39, wherein RO is greater than 25 mol.% and less than or equal to 40 mol.%.

[0045] A forty-first aspect A41 includes the glass composition according to any of the thirtieththrough fortieth aspects A30-A40, wherein the glass composition comprises greater than or equal to 6 mol.% and less than or equal to 25 mol.% BaO.

[0046] A forty-second aspect A42 includes the glass composition according to any of the thirtieththrough forty-first aspects A30-A41, wherein the glass composition comprises greater than or equal to 2 mol.% and less than or equal to 23 mol.% SrO.SP24-098

[0047] A forty-third aspect A43 includes the glass composition according to any of the thirtieththrough forty-second aspects A30-A42, wherein the glass composition comprises greater than 0 mol.% and less than or equal to 15 mol.% CaO.

[0048] A forty-fourth aspect A44 includes the glass composition according to any of the thirtieththrough forty-third aspects A30-A43, wherein the glass composition comprises greater than or equal to 10 mol.% and less than or equal to 25 mol.% SiO2.

[0049] According to a forty-fifth aspect, A45, a glass article may comprise the glass compositionaccording to any of the thirtieth through forty-fourth aspects A30-A44, wherein the glass composition comprises: greater than or equal to 37 mol.% and less than or equal to 52 mol.% TiO2; greater than or equal to 18 mol.% and less than or equal to 23 mol.% SiO2; greater than or equal to 8 mol.% and less than or equal to 25 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 20 mol.% SrO.

[0050] According to a forty-sixth aspect, A46, a glass article may comprise the glass compositionaccording to any of the thirtieth through forty-fifth aspects A30-A45, wherein the glass article comprises: a refractive index (nd) at 589.3 nm greater than or equal to 1.97, and a density less than 4.8 g / cm3.

[0051] According to a forty-seventh aspect, A47, a glass article may comprise: a glasscomposition comprising: greater than or equal to 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; greater than or equal to 0 mol.% and less than or equal to 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%, wherein the glass article comprises: an ultra-high refractive index (nd) at 589.3 nm greater than or equal to 2.05, and a density less than 4.8 g / cm3.SP24-098

[0052] Additional features and advantages of the glass compositions described herein will be setforth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the examples, and the claims.

[0053] It is to be understood that both the foregoing general description and the following detaileddescription describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG. 1 is a plan view of an electronic device incorporating any of the glass articlesaccording to one or more embodiments described herein; and

[0055] FIG. 2 is a perspective view of the electronic device of FIG. 1.DETAILED DESCRIPTION

[0056] Reference will now be made in detail to various embodiments of glass compositionshaving high refractive indices and low densities.

[0057] According to embodiments, a glass composition may comprise greater than or equal to 35mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than orequal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO. The glass composition is free or substantially-free of B2O3. A sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 47 mol.%. RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO. A total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%.

[0058] According to embodiments, a glass composition may comprise greater than or equal to 38mol.% and less than or equal to 50 mol.% TiO2; greater than or equal to 19 mol.% and less than or equal to 22 mol.% SiO2; greater than or equal to 10 mol.% and less than or equal to 20 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 17 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2,SP24-098 and La2O3 is greater than or equal to 49 mol.%, RO is greater than or equal to 27 mol.% and less than or equal to 31 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and the sum of all oxide components is equal to 100 mol.%.

[0059] According to embodiments, a glass composition may comprise greater than or equal to 35mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; and greater than or equal to 0 mol.% and less than 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%.

[0060] According to embodiments, a glass article may comprise a glass composition comprising:greater than or equal to 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; and greater than or equal to 0 mol.% and less than or equal to 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%, wherein the glass article comprises: an ultra-high refractive index (nd) at 589.3 nm greater than or equal to 2.05, and a density less than 4.8 g / cm3.

[0061] Various embodiments of glass compositions and glass articles formed therefrom will bedescribed herein with specific reference to the appended drawings.

[0062] Ranges may be expressed herein as from “about” one particular value, and / or to “about”another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.SP24-098

[0063] Directional terms as used herein - for example up, down, right, left, front, back, top,bottom - are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0064] Unless otherwise expressly stated, it is in no way intended that any method set forth hereinbe construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

[0065] As used herein, the singular forms “a,” “an” and “the” include plural referents unless thecontext clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0066] In the embodiments of the glass compositions and resultant glass articles described herein,the concentrations of constituent components (i.e., TiO2, SiO2, and the like) are specified in mole percent (mol.%) on an oxide basis, unless otherwise specified. A total sum of concentrations of oxide components in the glass composition is equal to 100 mol.

[0067] The term “substantially-free,” when used to describe the concentration and / or absence ofa particular constituent component in a glass composition and the resultant glass article, means that the constituent component is not intentionally added to the glass composition and the resultant glass article. However, the glass composition and the resultant glass article may contain traces of the constituent component as a contaminant or tramp in amounts of less than 0.05 weight percent (wt.%). As noted herein, the remainder of the application specifies the concentrations of constituent component in mol.%. The contaminant or tramp amounts of the constituentSP24-098 components are listed in wt.% for manufacturing purposes and one skilled in the art would understand the contaminant and tramp amounts being listed in wt.%.

[0068] The terms “0 mol.%” and “free,” when used to describe the concentration and / or absenceof a particular constituent component in a glass composition and the resultant glass article, means that the constituent component is not present in glass composition and the resultant glass article.

[0069] Refractive index, as described herein, is measured in accordance with ASTM E1967.Unless otherwise stated, refractive index as used herein means nd.

[0070] Density, as described herein, is measured by the buoyancy method of ASTM C693-93.

[0071] The elastic modulus (also referred to as Young’s modulus) of the glass composition, asdescribed herein, is provided in units of gigapascals (GPa) and is measured with Brillouin scattering, as described in the Examples herein, unless otherwise indicated.

[0072] The shear modulus of the glass composition, as described herein, is provided in units ofgigapascals (GPa). The shear modulus of the glass composition is measured with Brillouin scattering, as described in the Examples herein, unless otherwise indicated.

[0073] Poisson’s ratio, as described herein, is measured with Brillouin scattering, as described inthe Examples herein, unless otherwise indicated.

[0074] Conventional glass articles manufactured for AR applications may utilize boron oxide(B2O3). However, borate glasses including relatively high concentrations of B2O3 (e.g., greater than or equal to 10 mol.%) may have a relatively high density (e.g., greater than 4.8 g / cm3) due to the presence of higher-density components (e.g., Nb2O5, Ta2O5, and the like). A relatively high density may be undesirable for glass articles incorporated into AR headsets.

[0075] Disclosed herein are glass compositions and glass articles formed therefrom whichmitigate the aforementioned problems. Specifically, the glass compositions and the resultant glass articles disclosed herein are free, substantially-free, or contain a relatively low concentration (e.g., less than or equal to 10 mol.%) of boron oxide and comprise a relatively high concentration of TiO2 (i.e., greater than or equal to 35 mol.%), which results in glass compositions and resultantSP24-098 glass articles with relatively high refractive indices (i.e., greater than or equal to 1.97) and relatively low densities (i.e., less than 4.8 g / cm3).

[0076] The glass compositions and resultant glass articles described herein may be described astitanosilicate glass compositions and articles and comprise TiO2 and SiO2. The glass compositions and resultant glass articles described herein may also include index modifiers in addition to TiO2, such as Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3in a total concentration (i.e., a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3greater than or equal to 47 mol.%) sufficient to achieve a desired refractive index (i.e., greater than or equal to 1.97). The glass compositions and resultant glass articles described herein are free, substantially-free, or contain a relatively low concentration (e.g., less than or equal to 10 mol.%) of boron oxide and instead include TiO2. Borate glasses, including relatively high concentrations of B2O3 (e.g., greater than 10 mol.%) tend to include relatively higher concentrations of higher-density materials such as Nb2O5, La2O3, and / or WO3, leading to higher density glass. However, titanosilicate glass compositions, such as those described herein, have a lower concentration of the higher-density materials, thus leading to a decreased density of the glass compositions. The glass compositions and the resultant glass articles described herein also include alkaline earth oxides, such as BaO and SrO, in a total concentration of greater than or equal to 20 mol.% and less than or equal to 50 mol.% to stabilize the titanosilicate glass compositions described herein.

[0077] TiO2 is the primary glass former in the glass compositions described herein and may allowfor relatively low densities for the resulting glass article. It was unexpectedly found that higher concentrations of TiO2, in combination with other components described herein, did not crystallize, allowing for glass formation. The concentration of TiO2 in the glass compositions and resultant glass articles should be sufficiently high (i.e., greater than or equal to 35 mol.%) to provide high refractive indices (i.e., greater than or equal to 1.97). The amount of TiO2may be limited (i.e., less than or equal to 62 mol.%) to control the density of the glass composition, as the density of pure TiO2 or high TiO2 glasses is undesirably high. TiO2 may also provide resistance to solarization. Solarization or exposure to UV light may result in an undesired decrease in the transmittance of glass after irradiation with light in different wavelength regions.SP24-098

[0078] Accordingly, in embodiments, the glass composition and resultant glass article maycomprise greater than or equal to 35 mol.% and less than or equal to 62 mol.% TiO2. In embodiments, In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 36 mol.% and less than or equal to 60 mol.% TiO2. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 37 mol.% and less than or equal to 52 mol.% TiO2. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 38 mol.% and less than or equal to 50 mol.% TiO2. In embodiments, the glass composition and resultant glass article may comprise greater than orequal to 46 mol.% and less than or equal to 50 mol.% TiO2. .

[0079] In embodiments, the concentration of TiO2 in the glass composition and the resultant glassarticle may be greater than or equal to 35 mol.%, greater than or equal to 36 mol.%, greater than or equal to 37 mol.%, greater than or equal to 38 mol.%, or even greater than or equal to 40 mol.%. In embodiments, the concentration of TiO2in the glass composition and the resultant glass article may be less than or equal to 62 mol.%, less than or equal to 60 mol.%, less than or equal to 58 mol.%, less than or equal to 56 mol.%, less than or equal to 54 mol.%, less than or equal to 52 mol.%, less than or equal to 50 mol.%, or even less than or equal to 48 mol.%. In embodiments, the concentration of TiO2 in the glass composition and the resultant glass article may be greater than or equal to 35 mol.% and less than or equal to 62 mol.%, greater than or equal to 35 mol.% and less than or equal to 60 mol.%, greater than or equal to 35 mol.% and less than or equal to 58 mol.%, greater than or equal to 35 mol.% and less than or equal to 56 mol.%, greater than or equal to 35 mol.% and less than or equal to 54 mol.%, greater than or equal to 35 mol.% and less than or equal to 52 mol.%, greater than or equal to 35 mol.% and less than or equal to 50 mol.%, greater than or equal to 35 mol.% and less than or equal to 48 mol.%, greater than or equal to 36 mol.% and less than or equal to 62 mol.%, greater than or equal to 36 mol.% and less than or equal to 60 mol.%, greater than or equal to 36 mol.% and less than or equal to 58 mol.%, greater than or equal to 36 mol.% and less than or equal to 56 mol.%, greater than or equal to 36 mol.% and less than or equal to 54 mol.%, greater than or equal to 36 mol.% and less than or equal to 52 mol.%, greater than or equal to 36 mol.% and less than or equal to 50 mol.%, greater than or equal to 36 mol.% and less than or equal to 48 mol.%, greater than or equal to 38 mol.% and less than or equal to 62 mol.%, greater than or equal to 38 mol.% and less than or equal to 60 mol.%, greater than or equal to 38 mol.% and less than or equal to 58 mol.%, greater than or equal to 38 mol.% and less thanSP24-098 or equal to 56 mol.%, greater than or equal to 38 mol.% and less than or equal to 54 mol.%, greater than or equal to 38 mol.% and less than or equal to 52 mol.%, greater than or equal to 38 mol.% and less than or equal to 50 mol.%, greater than or equal to 38 mol.% and less than or equal to 48 mol.%, greater than or equal to 40 mol.% and less than or equal to 62 mol.%, greater than or equal to 40 mol.% and less than or equal to 60 mol.%, greater than or equal to 40 mol.% and less than or equal to 58 mol.%, greater than or equal to 40 mol.% and less than or equal to 56 mol.%, greater than or equal to 40 mol.% and less than or equal to 54 mol.%, greater than or equal to 40 mol.% and less than or equal to 52 mol.%, greater than or equal to 40 mol.% and less than or equal to 50 mol.%, or even greater than or equal to 40 mol.% and less than or equal to 48 mol.%, or any and all sub-ranges formed from any of these endpoints.

[0080] SiO2 is the secondary glass former in the glass compositions described herein and mayfunction to stabilize the network structure of the glass articles. The concentration of SiO2 in the glass compositions and resultant glass articles should be sufficiently high (i.e., greater than or equal to 6 mol.%) to provide some stabilization to the network structure of the resultant glass articles. The amount of SiO2may be limited (i.e., less than or equal to 30 mol.%) to control the melting point of the glass composition, as the melting temperature of pure SiO2 or high SiO2 glasses is undesirably high. Thus, limiting the concentration of SiO2 may aid in improving the meltability and the formability of the resulting glass article.

[0081] Accordingly, in embodiments, the glass composition and resultant glass article maycomprise greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 10 mol.% and less than or equal to 25 mol.% SiO2. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 18 mol.% and less than or equal to 23 mol.% SiO2. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 19 mol.% and less than or equal to 22 mol.% SiO2. In embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be greater than or equal to 6 mol.%, greater than or equal to 10 mol.%, greater than or equal to 15 mol.%, or even greater than or equal to 20 mol.%. In embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be less than or equal to 30 mol.%, less than or equal to 27 mol.%, less than or equal to 25 mol.%, less than or equal to 23 mol.%, or even less or equalSP24-098 to 21 mol.%. In embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be greater than or equal to 6 mol.% and less than or equal to 30 mol.%, greater than or equal to 6 mol.% and less than or equal to 27 mol.%, greater than or equal to 6 mol.% and less than or equal to 25 mol.%, greater than or equal to 6 mol.% and less than or equal to 23 mol.%, greater than or equal to 6 mol.% and less than or equal to 21 mol.%, greater than or equal to 10 mol.% and less than or equal to 30 mol.%, greater than or equal to 10 mol.% and less than or equal to 27 mol.%, greater than or equal to 10 mol.% and less than or equal to 25 mol.%, greater than or equal to 10 mol.% and less than or equal to 23 mol.%, greater than or equal to 10 mol.% and less than or equal to 21 mol.%, greater than or equal to 15 mol.% and less than or equal to 30 mol.%, greater than or equal to 15 mol.% and less than or equal to 27 mol.%, greater than or equal to 15 mol.% and less than or equal to 25 mol.%, greater than or equal to 15 mol.% and less than or equal to 23 mol.%, greater than or equal to 15 mol.% and less than or equal to 21 mol.%, greater than or equal to 20 mol.% and less than or equal to 30 mol.%, greater than or equal to 20 mol.% and less than or equal to 27 mol.%, greater than or equal to 20 mol.% and less than or equal to 25 mol.%, greater than or equal to 20 mol.% and less than or equal to 23 mol.%, or even greater than or equal to 20 mol.% and less than or equal to 21 mol.%, or any and all sub-ranges formed from any of these endpoints.

[0082] As described hereinabove, the glass compositions and the resultant glass article maycontain alkaline earth oxides (i.e., BaO and SrO) to further stabilize the glass composition and improve formability of the resultant glass article. The alkaline earth oxides are modifiers and do not participate in the glass network. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 1 mol.% and less than or equal to 30 mol.%. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 6 mol.% and less than or equal to 25 mol.%. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 8 mol.% and less than or equal to 25 mol.%. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 10 mol.% and less than or equal to 20 mol.%. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 1 mol.%, greater than or equal to 3 mol.%, greater than or equal to 6 mol.%, greater than or equal to 9 mol.%, greater than or equal to 12 mol.%, or even greater than or equal to 15 mol.%. InSP24-098 embodiments, the concentration of BaO in the glass composition and the resultant glass article may be less than or equal to 30 mol.%, less than or equal to 25 mol.%, less than or equal to 20 mol.%, or even less than or equal to 15 mol.%. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 1 mol.% and less than or equal to 30 mol.%, greater than or equal to 1 mol.% and less than or equal to 25 mol.%, greater than or equal to 1 mol.% and less than or equal to 20 mol.%, greater than or equal to 1 mol.% and less than or equal to 15 mol.%, greater than or equal to 3 mol.% and less than or equal to 30 mol.%, greater than or equal to 3 mol.% and less than or equal to 25 mol.%, greater than or equal to 3 mol.% and less than or equal to 20 mol.%, greater than or equal to 3 mol.% and less than or equal to 15 mol.%, greater than or equal to 6 mol.% and less than or equal to 30 mol.%, greater than or equal to 6 mol.% and less than or equal to 25 mol.%, greater than or equal to 6 mol.% and less than or equal to 20 mol.%, greater than or equal to 6 mol.% and less than or equal to 15 mol.%, greater than or equal to 9 mol.% and less than or equal to 30 mol.%, greater than or equal to 9 mol.% and less than or equal to 25 mol.%, greater than or equal to 9 mol.% and less than or equal to 20 mol.%, greater than or equal to 9 mol.% and less than or equal to 15 mol.%, greater than or equal to 12 mol.% and less than or equal to 30 mol.%, greater than or equal to 12 mol.% and less than or equal to 25 mol.%, greater than or equal to 12 mol.% and less than or equal to 20 mol.%, greater than or equal to 12 mol.% and less than or equal to 15 mol.%, greater than or equal to 15 mol.% and less than or equal to 30 mol.%, greater than or equal to 15 mol.% and less than or equal to 25 mol.%, or even greater than or equal to 15 mol.% and less than or equal to 20 mol.%, or any and all sub-ranges formed from any of these endpoints.

[0083] In embodiments, the concentration of SrO in the glass composition and the resultant glassarticle may be greater than or equal to 1 mol.% and less than or equal to 25 mol.%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be greater than or equal to 2 mol.% and less than or equal to 23 mol.%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be greater than or equal to 2 mol.% and less than or equal to 20 mol.%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be greater than or equal to 2 mol.% and less than or equal to 17 mol.%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be greater than or equal to 2 mol.% and less than or equal to 12 mol.%. In embodiments, the concentration of SrO in the glass composition and the resultant glass articleSP24-098 may be greater than or equal to 1 mol.%, greater than or equal to 2 mol.%, greater than or equal to 4 mol.%, greater than or equal to 6 mol.%, or even greater than or equal to 8 mol.%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be less than or equal to 25 mol.%, less than or equal to 20 mol.%, less than or equal to 15 mol.%, less than or equal to 10 mol.%, or even less than or equal to 5 mol.%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be greater than or equal to 1 mol.% and less than or equal to 25 mol.%, greater than or equal to 1 mol.% and less than or equal to 20 mol.%, greater than or equal to 1 mol.% and less than or equal to 15 mol.%, greater than or equal to 1 mol.% and less than or equal to 10 mol.%, greater than or equal to 1 mol.% and less than or equal to 5 mol.%, greater than or equal to 2 mol.% and less than or equal to 25 mol.%, greater than or equal to 2 mol.% and less than or equal to 20 mol.%, greater than or equal to 2 mol.% and less than or equal to 15 mol.%, greater than or equal to 2 mol.% and less than or equal to 10 mol.%, greater than or equal to 2 mol.% and less than or equal to 5 mol.%, greater than or equal to 4 mol.% and less than or equal to 25 mol.%, greater than or equal to 4 mol.% and less than or equal to 20 mol.%, greater than or equal to 4 mol.% and less than or equal to 15 mol.%, greater than or equal to 4 mol.% and less than or equal to 10 mol.%, greater than or equal to 4 mol.% and less than or equal to 5 mol.%, greater than or equal to 6 mol.% and less than or equal to 25 mol.%, greater than or equal to 6 mol.% and less than or equal to 20 mol.%, greater than or equal to 6 mol.% and less than or equal to 15 mol.%, greater than or equal to 6 mol.% and less than or equal to 10 mol.%, greater than or equal to 8 mol.% and less than or equal to 25 mol.%, greater than or equal to 8 mol.% and less than or equal to 20 mol.%, greater than or equal to 8 mol.% and less than or equal to 15 mol.%, greater than or equal to 8 mol.% and less than or equal to 10 mol.%, or any and all sub-ranges formed from any of these endpoints.

[0084] The glass compositions and result glass articles may further include CaO. Inembodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0 mol.% and less than or equal to 15 mol.% CaO. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0 mol.% and less than or equal to 10 mol.% CaO. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol.%, greater than or equal to 3 mol.%, greater than or equal to 5 mol.%, or even greater than or equal to 7 mol.%. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be less than orSP24-098 equal to 15 mol.%, less than or equal to 13 mol.%, less than or equal to 10 mol.%, less than or equal to 7 mol.%, or even less than or equal to 5 mol.%. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol.% and less than or equal to 15 mol.%, greater than or equal to 0 mol.% and less than or equal to 13 mol.%, greater than or equal to 0 mol.% and less than or equal to 10 mol.%, greater than or equal to 0 mol.% and less than or equal to 7 mol.%, greater than or equal to 0 mol.% and less than or equal to 5 mol.%, greater than or equal to 3 mol.% and less than or equal to 15 mol.%, greater than or equal to 3 mol.% and less than or equal to 13 mol.%, greater than or equal to 3 mol.% and less than or equal to 10 mol.%, greater than or equal to 3 mol.% and less than or equal to 7 mol.%, greater than or equal to 3 mol.% and less than or equal to 5 mol.%, greater than or equal to 5 mol.% and less than or equal to 15 mol.%, greater than or equal to 5 mol.% and less than or equal to 13 mol.%, greater than or equal to 5 mol.% and less than or equal to 10 mol.%, greater than or equal to 5 mol.% and less than or equal to 7 mol.%, greater than or equal to 7 mol.% and less than or equal to 15 mol.%, greater than or equal to 7 mol.% and less than or equal to 13 mol.%, or even greater than or equal to 7 mol.% and less than or equal to 10 mol.%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially-free of CaO.

[0085] RO is the sum (in mol.%) of BaO, SrO, and CaO present in the glass composition and theresultant glass article (i.e., RO = BaO (mol.%) + SrO (mol.%) + CaO (mol.%)). In embodiments, the concentration of RO in the glass composition and the resultant glass article may be greater than or equal to 20 mol.% and less than or equal to 50 mol.%. In embodiments, the concentration of RO in the glass composition and the resultant glass article may be greater than or equal to 25 mol.% and less than or equal to 40 mol.%. In embodiments, the concentration of RO in the glass composition and the resultant glass article may be greater than or equal to 27 mol.% and less than or equal to 31 mol.%. In embodiments, the concentration of RO in the glass composition and the resultant glass article may be greater than or equal to 28 mol.% and less than or equal to 30 mol.%. In embodiments, the concentration of RO in the glass composition and the resultant glass article may be greater than or equal to 20 mol.%, greater than or equal to 25 mol.%, greater than or equal to 27 mol.%, or even greater than or equal to 30 mol.%. In embodiments, the concentration of RO in the glass composition and the resultant glass article may be less than or equal to 50 mol.%, less than or equal to 45 mol.%, less than or equal to 40 mol.%, less than or equal to 35 mol.%, or evenSP24-098 less than or equal to 30 mol.%. In embodiments, the concentration of RO in the glass composition and the resultant glass article may be greater than or equal to 20 mol.% and less than or equal to 50 mol.%, greater than or equal to 20 mol.% and less than or equal to 45 mol.%, greater than or equal to 20 mol.% and less than or equal to 40 mol.%, greater than or equal to 20 mol.% and less than or equal to 35 mol.%, greater than or equal to 20 mol.% and less than or equal to 30 mol.%, greater than or equal to 25 mol.% and less than or equal to 50 mol.%, greater than or equal to 25 mol.% and less than or equal to 45 mol.%, greater than or equal to 25 mol.% and less than or equal to 40 mol.%, greater than or equal to 25 mol.% and less than or equal to 35 mol.%, greater than or equal to 25 mol.% and less than or equal to 30 mol.%, greater than or equal to 27 mol.% and less than or equal to 50 mol.%, greater than or equal to 27 mol.% and less than or equal to 45 mol.%, greater than or equal to 27 mol.% and less than or equal to 40 mol.%, greater than or equal to 27 mol.% and less than or equal to 35 mol.%, greater than or equal to 27 mol.% and less than or equal to 30 mol.%, greater than or equal to 30 mol.% and less than or equal to 50 mol.%, greater than or equal to 30 mol.% and less than or equal to 45 mol.%, greater than or equal to 30 mol.% and less than or equal to 40 mol.%, or even greater than or equal to 30 mol.% and less than or equal to 35 mol.%, or any and all sub-ranges formed from any of these endpoints.

[0086] The glass compositions and resultant glass articles described herein may also includeB2O3. In embodiments, where B2O3 is present, the B2O3 may act as a network modifier in the glass composition. As described herein, borate glasses including relatively high concentrations of B2O3 (e.g., greater than 10 mol.%) tend to include relatively higher concentrations of higher-density materials such as Nb2O5, La2O3, and / or WO3, leading to higher density glass. As such, the amount of B2O3included in the glass compositions and the resultant glass articles described herein may be limited (e.g., less than or equal to 10 mol.%). The glass composition and the resultant glass article may comprise greater than or equal to 0 mol.% and less than or equal to 10 mol.% B2O3. The glass composition and the resultant glass article may comprise greater than or equal to 1 mol.% and less than or equal to 8 mol.% B2O3. In embodiments, the concentration of B2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol.%, greater than or equal to 1 mol.%, greater than or equal to 3 mol.%, or even greater than or equal to 5 mol.%. In embodiments, the concentration of B2O3in the glass composition and the resultant glass article may be less than or equal to 10 mol.%, less than or equal to 8 mol.%, less than or equal to 6 mol.%, less than or equal to 4 mol.%, or even less than or equal to 2 mol.%. In embodiments, theSP24-098 concentration of B2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol.% and less than or equal to 10 mol.%, greater than or equal to 0 mol.% and less than or equal to 8 mol.%, greater than or equal to 0 mol.% and less than or equal to 6 mol.%, greater than or equal to 0 mol.% and less than or equal to 4 mol.%, greater than or equal to 0 mol.% and less than or equal to 2 mol.%, greater than or equal to 1 mol.% and less than or equal to 10 mol.%, greater than or equal to 1 mol.% and less than or equal to 8 mol.%, greater than or equal to 1 mol.% and less than or equal to 6 mol.%, greater than or equal to 1 mol.% and less than or equal to 4 mol.%, greater than or equal to 1 mol.% and less than or equal to 2 mol.%, greater than or equal to 3 mol.% and less than or equal to 10 mol.%, greater than or equal to 3 mol.% and less than or equal to 8 mol.%, greater than or equal to 3 mol.% and less than or equal to 6 mol.%, greater than or equal to 3 mol.% and less than or equal to 4 mol.%, greater than or equal to 5 mol.% and less than or equal to 10 mol.%, greater than or equal to 5 mol.% and less than or equal to 8 mol.%, or even greater than or equal to 5 mol.% and less than or equal to 6 mol.%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass compositions and the resultant glass articles described herein are free or substantially-free of B2O3.

[0087] The glass compositions and resultant glass articles described herein may also includeindex modifiers in addition to TiO2, such as Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3, to achieve a desired refractive index (i.e., greater than or equal to 1.97). Without being bound by any theory, it is believed that there may be a correlation between the amount of index modifiers in a given glass composition and the refractive index of the glass. For example, as described herein, the addition of index modifiers such as Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3to TiO2in an amount of at least 47 mol.% results in resultant glass article having a relatively high refractive index (i.e., greater than or equal to 1.97).

[0088] In embodiments, the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 in the glasscomposition and resultant glass article may be greater than or equal to 47 mol.%, greater than or equal to 48 mol.%, greater than or equal to 49 mol.%, or even greater than or equal to 50 mol.%. In embodiments, the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 in the glass composition and resultant glass article may be less than or equal to 70 mol.%, less than or equal to 65 mol.%, or even less than or equal to 60 mol.%. In embodiments, the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3in the glass composition and resultant glass article may be greater than or equalSP24-098 to 47 mol.% and less than or equal to 70 mol.%, greater than or equal to 47 mol.% and less than or equal to 65 mol.%, greater than or equal to 47 mol.% and less than or equal to 60 mol.%, greater than or equal to 48 mol.% and less than or equal to 70 mol.%, greater than or equal to 48 mol.% and less than or equal to 65 mol.%, greater than or equal to 48 mol.% and less than or equal to 60 mol.%, greater than or equal to 49 mol.% and less than or equal to 70 mol.%, greater than or equal to 49 mol.% and less than or equal to 65 mol.%, greater than or equal to 49 mol.% and less than or equal to 60 mol.%, greater than or equal to 50 mol.% and less than or equal to 70 mol.%, greater than or equal to 50 mol.% and less than or equal to 65 mol.%, or even greater than or equal to 50 mol.% and less than or equal to 60 mol.%, or any and all sub-ranges formed from any of these endpoints.

[0089] In embodiments, the concentration of Nb2O3 in the glass composition and the resultantglass article may be greater than or equal to 0.1 mol.% and less than or equal to 12 mol.%. In embodiments, the concentration of Nb2O3in the glass composition and the resultant glass article may be greater than or equal to 0.1 mol.% and less than or equal to 10 mol.%. In embodiments, the concentration of Nb2O3in the glass composition and the resultant glass article may be greater than or equal to 0 mol.%, greater than or equal to 0.1 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1 mol.%, greater than or equal to 3 mol.%, or even greater than or equal to 5 mol.%. In embodiments, the concentration of Nb2O3 in the glass composition and the resultant glass article may be less than or equal to 12 mol.%, less than or equal to 10 mol.%, less than or equal to 8 mol.%, or even less than or equal to 6 mol.%. In embodiments, the concentration of Nb2O3in the glass composition and the resultant glass article may be greater than or equal to 0 mol.% and less than or equal to 12 mol.%, greater than or equal to 0 mol.% and less than or equal to 10 mol.%, greater than or equal to 0 mol.% and less than or equal to 8 mol.%, greater than or equal to 0 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 6 mol.%, greater than or equal to 1 mol.% and less than or equal to 12 mol.%, greater than or equal to 1 mol.% and less than or equal to 10 mol.%, greater than or equal to 1SP24-098 mol.% and less than or equal to 8 mol.%, greater than or equal to 1 mol.% and less than or equal to 6 mol.%, greater than or equal to 3 mol.% and less than or equal to 12 mol.%, greater than or equal to 3 mol.% and less than or equal to 10 mol.%, greater than or equal to 3 mol.% and less than or equal to 8 mol.%, greater than or equal to 3 mol.% and less than or equal to 6 mol.%, greater than or equal to 5 mol.% and less than or equal to 12 mol.%, greater than or equal to 5 mol.% and less than or equal to 10 mol.%, greater than or equal to 5 mol.% and less than or equal to 8 mol.%, or even greater than or equal to 5 mol.% and less than or equal to 6 mol.%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially-free of Nb2O3.

[0090] In embodiments, the glass composition and the resultant glass article may comprisegreater than or equal to 0 mol.% and less than or equal to 12 mol.% Ta2O5. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% Ta2O5. In embodiments, the concentration of Ta2O5in the glass composition and the resultant glass article may be greater than or equal to 0 mol.%, greater than or equal to 0.1 mol.%, greater than or equal to 0.5 mol.%, or even greater than or equal to 1 mol.%. In embodiments, the concentration of Ta2O5 in the glass composition and the resultant glass article may be less than or equal to 12 mol.%, less than or equal to 10 mol.%, less than or equal to 8 mol.%, less than or equal to 6 mol.%, less than or equal to 4 mol.%, or even less than or equal to 2 mol.%. In embodiments, the concentration of Ta2O5 in the glass composition and the resultant glass article may be greater than or equal to 0 mol.% and less than or equal to 12 mol.%, greater than or equal to 0 mol.% and less than or equal to 10 mol.%, greater than or equal to 0 mol.% and less than or equal to 8 mol.%, greater than or equal to 0 mol.% and less than or equal to 6 mol.%, greater than or equal to 0 mol.% and less than or equal to 4 mol.%, greater than or equal to 0 mol.% and less than or equal to 2 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 4 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 2 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.5 mol.% and less thanSP24-098 or equal to 4 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 2 mol.%, greater than or equal to 1 mol.% and less than or equal to 12 mol.%, greater than or equal to 1 mol.% and less than or equal to 10 mol.%, greater than or equal to 1 mol.% and less than or equal to 8 mol.%, greater than or equal to 1 mol.% and less than or equal to 6 mol.%, greater than or equal to 1 mol.% and less than or equal to 4 mol.%, or even greater than or equal to 1 mol.% and less than or equal to 2 mol.%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially-free of Ta2O5.

[0091] In embodiments, the glass composition and the resultant glass article may comprisegreater than or equal to 0 mol.% and less than or equal to 12 mol.% Y2O3. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% Y2O3. In embodiments, the concentration of Y2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol.%, greater than or equal to 0.1 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1 mol.%, or even greater than or equal to 2 mol.%. In embodiments, the concentration of Y2O3in the glass composition and the resultant glass article may be less than or equal to 12 mol.%, less than or equal to 10 mol.%, less than or equal to 8 mol.%, less than or equal to 6 mol.%, or even less than or equal to 4 mol.%. In embodiments, the concentration of Y2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol.% and less than or equal to 12 mol.%, greater than or equal to 0 mol.% and less than or equal to 10 mol.%, greater than or equal to 0 mol.% and less than or equal to 8 mol.%, greater than or equal to 0 mol.% and less than or equal to 6 mol.%, greater than or equal to 0 mol.% and less than or equal to 4 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 4 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 4 mol.%, greater than or equal to 1 mol.% and less than or equal to 12 mol.%, greater than or equal to 1 mol.% and less than or equal to 10 mol.%, greater than or equal to 1 mol.% and less than or equal to 8 mol.%, greater than or equal to 1 mol.% and less than or equal to 6 mol.%, greater than orSP24-098 equal to 1 mol.% and less than or equal to 4 mol.%, greater than or equal to 2 mol.% and less than or equal to 12 mol.%, greater than or equal to 2 mol.% and less than or equal to 10 mol.%, greater than or equal to 2 mol.% and less than or equal to 8 mol.%, greater than or equal to 2 mol.% and less than or equal to 6 mol.%, or even greater than or equal to 2 mol.% and less than or equal to 4 mol.%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially-free of Y2O3.

[0092] In embodiments, the glass composition and the resultant glass article may comprisegreater than or equal to 0 mol.% and less than or equal to 12 mol.% ZrO2. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% ZrO2. In embodiments, the concentration of ZrO2 in the glass composition and the resultant glass article may be greater than or equal to 0 mol.%, greater than or equal to 0.1 mol.%, or even greater than or equal to 0.5 mol.%. In embodiments, the concentration of ZrO2in the glass composition and the resultant glass article may be less than or equal to 12 mol.%, less than or equal to 10 mol.%, less than or equal to 8 mol.%, less than or equal to 6 mol.%, or even less than or equal to 4 mol.%. In embodiments, the concentration of ZrO2in the glass composition and the resultant glass article may be greater than or equal to 0 mol.% and less than or equal to 12 mol.%, greater than or equal to 0 mol.% and less than or equal to 10 mol.%, greater than or equal to 0 mol.% and less than or equal to 8 mol.%, greater than or equal to 0 mol.% and less than or equal to 6 mol.%, greater than or equal to 0 mol.% and less than or equal to 4 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 4 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 6 mol.%, or even greater than or equal to 0.5 mol.% and less than or equal to 4 mol.%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially- free of ZrO2.SP24-098

[0093] In embodiments, the glass composition and the resultant glass article may comprisegreater than or equal to 0 mol.% and less than or equal to 12 mol.% La2O3. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% La2O3. In embodiments, the concentration of La2O3in the glass composition and the resultant glass article may be greater than or equal to 0 mol.%, greater than or equal to 0.1 mol.%, greater than or equal to 0.5 mol.%, or even greater than or equal to 1 mol.%. In embodiments, the concentration of La2O3 in the glass composition and the resultant glass article may be less than or equal to 12 mol.%, less than or equal to 10 mol.%, less than or equal to 8 mol.%, less than or equal to 6 mol.%, less than or equal to 4 mol.%, or even less than or equal to 2 mol.%. In embodiments, the concentration of La2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol.% and less than or equal to 12 mol.%, greater than or equal to 0 mol.% and less than or equal to 10 mol.%, greater than or equal to 0 mol.% and less than or equal to 8 mol.%, greater than or equal to 0 mol.% and less than or equal to 6 mol.%, greater than or equal to 0 mol.% and less than or equal to 4 mol.%, greater than or equal to 0 mol.% and less than or equal to 2 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 4 mol.%, greater than or equal to 0.1 mol.% and less than or equal to 2 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 12 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 10 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 8 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 6 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 4 mol.%, greater than or equal to 0.5 mol.% and less than or equal to 2 mol.%, greater than or equal to 1 mol.% and less than or equal to 12 mol.%, greater than or equal to 1 mol.% and less than or equal to 10 mol.%, greater than or equal to 1 mol.% and less than or equal to 8 mol.%, greater than or equal to 1 mol.% and less than or equal to 6 mol.%, greater than or equal to 1 mol.% and less than or equal to 4 mol.%, or even greater than or equal to 1 mol.% and less than or equal to 2 mol.%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially-free of La2O3.

[0094] The glass compositions and the resultant glass articles described herein may be free orsubstantially-free of P2O5.SP24-098

[0095] In embodiments, the glass composition may comprise: greater than or equal to 35 mol.%and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%

[0096] In embodiments, the glass composition may comprise: greater than or equal to 45 mol.%and less than or equal to 50 mol.% TiO2; greater than or equal to 19 mol.% and less than or equal to 22 mol.% SiO2; greater than or equal to 10 mol.% and less than or equal to 20 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 17 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 49 mol.%, RO is greater than or equal to 27 mol.% and less than or equal to 31 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and the sum of all oxide components is equal to 100 mol.%.

[0097] In embodiments, the glass composition may comprise: greater than or equal to 38 mol.%and less than or equal to 50 mol.% TiO2; greater than or equal to 19 mol.% and less than or equal to 22 mol.% SiO2; greater than or equal to 10 mol.% and less than or equal to 20 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 17 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 49 mol.%, RO is greater than or equal to 27 mol.% and less than or equal to 31 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and the sum of all oxide components is equal to 100 mol.%.

[0098] In embodiments, the glass composition may comprise: greater than or equal to 35 mol.%and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; and greater than or equal to 0 mol.% and less than or equal to 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3,SP24-098 ZrO2, and La2O3 is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%.

[0099] The articles formed from the glass compositions described herein may be any suitableshape or thickness, which may vary depending on the particular application for use of the glass composition. Glass sheet embodiments may have a thickness greater than or equal to 30 µm, greater than or equal to 50 µm, greater than or equal to 100 µm, greater than or equal to 250 µm, greater than or equal to 500 µm, greater than or equal to 750 µm, or even greater than or equal to 1 mm. In embodiments, the glass sheet embodiments may have a thickness less than or equal to 6 mm, less than or equal to 5 mm, less than or equal to 4 mm, less than or equal to 3 mm, or even less than or equal to 2 mm. In embodiments, the glass sheet embodiments may have a thickness greater than or equal to 30 µm and less than or equal to 6 mm, greater than or equal to 30 µm and less than or equal to 5 mm, greater than or equal to 30 µm and less than or equal to 4 mm, greater than or equal to 30 µm and less than or equal to 3 mm, greater than or equal to 30 µm and less than or equal to 2 mm, greater than or equal to 50 µm and less than or equal to 6 mm, greater than or equal to 50 µm and less than or equal to 5 mm, greater than or equal to 50 µm and less than or equal to 4 mm, greater than or equal to 50 µm and less than or equal to 3 mm, greater than or equal to 50 µm and less than or equal to 2 mm, greater than or equal to 100 µm and less than or equal to 6 mm, greater than or equal to 100 µm and less than or equal to 5 mm, greater than or equal to 100 µm and less than or equal to 4 mm, greater than or equal to 100 µm and less than or equal to 3 mm, greater than or equal to 100 µm and less than or equal to 2 mm, greater than or equal to 250 µm and less than or equal to 6 mm, greater than or equal to 250 µm and less than or equal to 5 mm, greater than or equal to 250 µm and less than or equal to 4 mm, greater than or equal to 250 µm and less than or equal to 3 mm, greater than or equal to 250 µm and less than or equal to 2 mm, greater than or equal to 500 µm and less than or equal to 6 mm, greater than or equal to 500 µm and less than or equal to 5 mm, greater than or equal to 500 µm and less than or equal to 4 mm, greater than or equal to 500 µm and less than or equal to 3 mm, greater than or equal to 500 µm and less than or equal to 2 mm, greater than or equal to 750 µm and less than or equal to 6 mm, greater than or equal to 750 µm and less than or equal to 5 mm, greater than or equal to 750 µm and less than or equal to 4 mm, greater than or equal to 750 µm and less than or equal to 3 mm, greater than or equal to 750 µm and less than or equal to 2 mm, greater than or equal to 1 mmSP24-098 and less than or equal to 6 mm, greater than or equal to 1 mm and less than or equal to 5 mm, greater than or equal to 1 mm and less than or equal to 4 mm, greater than or equal to 1 mm and less than or equal to 3 mm, or even greater than or equal to 1 mm and less than or equal to 2 mm, or any and all sub-ranges formed from any of these endpoints.

[0100] In embodiments, the glass compositions and resultant glass articles may have a relativelyhigh refractive index (i.e., greater than or equal 1.97). The refractive index of a glass is a measure of how much light slows down and bends as it passes through the glass, compared to its speed and direction in a vacuum. A relatively high refractive index means that light slows down and bends more significantly as it enters and passes through the glass. As disclosed herein, high refractive indices may be desirable in applications such as AR where efficient bending of light is important. In embodiments, the glass compositions and the resultant glass articles may have a refractive index greater than or equal to 1.97. In embodiments, the glass compositions and resultant glass articles may have an ultra-high refractive index (i.e., greater than or equal to 2.05). In embodiments, the glass composition and the resultant glass article may have a refractive index greater than or equal to 1.97, greater than or equal to 1.98, greater than or equal to 2.00, greater than or equal to 2.03, greater than or equal to 2.05, greater than or equal to 2.07 or even greater than or equal to 2.10.

[0101] In embodiments, the glass composition and the resultant glass article may have a densityless than or equal to 4.80 g / cm3. In embodiments, the glass composition and the resultant glass article may have a density less than or equal to 4.70 g / cm3. The density of glass is a measure of glass contained in a given volume. A relatively high density means that more mass is packed into a small volume, whereas a low density glass will have less mass in the same volume. As disclosed herein, low density glasses may be desirable in applications such as AR where comfort and weight may influence user adoption. In embodiments, the glass composition and the resultant glass article may have a density greater than or equal to 3.75 g / cm3, greater than or equal to 3.80 g / cm3, greater than or equal to 3.85 g / cm3, greater than or equal to 3.90 g / cm3, or even greater than or equal to 3.95 g / cm3. In embodiments, the glass composition and the resultant glass article may have a density less than or equal to 4.80 g / cm3, less than or equal to 4.70 g / cm3, less than or equal to 4.60 g / cm3, less than or equal to 4.50 g / cm3, less than or equal to 4.40 g / cm3, less than or equal to 4.30 g / cm3, or even less than or equal to 4.20 g / cm3. In embodiments, the glass composition and the resultant glass article may have a density greater than or equal to 3.75 g / cm3and less than or equalSP24-098 to 4.80 g / cm3, greater than or equal to 3.75 g / cm3and less than or equal to 4.70 g / cm3, greater than or equal to 3.75 g / cm3and less than or equal to 4.60 g / cm3, greater than or equal to 3.75 g / cm3and less than or equal to 4.50 g / cm3, greater than or equal to 3.75 g / cm3and less than or equal to 4.40 g / cm3, greater than or equal to 3.75 g / cm3and less than or equal to 4.30 g / cm3, greater than or equal to 3.75 g / cm3and less than or equal to 4.20 g / cm3, greater than or equal to 3.80 g / cm3and less than or equal to 4.80 g / cm3, greater than or equal to 3.80 g / cm3and less than or equal to 4.70 g / cm3, greater than or equal to 3.80 g / cm3and less than or equal to 4.60 g / cm3, greater than or equal to 3.80 g / cm3and less than or equal to 4.50 g / cm3, greater than or equal to 3.80 g / cm3and less than or equal to 4.40 g / cm3, greater than or equal to 3.80 g / cm3and less than or equal to 4.30 g / cm3, greater than or equal to 3.80 g / cm3and less than or equal to 4.20 g / cm3, greater than or equal to 3.85 g / cm3and less than or equal to 4.80 g / cm3, greater than or equal to 3.85 g / cm3and less than or equal to 4.70 g / cm3, greater than or equal to 3.85 g / cm3and less than or equal to 4.60 g / cm3, greater than or equal to 3.85 g / cm3and less than or equal to 4.50 g / cm3, greater than or equal to 3.85 g / cm3and less than or equal to 4.40 g / cm3, greater than or equal to 3.85 g / cm3and less than or equal to 4.30 g / cm3, greater than or equal to 3.85 g / cm3and less than or equal to 4.20 g / cm3, greater than or equal to 3.90 g / cm3and less than or equal to 4.80 g / cm3, greater than or equal to 3.90 g / cm3and less than or equal to 4.70 g / cm3, greater than or equal to 3.90 g / cm3and less than or equal to 4.60 g / cm3, greater than or equal to 3.90 g / cm3and less than or equal to 4.50 g / cm3, greater than or equal to 3.90 g / cm3and less than or equal to 4.40 g / cm3, greater than or equal to 3.90 g / cm3and less than or equal to 4.30 g / cm3, greater than or equal to 3.90 g / cm3and less than or equal to 4.20 g / cm3, greater than or equal to 3.95 g / cm3and less than or equal to 4.80 g / cm3, greater than or equal to 3.95 g / cm3and less than or equal to 4.70 g / cm3, greater than or equal to 3.95 g / cm3and less than or equal to 4.60 g / cm3, greater than or equal to 3.95 g / cm3and less than or equal to 4.50 g / cm3, greater than or equal to 3.95 g / cm3and less than or equal to 4.40 g / cm3, greater than or equal to 3.95 g / cm3and less than or equal to 4.30 g / cm3, or even greater than or equal to 3.95 g / cm3and less than or equal to 4.20 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[00102] It was unexpectedly found that the glass compositions having an ultra-high refractiveindex (i.e., greater than or equal to 2.05), according to the embodiments disclosed herein, still have densities that fall into the above ranges for density. Conventional ultra-high refractive index glasses may have relatively higher densities, such as densities greater than 4.8 g / cm3. TheSP24-098 combination of ultra-high refractive index and lower-density properties in a single glass composition may be desirable in applications such as lightweight optical devices, high- performance lenses, and other technologies where both optical performance and light weight considerations are desired.

[0103] As discussed hereinabove, the glass compositions and the resultant glass articlesdescribed herein may have a relatively high refractive index and a relatively low density such that the glass compositions and the resultant glass articles are suitable for AR headsets. Additionally, the glass compositions and the resultant glass articles described herein may have high rigidity. These properties are reflected in the relatively high Young’s modulus (i.e., greater than or equal to 100 GPa), shear modulus (i.e., greater than or equal to 40 GPa), and Poisson’s Ratio (i.e., greater than or equal to 0.28). Without being bound by any theory, it is believed that the glass compositions’ relatively high amount of index modifiers (i.e., Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3to TiO2in an amount of at least 47 mol.%) result in high rigidity, as these components correlate with higher moduli. Additionally, glass compositions containing B2O3and P2O5may be more likely to be brittle and exhibit low fracture toughness. As the glass compositions herein contain little to no amounts of B2O3 and may be free or substantially-free of P2O5, the glass compositions herein have higher fracture toughness.

[0104] In embodiments, the glass composition and the resultant glass article may have a Young’smodulus greater than or equal to 90 GPa, greater than or equal to 95 GPa, greater than or equal to 100 GPa, greater than or equal to 105 GPa, or even greater than or equal to 110 GPa. In embodiments, the glass composition and the resultant glass article may have a Young’s modulus less than or equal to 150 GPa, less than or equal to 140 GPa, or even less than or equal to 130 GPa. In embodiments, the glass composition and the resultant glass article may have a Young’s modulus greater than or equal to 90 GPa and less than or equal to 150 GPa, greater than or equal to 90 GPa and less than or equal to 140 GPa, greater than or equal to 90 GPa and less than or equal to 130 GPa, greater than or equal to 95 GPa and less than or equal to 150 GPa, greater than or equal to 95 GPa and less than or equal to 140 GPa, greater than or equal to 95 GPa and less than or equal to 130 GPa, greater than or equal to 100 GPa and less than or equal to 150 GPa, greater than or equal to 100 GPa and less than or equal to 140 GPa, greater than or equal to 100 GPa and less than or equal to 130 GPa, greater than or equal to 105 GPa and less than or equal to 150 GPa, greater thanSP24-098 or equal to 105 GPa and less than or equal to 140 GPa, greater than or equal to 105 GPa and less than or equal to 130 GPa, greater than or equal to 110 GPa and less than or equal to 150 GPa, greater than or equal to 110 GPa and less than or equal to 140 GPa, or even greater than or equal to 110 GPa and less than or equal to 130 GPa, or any and all sub-ranges formed from any of these endpoints.

[0105] In embodiments, the glass composition and the resultant glass article may have a shearmodulus greater than or equal to 30, greater than or equal to 35 GPa, or even greater than or equal to 40 GPa. In embodiments, the glass composition and the resultant glass article may have a shear modulus less than or equal to 60 GPa, less than or equal to 55 GPa, or even less than or equal to 50 GPa. In embodiments, the glass composition and the resultant glass article may have a shear modulus greater than or equal to 30 GPa and less than or equal to 60 GPa, greater than or equal to 30 GPa and less than or equal to 55 GPa, greater than or equal to 30 GPa and less than or equal to 50 GPa, greater than or equal to 35 GPa and less than or equal to 60 GPa, greater than or equal to 35 GPa and less than or equal to 55 GPa, greater than or equal to 35 GPa and less than or equal to 50 GPa, greater than or equal to 40 GPa and less than or equal to 60 GPa, greater than or equal to 40 GPa and less than or equal to 55 GPa, or even greater than or equal to 40 GPa and less than or equal to 50 GPa, or any and all sub-ranges formed from any of these endpoints.

[0106] In embodiments, the glass compositions and the resultant glass articles described hereinmay have a relatively high Poisson’s ratio, which increases the fracture energy such that the glass compositions are more resistant to damage. In embodiments, the glass composition and the resultant glass article may have a Poisson’s ratio greater than or equal to 0.26, greater than or equal to 0.27, or even greater than or equal to 0.28. In embodiments, the glass composition and the resultant glass article may have a Poisson’s ratio less than or equal to 0.31, less than or equal to 0.30, or even less than or equal to 0.29. In embodiments, the glass composition and the resultant glass article may have a Poisson’s ratio greater than or equal to 0.26 and less than or equal to 0.31, greater than or equal to 0.26 and less than or equal to 0.30, greater than or equal to 0.26 and less than or equal to 0.29, greater than or equal to 0.27 and less than or equal to 0.31, greater than or equal to 0.26 and less than or equal to 0.30, greater than or equal to 0.26 and less than or equal to 0.29, greater than or equal to 0.27 and less than or equal to 0.31, greater than or equal to 0.27 andSP24-098 less than or equal to 0.30, or even greater than or equal to 0.27 and less than or equal to 0.29, or any and all sub-ranges formed from any of these endpoints.

[0107] In embodiments, a glass article may comprise: a glass composition comprising: greaterthan or equal to 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; and greater than or equal to 0 mol.% and less than or equal to 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%, wherein the glass article comprises: an ultra-high refractive index (nd) at 589.3 nm greater than or equal to 2.05, and a density less than 4.8 g / cm3.

[0108] In embodiments, the process for making a glass article includes heat treating the glasscomposition as described herein at one or more preselected temperatures for one or more preselected times to melt the glass composition and cooling the glass composition. In embodiments, the heat treatment for making a glass article may include (i) heating a batch of theglass composition at a rate of 1-100 °C / min to glass melting temperature; (ii) maintaining the batchof the glass composition at the glass melting temperature for a time greater than or equal to 4 hours and less than or equal to 100 hours to produce a glass precursor article; and (iii) cooling the formed glass precursor article to room temperature to form a glass article. In embodiments, the glassmelting temperature may be greater than or equal to 1500 °C and less than or equal to 1700 °C.

[0109] The glass compositions and resultant glass articles described herein may be used for avariety of applications including, for example, for AR headsets. Other applications may use the glass compositions and resultant glass articles described herein, including, for example, LCD and LED displays, computer monitors, and automated teller machines (ATMs); for touch screen or touch sensor applications, for portable electronic devices including, for example, mobile telephones, personal media players, watches and tablet computers; for integrated circuit applications including, for example, semiconductor wafers; for photovoltaic applications; for architectural glass applications; for automotive or vehicular glass applications; or for commercialSP24-098 or household appliance applications. In embodiments, a consumer electronic device (i.e., smartphones, tablet computers, watches, personal computers, ultrabooks, televisions, and cameras), an architectural glass, and / or an automotive glass may comprise a glass article as described herein.

[0110] An exemplary electronic device incorporating any of the glass articles disclosed herein isshown in FIGS. 1 and 2. Specifically, FIGS. 1 and 2 show a consumer electronic device 100 including a housing 102 conformed to be placed over an individual’s eyes and having a nose cutout 104, lenses 106, and side shields 108. Electrical components (not shown) that are at least partially inside or entirely within the housing and including at least a controller, a memory, and displays at or adjacent to the lenses 106. An individual’s eyes align with the lenses 106 and displays 110. In embodiments, the lenses 106 may include any of the glass articles disclosed herein. Examples

[0111] In order that various embodiments be more readily understood, reference is made to thefollowing examples, which are intended to illustrate various embodiments of the glass compositions described herein.

[0112] Tables 1 and 2 show example glass compositions and comparative glass compositions(in terms of mol.%) and the respective properties of the glass compositions. Glass articles are formed having the examples glass compositions E1-E82 and comparative glass compositions C1- C8. The mechanical properties (i.e., Young’s modulus, shear modulus, and Poisson’s ratio) of Examples E1-E79 and comparative glass compositions C1-C8 were measured using Brillouin scattering (BRS).

[0113] BRS is measured using a tandem interferometer at 90 degrees and 532 nm excitation.The Brilluoin frequency shift lies in GHz frequency range and is related to material parameters and angle between excitation and scattering beam as: Δƒ = (2 n sin φ / 2)V / λo,where n is refractive index, V is speed of sound, φ is angle between excitation and scattering beams, is wavelength of light. Both longitudinal and transverse peaks are typically observedSP24-098 in solid materials, which allows for both longitudinal and transverse speeds of sound. When the angle is 180 degrees, one cannot observe transverse peaks, but the signal is very large and may be used in the test for better accuracy. Speed of sound is related to mechanical properties and density of the material. Using Brilluoin spectroscopy and knowing density, the speed of sound may be obtained and all major mechanical properties of the material such as Young’s modulus, shear modulus, and Poisson ratio may be derived therefrom.

[0114] Table 1E1 E2 E3 E4 E5 E6 E750.00 50.00 50.00 50.00 50.00 48.64 48.5820.00 20.00 20.00 22.54 22.58 20.00 20.0018.91 14.23 14.58 12.45 18.58 10.14 10.145.00 10.10 5.00 14.97 8.99 10.00 10.006.09 5.68 10.42 - - 9.86 9.86- - - - - 1.36 -- - - - - - 1.42- - - - - - -- - - - - - -- - - - - - -100.00 100.00 100.00 100.00 100.00 100.00 100.0030.00 30.01 30.00 27.42 27.57 30.00 30.0050.00 50.00 50.00 50.00 50.00 50.00 50.002.012 2.011 2.020 2.007 2.003 2.010 2.0104.125 4.099 3.996 4.084 4.156 3.999 3.986112.1 115.2 116.5 114.2 113.9 118.4 118.043.5 44.7 45.2 44.4 44.3 45.9 45.80.289 0.288 0.289 0.286 0.287 0.291 0.289

[0115] Table 1 cont.Example E8 E9 E10 E11 E12 E13 E14TiO2 45.00 46.53 46.45 47.74 46.49 46.51 45.00SP24-098 E8 E9 E10 E11 E12 E13 E1420.00 20.02 20.00 20.00 20.00 20.00 20.0010.14 18.93 10.14 10.14 10.14 10.14 10.1410.00 6.01 10.00 10.00 10.00 10.00 10.009.86 5.00 9.86 9.86 9.86 9.86 9.86- - - - - - -5.00 - 3.55 - - - -- 2.30 - - 2.28 1.30 1.49- 1.21 - 2.26 1.23 2.19 3.51- - - - - - -100.00 100.00 100.00 100.00 100.00 100.00 100.0030.00 29.94 30.00 30.00 30.00 30.00 30.0050.00 50.04 50.00 50.00 50.00 50.00 50.00 2.005 2.006 2.002 2.014 2.001 2.010 2.0164.065 4.388 4.039 4.198 4.240 4.301 4.413118.8 122.6 118.5 123.2 118.5 119.7 122.646.1 47.5 46.0 47.8 45.9 46.4 47.50.289 0.289 0.287 0.289 0.292 0.290 0.289

[0116] Table 1 cont.Example E15 E16 E17 E18 E19 E20 E21TiO250.00 50.00 50.00 50.00 50.00 50.00 46.50 SiO2 20.00 20.71 21.22 21.74 22.42 20.00 20.00BaO 14.58 15.75 16.61 17.45 18.58 14.58 14.58SrO 5.00 6.16 7.01 7.86 9.00 5.00 5.00CaO 10.42 7.38 5.16 2.95 - 10.42 10.42Y2O3 - - - - - - -ZrO2 - - - - - - -La2O3 - - - - - - -Ta2O5 - - - - - - -Nb2O3, - - - - - - 3.50SP24-098 E15 E16 E17 E18 E19 E20 E21100.00 100.00 100.00 100.00 100.00 100.00 100.0030.00 29.29 28.78 28.26 27.58 30.00 30.0050.00 50.00 50.00 50.00 50.00 50.00 50.00 2.021 2.009 2.011 1.998 2.001 2.020 2.0304.014 4.077 4.09 4.137 4.15 4.008 4.072117.0 114.7 111.7 111.5 111.4 114.6 116.345.4 44.6 43.4 43.3 43.3 44.5 45.20.288 0.287 0.288 0.287 0.286 0.289 0.286

[0117] Table 1 cont.SP24-098

[0118] Table 1 cont.E29 E30 E31 E32 E33 E34 E3540.64 40.61 45.00 40.42 40.51 45.00 40.56 20.00 17.60 15.45 20.00 17.49 15.60 20.0010.14 10.14 19.00 19.00 19.00 10.14 10.1410.00 10.00 5.00 5.00 5.00 10.00 10.009.86 9.86 6.00 6.00 6.00 9.86 9.862.42 2.42 - - - 1.10 1.112.58 2.58 - - - 5.00 5.00- - - - - 1.10 1.11- - 5.00 5.00 5.00 1.10 1.114.36 6.79 4.55 4.58 7.00 1.10 1.11100.00 100.00 100.00 100.00 100.00 100.00 100.0030.00 30.00 30.00 30.00 30.00 30.00 30.0050.00 52.40 54.55 50.00 52.51 54.40 50.00 2.020 2.050 2.070 2.050 2.080 2.040 2.0104.145 4.257 4.755 4.646 4.743 4.431 4.299122.4 123.1 123.2 118.8 97.3 124.9 120.447.6 47.8 47.7 46.2 38.1 48.4 46.70.286 0.288 0.293 0.286 0.279 0.291 0.288

[0119] Table 1 cont.Example E36 E37 E38 E39 E40 E41 E42TiO245.00 42.50 40.59 38.36 48.58 48.58 46.18 SiO2 13.36 15.62 17.53 20.00 20.00 17.71 20.00BaO 10.14 10.14 10.14 10.14 10.14 10.14 10.14SrO 10.00 10.00 10.00 10.00 10.00 10.00 10.00CaO 9.86 9.86 9.86 9.86 9.86 9.86 9.86Y2O3 1.66 1.72 1.72 1.66 - - -ZrO2 5.00 5.00 5.00 5.00 1.42 1.42 1.42SP24-098 E36 E37 E38 E39 E40 E41 E421.66 1.72 1.72 1.66 - - -1.66 1.72 1.72 1.66 - - -1.66 1.72 1.72 1.66 - 2.29 2.40100.00 100.00 100.00 100.00 100.00 100.00 100.0030.00 30.00 30.00 30.00 30.00 30.00 30.0056.64 54.38 52.47 50.00 50.00 52.29 50.00 2.060 2.040 2.020 2.010 2.027 2.048 2.0294.541 4.462 4.464 4.421 4.026 4.057 4.041125.6 122.1 123.8 121.7 117.7 120.7 118.048.5 47.3 48.0 47.1 45.7 46.8 45.80.294 0.291 0.291 0.291 0.288 0.289 0.288

[0120] Table 1 cont.SP24-098 Example E43 E44 E45 E46 E47 E48 E49Young's Modulus (GPa) 120.2 119.2 121.9 119.8 119.9 118.8 118.9Shear Modulus (GPa) 46.7 46.3 47.4 46.5 46.5 46.2 46.1Poisson's Ratio 0.286 0.289 0.287 0.287 0.288 0.285 0.288

[0121] Table 1 cont.E50 E51 E52 E53 E54 E55 E5646.60 46.40 43.69 43.40 40.35 39.89 45.00 20.00 20.00 20.00 20.00 20.00 20.00 13.4214.58 12.89 14.58 11.50 14.58 12.79 10.145.00 4.28 5.00 3.68 5.00 4.23 10.0010.42 12.82 10.42 14.82 10.42 12.98 9.860.68 0.72 1.26 1.32 1.93 2.02 -- - - - - - 5.000.68 0.72 1.26 1.32 1.93 2.02 -0.68 0.72 1.26 1.32 1.93 2.02 -1.36 1.45 2.53 2.64 3.86 4.05 6.58100.00 100.00 100.00 100.00 100.00 100.00 100.0030.00 29.99 30.00 30.00 30.00 30.00 30.0050.00 50.01 50.00 50.00 50.00 50.00 56.58 2.014 2.025 2.024 2.013 2.020 2.014 -4.195 4.104 4.292 4.222 4.465 4.467 4.288118.7 120.0 119.6 121.2 120.8 123.0 -46.1 46.6 46.4 47.0 46.9 47.7 -0.288 0.288 0.289 0.289 0.289 0.290 -

[0122] Table 1 cont.Example E57 E58 E59 E60 E61 E62 E63TiO245.00 43.69 45.00 43.75 42.66 45.00 43.69 SiO2 12.13 13.42 11.10 12.19 13.42 13.42 13.42BaO 10.14 10.14 10.14 10.14 10.14 10.14 10.14SP24-098 E57 E58 E59 E60 E61 E62 E6310.00 10.00 10.00 10.00 10.00 10.00 10.009.86 9.86 9.86 9.86 9.86 9.86 9.86- - - - - - -5.00 5.00 5.00 5.00 5.00 3.63 5.001.29 1.31 2.32 2.48 2.34 0.68 0.65- - - - - - -6.58 6.58 6.58 6.58 6.58 7.27 7.24100.00 100.00 100.00 100.00 100.00 100.00 100.0030.00 30.00 30.00 30.00 30.00 30.00 30.0057.87 56.58 58.90 57.81 56.58 56.58 56.58 -- - - - - -4.380 4.354 4.502 4.434 4.417 4.305 4.399- - - - - - -- - - - - - -- - - - - - -

[0123] Table 1 cont.Example E64 E65 E66 E67 E68 E69 E70TiO2 42.66 42.77 50.00 50.00 46.64 45.04 45.04 SiO2 13.42 13.42 20.00 20.38 20.00 20.02 20.02BaO 10.14 10.14 10.14 13.47 10.14 18.93 18.93SrO 10.00 10.00 10.00 16.15 10.00 5.00 5.00CaO 9.86 9.86 9.86 - 9.86 6.01 6.01Y2O3 - - - - - 5.00 -ZrO2 5.00 3.66 - - - - -La2O3 1.17 1.78 - - - - 2.58Ta2O5 - - - - 3.36 - 2.42Nb2O3, 7.75 8.37 - - - - -Sum 100.00 100.00 100.00 100.00 100.00 100.00 100.00RO 30.00 30.00 30.00 29.62 30.00 29.94 29.94SP24-098 Example E64 E65 E66 E67 E68 E69 E70Sum of TiO2, Nb2O3, Ta2O5, 56.58 56.58 50.00 50.00 50.00 50.04 50.04 Y2O3, ZrO2, and La2O3 Refractive Index - - 2.021 2.003 2.010 1.977 1.995Density (g / cm3) 4.465 4.404 3.958 4.155 4.326 4.286 4.606Young's Modulus (GPa) - - 119.0 - 119.7 110.4 110.2Shear Modulus (GPa) - - 46.3 - 46.5 42.7 42.7Poisson's Ratio - - - - - - -

[0124] Table 1 cont.SP24-098

[0125] Table 1 cont.E78 E79 E80 E81 E8245.00 42.65 38.43 37.80 35.0015.73 17.73 20.00 17.20 20.0010.14 10.14 10.14 10.14 10.1410.00 10.00 10.00 10.00 10.009.86 9.86 9.86 9.86 9.862.42 2.42 2.42 2.42 2.422.58 2.58 2.58 2.58 2.58- - - - -- - - - -4.27 4.62 6.57 10.00 10.00100.00 100.00 100.00 100.00 100.0030.00 30.00 30.00 30.00 30.0054.27 52.27 50.00 52.80 50.002.050 2.040 2.030 2.060 2.0404.231 4.207 4.344 4.313 4.274123.3 122.5 125.2 123.3 120.947.8 47.5 48.7 47.8 47.00.289 0.289 0.287 0.290 0.285

[0126] Table 2SP24-098 C1 C2 C3 C4 C5 C6 C7 C820.00 32.80 34.90 37.07 39.80 41.70 42.52 44.721.834 1.858 1.878 1.9 1.919 1.938 1.95 1.9513.697 3.718 3.78 3.792 3.826 3.870 4.209 4.218108.1 109.8 112.8 112.6 115.3 116.5 106.1 103.342.3 43.0 44.1 44.1 45.0 45.4 41.7 40.20.0.278 0.277 0.279 0.278 0.281 0.284 0.285 0.286

[0127] As indicated by the example glass compositions in Table 1, glass compositions and theresultant glass articles as described herein have increased refractive index and low density such that the glass compositions and the resultant glass articles are more efficient at bending light while reducing size and weight.

[0128] As seen in Tables 1 and 2, when the cumulative index‐driving content (sum of TiO2,Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3) is less than the specified limit of 47 mol.%, the refractive index fails to meet the criteria of greater than or equal to 1.97. As exemplified, the relatively high refractive indices are, at least partially, the result of the relatively high cumulative index-driving content. For example, E1-E52 and E63-E79 contained at least 47 mol.% of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 and had a refractive index greater than or equal to 1.97. In contrast, comparative examples C1-C8 included 20 mol.%, 32.8 mol.%, 34.9 mol.%, 37.07 mol.%, 39.8 mol.%, 41.7 mol.%, 42.52 mol.%, and 44.72 mol.%, respectively, of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 and none achieved a refractive index greater than or equal to 1.97.

[0129] It will be apparent to those skilled in the art that various modifications and variationsmay be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.

Claims

SP24-098 CLAIMS1. A glass composition comprising:greater than or equal to 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%.

2. The glass composition of claim 1, wherein the glass composition is free or substantially-free of P2O5.

3. The glass composition of claim 1 or 2, wherein the glass composition comprises greaterthan or equal to 36 mol.% and less than or equal to 60 mol.% TiO2.

4. The glass composition of any one of claims 1 to 3, wherein the sum of TiO2, Nb2O3, Ta2O5,Y2O3, ZrO2, and La2O3 is greater than or equal to 48 mol.%.

5. The glass composition of any one of claims 1 to 4, wherein the glass composition comprisesgreater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Nb2O3.

6. The glass composition of any one of claims 1 to 5, wherein the glass composition comprisesgreater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Ta2O5.

7. The glass composition of any one of claims 1 to 6, wherein the glass composition comprisesgreater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Y2O3.SP24-0988. The glass composition of any one of claims 1 to 7, wherein the glass composition comprisesgreater than or equal to 0.1 mol.% and less than or equal to 12 mol.% ZrO2.

9. The glass composition of any one of claims 1 to 8, wherein the glass composition comprisesgreater than or equal to 0.1 mol.% and less than or equal to 12 mol.% La2O3.

10. The glass composition of any one of claims 1 to 9, wherein RO is greater than 25 mol.% and less than or equal to 40 mol.%.

11. The glass composition of any one of claims 1 to 10, wherein the glass composition comprises greater than or equal to 6 mol.% and less than or equal to 25 mol.% BaO.

12. The glass composition of any one of claims 1 to 11, wherein the glass composition comprises greater than or equal to 2 mol.% and less than or equal to 23 mol.% SrO.

13. The glass composition of any one of claims 1 to 12, wherein the glass composition comprises greater than 0 mol.% and less than or equal to 15 mol.% CaO.

14. The glass composition of any one of claims 1 to 13, wherein the glass composition comprises greater than or equal to 10 mol.% and less than or equal to 23 mol.% SiO2.

15. The glass composition of any one of claims 1 to 14, wherein the glass composition comprises: greater than or equal to 37 mol.% and less than or equal to 52 mol.% TiO2; greater than or equal to 18 mol.% and less than or equal to 23 mol.% SiO2; greater than or equal to 8 mol.% and less than or equal to 25 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 20 mol.% SrO.

16. A glass article comprising the glass composition of claim 1, wherein the glass article comprises:SP24-098 a refractive index (nd) at 589.3 nm greater than or equal to 1.97, and a density less than 4.8 g / cm3.

17. A glass composition comprising: greater than or equal to 38 mol.% and less than or equal to 50 mol.% TiO2; greater than or equal to 19 mol.% and less than or equal to 22 mol.% SiO2; greater than or equal to 10 mol.% and less than or equal to 20 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 17 mol.% SrO, wherein: the glass composition is free or substantially-free of B2O3; a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 49 mol.%, RO is greater than or equal to 27 mol.% and less than or equal to 31 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and the sum of all oxide components is equal to 100 mol.%.

18. The glass composition of claim 17, wherein the glass composition is free or substantially- free of P2O5.

19. The glass composition of claim 17 or 18, wherein the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 50 mol.%.

20. The glass composition of any one of claims 17 to 19, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 10 mol.% Nb2O3.

21. The glass composition of any one of claims 17 to 20, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% Ta2O5.

22. The glass composition of any one of claims 17 to 21, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% Y2O3.

23. The glass composition of any one of claims 17 to 22, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% ZrO2.SP24-098 24. The glass composition of any one of claims 17 to 23, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 6 mol.% La2O3.

25. The glass composition of any one of claims 17 to 24, wherein RO is greater than 28 mol.% and less than or equal to 30 mol.%.

26. The glass composition of any one of claims 17 to 25, wherein the glass composition comprises greater than or equal to 46 mol.% and less than or equal to 50 mol.% TiO2.

27. The glass composition of any one of claims 17 to 26, wherein the glass composition comprises greater than or equal to 2 mol.% and less than or equal to 12 mol.% SrO.

28. The glass composition of any one of claims 17 to 27, wherein the glass composition comprises greater than 0 mol.% and less than or equal to 10 mol.% CaO.

29. A glass article comprising the glass composition of claim 17, wherein the glass article comprises: a refractive index (nd) at 589.3 nm greater than or equal to 1.97, and a density less than 4.8 g / cm3.

30. A glass composition comprising: greater than or equal to 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2; greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; and greater than or equal to 0 mol.% and less than 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3 is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; andSP24-098 a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%.

31. The glass composition of claim 30, wherein the glass composition is free or substantially- free of P2O5.

32. The glass composition of claim 30 or 31, wherein the glass composition comprises greater than or equal to 36 mol.% and less than or equal to 60 mol.% TiO2.

33. The glass composition of any one of claims 30 to 32, wherein the sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 48 mol.%.

34. The glass composition of any one of claims 30 to 33, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to35. The glass composition of any one of claims 30 to 34, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Ta2O5.

36. The glass composition of any one of claims 30 to 35, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% Y2O3.

37. The glass composition of any one of claims 30 to 36, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% ZrO2.

38. The glass composition of any one of claims 30 to 37, wherein the glass composition comprises greater than or equal to 0.1 mol.% and less than or equal to 12 mol.% La2O3.

39. The glass composition of any one of claims 30 to 38, wherein the glass composition comprises greater than or equal to 1 mol.% and less than or equal to 8 mol.% B2O3.SP24-098 40. The glass composition of any one of claims 30 to 39, wherein RO is greater than 25 mol.% and less than or equal to 40 mol.%.

41. The glass composition of any one of claims 30 to 40, wherein the glass composition comprises greater than or equal to 6 mol.% and less than or equal to 25 mol.% BaO.

42. The glass composition of any one of claims 30 to 41, wherein the glass composition comprises greater than or equal to 2 mol.% and less than or equal to 23 mol.% SrO.

43. The glass composition of any one of claims 30 to 42, wherein the glass composition comprises greater than 0 mol.% and less than or equal to 15 mol.% CaO.

44. The glass composition of any one of claims 30 to 43, wherein the glass composition comprises greater than or equal to 10 mol.% and less than or equal to 25 mol.% SiO2.

45. The glass composition of any one of claims 30 to 44 wherein the glass composition comprises: greater than or equal to 37 mol.% and less than or equal to 52 mol.% TiO2; greater than or equal to 18 mol.% and less than or equal to 23 mol.% SiO2; greater than or equal to 8 mol.% and less than or equal to 25 mol.% BaO; and greater than or equal to 2 mol.% and less than or equal to 20 mol.% SrO.

46. A glass article comprising the glass composition of claim 30, wherein the glass article comprises: a refractive index (nd) at 589.3 nm greater than or equal to 1.97, and a density less than 4.8 g / cm3.

47. A glass article comprising: a glass composition comprising: greater than or equal to 35 mol.% and less than or equal to 62 mol.% TiO2; greater than or equal to 6 mol.% and less than or equal to 30 mol.% SiO2;SP24-098 greater than or equal to 1 mol.% and less than or equal to 30 mol.% BaO; and greater than or equal to 1 mol.% and less than or equal to 25 mol.% SrO; and greater than or equal to 0 mol.% and less than or equal to 10 mol.% B2O3, wherein: a sum of TiO2, Nb2O3, Ta2O5, Y2O3, ZrO2, and La2O3is greater than or equal to 47 mol.%, RO is greater than or equal to 20 mol.% and less than or equal to 50 mol.%, wherein RO is the sum of BaO, SrO, and CaO; and a total sum of concentrations of oxide components in the glass composition is equal to 100 mol.%, wherein the glass article comprises: an ultra-high refractive index (nd) at 589.3 nm greater than or equal to 2.05, and a density less than 4.8 g / cm3.

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