Borosilicate and borosilicate glasses with high refractive index and high blue light transmittance

Abstract

Glass is provided that contains silicon dioxide (SiO2) and / or boron oxide (B2O3) as glass-forming agents and has a refractive index n greater than or equal to 1.80. d (Measured at 587.56 nm), less than or equal to 5.5 g / cm³ 3 The glass exhibits high density (measured at 25°C) and high transmittance (especially for blue light). Optionally, the glass can be characterized by high transmittance in the visible and near-ultraviolet (near-UV) ranges of the electromagnetic spectrum and / or good glass-forming ability.

Description

[0001] This application claims priority under 35 USC § 119(e) to U.S. Provisional Patent Application Serial No. 63 / 076,551, filed September 10, 2020, which is incorporated by reference herein in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates generally to silicoborate and borosilicate glasses having high refractive index, low density, and high blue light transmission. BACKGROUND

[0003] Glasses are used in various optical devices, examples of which include augmented reality devices, virtual reality devices, mixed reality devices, eyeglasses, and the like. Properties required for glasses of this type often include high refractive index and low density. Other required properties can include high transmission in the visible and near-ultraviolet (near-UV) ranges of the electromagnetic spectrum and / or low optical dispersion. It can be challenging to demand a glass that has a combination of these properties that are desired and that can be formed from a composition that has good glass forming ability. For example, generally, as the refractive index of a glass increases, the density tends to increase as well. Materials such as TiO2and Nb2O5are often added to increase the refractive index of a glass without increasing the density of the glass. However, these materials often absorb blue and UV light, which can undesirably decrease the light transmission of the glass in this spectral region. Generally, attempts to increase the refractive index of a glass while maintaining low density and without decreasing transmission in the blue and UV regions of the spectrum can result in a decrease in the glass forming ability of the material. For example, crystallization and / or liquid-liquid phase separation can occur during a cooling process of a glass melt at cooling rates that are generally acceptable in the industry. Typically, the glass forming ability appears to decrease with increasing amounts of certain materials (e.g., ZrO2, Y2O3, Sc2O3, BeO, etc.).

[0004] Low density high refractive index glasses generally fall into one of two types of chemical systems depending on the glass formers employed: (a) silicoborate or borosilicate glasses, in which SiO2and / or B2O3are used as the primary glass former, and (b) phosphate glasses, in which P2O5is used as the primary glass former. The use of glasses that rely on other oxides as the primary glass former (GeO2, TeO2, Bi2O3, and V2O5) can be challenging due to cost, glass forming ability, optical properties, and / or production requirements.

[0005] Phosphate glasses can be characterized as having high refractive index and low density, however, production of phosphate glasses can be challenging due to the risk of volatilization of P2O5 from the melt and / or incompatibility with platinum. In addition, phosphate glasses are typically highly colored and can require an additional bleaching step to provide a glass with the desired transmission properties. In addition to this, phosphate glasses that exhibit high refractive index also tend to have increased optical dispersion.

[0006] Generally, silicate and borosilicate glasses are easier to produce and can exhibit high transmission without a bleaching step. However, compared to phosphate glasses, silicate and borosilicate glasses generally exhibit increased density as the refractive index increases.

[0007] Based on these considerations, there is a need for silicate and borosilicate glasses with high refractive index, low density, and high blue light transmission. SUMMARY

[0008] According to embodiments of the disclosure, a glass comprises: B2O3 from 9.0 mol% to 33.0 mol%, La2O3 from 15.0 mol% to 50.0 mol%, SiO2 greater than 0.0 mol%, wherein the ratio of SiO2 (expressed in mol%) to the sum of SiO2 and B2O3 (expressed in mol%) (SiO2 / (SiO2+B2O3)) is from 0.05 to 0.95, and at least one oxide selected from the group consisting of: Nb2O5, TiO2, ZrO2, Y2O3, Li2O, Ta2O5, Al2O3, BaO, Bi2O3, CaO, Er2O3, Gd2O3, K2O, Na2O, Nd2O3, P2O5, PbO, TeO2, WO3, Y2O3, Yb2O3, and ZnO, with the additional requirement that: Nb2O5 is from 0.0 mol% to 12.0 mol%, TiO2 is from 0.0 mol% to 40.0 mol%, ZrO2 is from 0.0 mol% to 13.5 mol%, Y2O3 is from 0.0 mol% to 3.0 mol%, ZnO is from 0.0 mol% to 0.8 mol%, Li2O is from 0.0 mol% to 0.5 mol%, and Ta2O5 is from 0.0 mol% to 1.5 mol%. The glass also has a refractive index parameter P n and a density parameter P d :

[0009] P n –(1.000+0.19*P d )>0.000 (IX)

[0010] wherein the refractive index parameter P n is calculated according to equation (VI):

[0011]

[0012] and

[0013] wherein the density parameter P d calculated according to equation (VII) below:

[0014]

[0015] and

[0016] wherein the glass has a transmittance index T i , wherein the transmittance index T i calculated according to equation (III) below:

[0017]

[0018] wherein each oxide listed in equation (VI), equation (VII) and equation (III) refers to the amount of the oxide in the glass expressed as mol%.

[0019] According to another embodiment of the present disclosure, the glass comprises: SiO2is 3.0 mol% or more, B2O3is 1.0 mol% or more, wherein the sum of (SiO2+B2O3) is 48.0 mol% or less, the total content of divalent metal oxides (RO) is 8.5 mol% or more, and at least one oxide selected from the group consisting of: Nb2O5, TiO2, ZrO2, Y2O3, Li2O, Ta2O5, Al2O3, BaO, Bi2O3, CaO, Er2O3, Gd2O3, K2O, Na2O, Nd2O3, P2O5, PbO, TeO2, WO3, Y2O3, Yb2O3, and ZnO, with the proviso that: Gd2O3is 0.0 mol% to 27.0 mol%, CaO is 0.0 mol% to 32.0 mol%, Li2O is 0.0 mol% to 7.0 mol%, MgO is 0.0 mol% to 5.0 mol%, Y2O3is 0.0 mol% to 1.5 mol%, Ta2O5is 0.0 mol% to 0.5 mol%, BaO is 0.0 mol% to 14.0 mol%, CdO is 0.0 mol% to 10.0 mol%, Bi2O3is 0.0 mol% to 20.0 mol%, PbO is 0.0 mol% to 1.0 mol%, HfO2is 0.0 mol% to 1.0 mol%, TeO2is 0.0 mol% to 5.0 mol%, Nb2O5is 0.0 mol% to 25.0 mol%, TiO2is 0.0 mol% to 18.0 mol%, ZnO is 0.0 mol% to 2.0 mol%, fluorine is 0.0 at% to 1.0 at%, the sum of (SiO2+B2O3+Alk2O+MgO+CaO+SrO+BaO+ZnO) is 69.0 mol% or less, where Alk2O is the total content of alkali metal oxides, and (RE m O n +TiO2+Nb2O5+ZrO2+Bi2O3+WO3) is 25.0 mol% or more, where RE m O n is the total content of rare earth metal oxides. The glass also has a refractive index parameter P n and a transmittance index T i :

[0020] P n –(2.055–0.36*T i )>0.000 (XI) (a)

[0021] where the refractive index parameter P n is calculated according to the following equation (VI):

[0022]

[0023] and

[0024] wherein the transmittance index T i is calculated according to the following equation (III):

[0025]

[0026] and each oxide listed in equation (VI) and equation (III) refers to the amount of oxide in the glass expressed in mole %.

[0027] According to another embodiment, the glass comprises: TiO2from 1.0 mole % to 40.0 mole %, B2O3from 1.0 mole % to 29.0 mole %, SiO2from 0.0 mole % to 32.0 mole %, wherein the sum of (SiO2+B2O3) is 45.0 mole % or less, and at least one oxide selected from the group consisting of: Nb2O5, ZrO2, La2O3, Y2O3, Li2O, Al2O3, BaO, Bi2O3, CaO, Er2O3, Gd2O3, Na2O, Nd2O3, P2O5, PbO, WO3, Y2O3, Yb2O3, and ZnO, with the additional requirement that: La2O3from 0.0 mole % to 30.0 mole %, ZrO2from 0.0 mole % to 7.8 mole %, Nb2O5from 0.0 mole % to 7.0 mole %, CaO from 0.0 mole % to 15.0 mole %, BaO from 0.0 mole % to 15.0 mole %, Li2O from 0.0 mole % to 3.5 mole %, GeO2from 0.0 mole % to 10.0 mole %, Al2O3from 0.0 mole % to 10.0 mole %, fluorine from 0.0 atom % to 1.0 atom %, the sum of (Y2O3+ZnO) from 0.0 mole % to 2.0 mole %, the total content of divalent metal oxides (RO) from 0.0 mole % to 40.0 mole %, and the total content of monovalent metal oxides (R2O) from 0.0 mole % to 15.0 mole %. The glass further has a transmittance index T i and further has a refractive power parameter P ref and a transmittance index T i :

[0028] P ref – (0.262 - 0.115 * T i )> 0.000 (XII)

[0029] wherein the refractive power parameter P ref is calculated according to the following equation (VIII):

[0030]

[0031] and

[0032] wherein the transmittance index T i is calculated according to equation (III) below:

[0033]

[0034] and each oxide listed in equation (VIII) and equation (III) refers to the amount of the oxide in the glass, expressed as mol%.

[0035] These and other aspects, objects, and features of the present disclosure will be understood and appreciated by those of ordinary skill in the art upon study of the following specification, claims, and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0036] In the drawings:

[0037] Figure 1 shows a plot of the transmittance index Ti calculated according to equation (III) versus the minimum wavelength (λ 70 ) corresponding to at least 70% total transmittance for some comparative example samples for glass samples having a thickness of 10 mm;

[0038] Figure 2 shows a plot of the density d RT (measured at room temperature, in g / cm 3 ) versus the density parameter P d calculated according to equation (VII) for some comparative example glasses as well as for some exemplary glasses according to embodiments of the present disclosure;

[0039] Figure 3 shows a plot of the refractive index n d (measured at 587.56 nm) versus the refractive index parameter P n calculated according to equation (VI) for some comparative example glasses as well as for some exemplary glasses according to embodiments of the present disclosure;

[0040] Figure 4 shows a plot of the ratio of the refractive index to the density ("refractive power") (n d -1) / d RT versus the refractive power parameter P ref calculated according to equation (VIII) for some comparative example glasses as well as for some exemplary glasses according to embodiments of the present disclosure;

[0041] Figure 5 is a plot of exemplary cooling schedules according to the "15 minute test" and "2.5 minute test" conditions for some exemplary glasses according to embodiments of the present disclosure;

[0042] Figure 6 FIG. 3 shows a plot of total transmittance τ versus wavelength for some comparative example glasses and some example glasses according to embodiments of the present disclosure;

[0043] Figure 7 FIG. 4 shows a plot of density parameter P calculated according to equation (VII) for some comparative example glasses and some example glasses according to embodiments of the present disclosure; d versus refractive index parameter P calculated according to equation (VI); n

[0044] Figure 8 FIG. 5 shows a plot of density d (in g / cm3) measured at room temperature versus refractive index n measured at 587.56 nm for some comparative example glasses and some example glasses according to embodiments of the present disclosure; RT 3 d

[0045] Figure 9 FIG. 6 shows a plot of transmittance index T calculated according to equation (III) for some comparative example glasses and some example glasses according to embodiments of the present disclosure; i versus refractive index parameter P calculated according to equation (VI); n

[0046] Figure 10 FIG. 7 shows a plot of transmittance index T calculated according to equation (III) for some comparative example glasses and some example glasses according to embodiments of the present disclosure; i versus refractive index n measured at 587.56 nm; d

[0047] Figure 11 FIG. 8 shows a plot of transmittance index T calculated according to equation (III) for some comparative example glasses and some example glasses according to embodiments of the present disclosure; i versus refractive power parameter P calculated according to equation (VIII); and ref

[0048] Figure 12 FIG. 9 shows a plot of transmittance index T calculated according to equation (III) for some comparative example glasses and some example glasses according to embodiments of the present disclosure; i versus the ratio of refractive index to density ("refractive power") (n d -1) / d RT DETAILED DESCRIPTION

[0049] ​​​​​​​​In the following detailed description, for purposes of explanation and not limitation, exemplary embodiments illustrating specific details are set forth in order to provide a thorough understanding of various principles of the disclosure. However, it will be apparent to those skilled in the art that the disclosure can be practiced in other embodiments that depart from these specific details without detracting from the various principles of the disclosure. In other instances, detailed descriptions of well-known devices, methods and materials are omitted so as not to obscure the description of the various principles of the application. Finally, where applicable, like reference numerals denote like elements throughout the various figures and the description.

[0050] As used herein, the term "and / or", when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0051] Those skilled in the art and having the benefit of the present disclosure will make modifications not detailed herein. Thus, it is to be understood that the embodiments shown in the drawings and described above are merely illustrative of the present disclosure and are not intended to limit the scope of the present disclosure, which is defined by the appended claims as construed in accordance with the principles of patent law including the doctrine of equivalents.

[0052] As used herein, the term "about" means quantities, dimensions, formulations, parameters, and other variables and characteristics are not and need not be exact, but can be approximated and / or larger or smaller, reflecting tolerances, conversion factors, rounding off, measurement error and the like, as well as the other factors that are known to those of skill in the art. When the term "about" is used in reference to a value or to an endpoint of a range, understanding that the disclosure encompasses the specific value or endpoint referred to. Whether the term "about" is used in reference to a value or to an endpoint of a range, the disclosure encompasses both implementations: one with "about" and one without "about." It will also be understood that the endpoint of each range is significant, both when the endpoint is used in connection with another endpoint and when the endpoint is used without reference to another endpoint.

[0053] The term "formed from" can mean one or more of the following: comprises, consists essentially of, or consists of. For example, a component formed from a particular material can comprise the particular material, consist essentially of the particular material, or consist of the particular material.

[0054] Unless otherwise stated, all compositions are expressed as mole percentages (mol%) of the ingredients. Those skilled in the art will understand that various melt components (e.g., fluorine, alkali metals, boron, etc.) may undergo different levels of volatility during melting (e.g., as a function of vapor pressure, melting time, and / or melting temperature). Therefore, the term "about" in relation to such components is intended to include values ​​that, when measured in the final article, differ from the composition of the ingredients provided herein by within about 0.2 mol%. In view of the foregoing, substantial compositional equivalence between the final article and the ingredient composition is anticipated. In some embodiments, when indicated, the composition may be expressed as a percentage of the ingredients by weight (wt%) of the oxides.

[0055] When fluorine is added to or present in an oxide glass, the molecular representation of the resulting glass composition can be expressed in different ways. In this disclosure, the fluorine content (when present) as a single item is expressed as an atomic percentage (atomic %), which is determined by multiplying the fraction of fluorine in the sum of all atoms in the glass composition by a factor of 100.

[0056] In this disclosure, the following method is used to represent fluorine-containing compositions and concentration ranges. The concentration limits for all oxides presented (e.g., SiO2, B2O3, Na2O, etc.) are based on the following assumptions: the corresponding cations (e.g., silicon [SiO2], B2O3, Na2O, etc.) are based on the following assumptions: 4+ ], Boron [B 3+ ], sodium [Na + The oxygen atoms in the oxides are initially present as the corresponding oxides. When fluorine is present, for the purpose of calculating the component concentration of the composition, a portion of the oxygen atoms in the oxides is equivalently replaced with fluorine (i.e., one oxygen atom is replaced by two fluorine atoms). It is assumed that the fluorine is present in the form of silicon fluoride (SiF4); therefore, the sum of all oxides and SiF4 is assumed to be 100 mol% or 100 wt% in all compositions.

[0057] In this document, the terms “free from” and “substantially free from” are used interchangeably, referring to the absence of an amount of a particular component in the glass composition that has not been intentionally added to the glass composition and / or the absence of that particular component. It should be understood that the glass composition may contain trace amounts of a particular constituent component as a contaminant or in an indeterminate amount of less than 0.10 mol%.

[0058] As used herein, when describing a particular constituent component in a glass composition, the term "uncertain" refers to a constituent component that is not intentionally added to the glass composition and is present in an amount of less than 0.05 mol%. Uncertain components may be unintentionally added to the glass composition as impurities in another constituent component and / or through migration of uncertain components into the composition during the processing of the glass composition.

[0059] The term "glass former" is used herein to refer to a component that, when present in a glass composition by itself (i.e., without other components, except in an unspecified amount), is capable of forming a glass when the melt is cooled at a rate of no more than about 200 °C / min to about 300 °C / min.

[0060] As used herein, the term "modifier" refers to an oxide of a monovalent or divalent metal, i.e., M2O or MO, where "M" represents the metal. A modifier can be added to a glass composition to change the atomic structure of the melt and the resulting glass. In some embodiments, the modifier can change the coordination number of the cations present in the glass former (e.g., boron in B2O3), which can result in the formation of a more polymeric atomic network and, as a result, can provide better glass formation.

[0061] As used herein, the term "RO" refers to the total content of divalent metal oxides, the term "R2O" refers to the total content of monovalent metal oxides, and the term "Alk2O" refers to the total content of alkali metal oxides. The term R2O encompasses alkali metal oxides (Alk2O) as well as other monovalent metal oxides, such as: Ag2O, Tl2O, and Hg2O. As discussed below, in the present disclosure, rare earth metal oxides are expressed herein in their standard formula (RE2O3), where the rare earth metal oxides have an oxidation state of "+3", and thus the rare earth metal oxides are not included in the term RO.

[0062] As used herein, the term "rare earth metal" refers to the metals listed in the lanthanide series of the IUPAC periodic table, plus yttrium and scandium. As used herein, the term "rare earth metal oxide" is used to describe oxides of rare earth metals in different redox states, such as "+3" for lanthanum in La₂O₃, "+4" for cerium in CeO₂, and "+2" for europium in EuO, etc. Generally, the redox state of rare earth metals in oxide glasses can be altered, and specifically, the redox state may change during melting, depending on the batch composition and / or the redox conditions in the furnace where the glass is melted and / or heat-treated (e.g., annealed). Unless otherwise stated, rare earth metal oxides herein are expressed in their standard form, where the rare earth metal oxide has a redox state of "+3". Therefore, when a rare earth metal with a redox state other than "+3" is added to a glass composition batch, the glass composition is recalculated by adding or subtracting some oxygen to maintain the stoichiometry. For example, when CeO2 (cerium in the "+4" redox state) is used as a batch component, the resulting glass composition is recalculated as if 2 moles of CeO2 were equivalent to 1 mole of Ce2O3, and the resulting glass composition exhibits Ce2O3. As used herein, the term "RE" refers to... m O n "RE2O3" is used to refer to the total content of rare earth metal oxides in all redox states, and the term "RE2O3" is used to refer to the total content of rare earth metal oxides in the "+3" redox state.

[0063] The density values ​​of the glass recorded in this article are obtained using measurements with an error of 0.001 g / cm³. 3 The specific gravity of the helium flask was measured at room temperature, and the unit is g / cm³. 3 As used in this paper, density measurements at room temperature (defined as d) RT This refers to measurements taken at 20°C or 25°C, and includes measurements obtained at temperatures ranging from 20°C to 25°C. It should be understood that room temperature may vary between about 20°C and about 25°C; however, for the purposes of this disclosure, density changes within the temperature range of 20°C to 25°C are expected to be less than 0.001 g / cm³. 3 The error is negligible and therefore is not expected to affect the room temperature density measurements recorded in this paper.

[0064] Unless otherwise stated, as used herein, the term "low density" means a density less than or equal to 5.5 g / cm³. 3 The term "low density parameter" refers to the density parameter P. d The value is less than or equal to 5.5 g / cm³. 3 .

[0065] As used herein, the term "refractive power" refers to the relationship of refractive index to density according to the proportion (n d -1) / d RT , where the refractive index n d is measured at 5587.56 nm and the density is measured at 25°C in units of g / cm 3 .

[0066] As used herein, good glass forming ability refers to the resistance of the melt to devitrification as the material cools. Glass forming ability can be measured by determining the critical cooling rate of the melt. As used herein, the term "critical cooling rate" or "v cr " refers to the minimum cooling rate at which a melt of a given composition forms glass free of visually observable crystals under an optical microscope at 100X to 500X magnification. The critical cooling rate can be used to measure the glass forming ability of a composition, i.e., the ability of a melt of a given glass composition to form glass upon cooling. Generally, the lower the critical cooling rate, the better the glass forming ability.

[0067] The term "liquidus temperature" herein refers to the temperature above which a glass composition is completely liquid without crystallization of the glass-forming components. The liquidus temperature values reported herein were obtained by measuring samples using DSC or by isochronal holding of samples encased in platinum foil. For samples measured using DSC, powdered samples were heated to 1250°C at 10 K / min. The end of the endothermic event corresponding to the melting of crystals was taken as the liquidus temperature. For the second technique (isochronal holding), glass blocks (about 1 cm 3 ) were encased in platinum foil (to avoid volatilization) and placed in a furnace at a given temperature for 17 hours. The glass blocks were then observed with an optical microscope to check for crystals.

[0068] Unless otherwise indicated, the refractive index values reported herein were measured at room temperature (about 25°C). The refractive index values of the glass samples were measured using a Metricon Model 2010 prism coupler refractometer with an error of about ±0.0002. The refractive index of the glass samples was measured at two or more wavelengths of about 406 nm, 473 nm, 532 nm, 633 nm, 828 nm, and 1064 nm using the Metricon. The correlations measured characterized the dispersion, which was then fitted with Cauchy's law equation or the Sellmeier equation to enable calculation of the refractive index of the sample at a given wavelength of interest between the measured wavelengths. In this context, the term "refractive index n d " refers to the refractive index calculated at a wavelength of 587.56 nm as described above, which corresponds to the helium d-line wavelength. As used herein, the term "refractive index n C"refractive index n" refers to the refractive index calculated at a wavelength of 656.3 nm as described above. In this context, the term "refractive index n F "refractive index n" refers to the refractive index calculated at a wavelength of 486.1 nm as described above. In this context, the term "refractive index n g "refractive index n" refers to the refractive index calculated at a wavelength of 435.8 nm as described above.

[0069] The term "high refractive index" or "high refractive index" as used herein, unless otherwise specified, refers to a glass having a refractive index value measured at a wavelength of 587.56 nm of greater than or equal to at least 1.80. In the case shown, the term "high refractive index" or "high refractive index" refers to a glass having a refractive index value measured at a wavelength of 587.56 nm of greater than or equal to 1.80, greater than or equal to at least 1.85, greater than or equal to 1.90, greater than or equal to 1.95, or greater than or equal to 2.00. The term "high refractive index parameter" as used herein refers to a refractive index parameter P n .

[0070] The term "internal transmission" as used herein, unless otherwise specified, is used to mean the transmission through a glass sample corrected for Fresnel losses. The term "transmission" is used to express the transmission value without accounting for Fresnel losses. The transmission of a glass sample is measured (1 nm resolution, using an integrating sphere) by a Carry 5000 spectrometer at a wavelength of 250 nm to 2500 nm for a 2 mm thick sample. The internal transmission value for a 10 mm thick sample is calculated between 375 nm and 1175 nm using the measured refractive index and the measured raw transmission.

[0071] The term "blue light" as used herein refers to blue and ultraviolet light corresponding to a wavelength of about 330 nm to about 480 nm. The term "internal transmission of blue light" as used herein refers to the transmission measured at a given wavelength corrected for Fresnel losses for a glass sample having a thickness of 10 mm. The term "transmission of blue light" refers to the transmission of blue light without accounting for Fresnel losses. As used herein, for internal transmission (accounting for Fresnel losses) in the blue light region, a sample having a thickness of 10 mm is considered acceptable when measured at a wavelength of 460 nm to have an internal transmission equal to or greater than 90%; is considered good when the internal transmission is equal to or greater than 95%; and is considered excellent when the internal transmission is equal to or greater than 97%.

[0072] Embodiments of the present disclosure generally relate to silicoborate and borosilicate glasses having high refractive index and high blue light transmission. In some embodiments, the glasses can also be characterized as low density and / or good glass formability. In some embodiments, the glasses are characterized as having good transmission for light in the visible range of the optical spectrum.

[0073] According to embodiments of the present disclosure, the glasses described herein comprise silica (Si02) and / or boron oxide (B203) as glass formers. Increasing the amount of the glass-forming oxides (e.g., Si02and B203) results in a corresponding increase in viscosity values at a given temperature, which can protect the melt from crystallization during cooling and thus provide a glass having a lower critical cooling rate. In some embodiments, the glasses of the present disclosure can comprise both Si02and B203to provide a glass having a desired critical cooling rate, i.e., a desired degree of glass formability.

[0074] According to some embodiments, the glass composition can comprise silica (Si02) in an amount greater than or equal to 0.0 mol to less than or equal to 45.0 mol%, and all ranges and sub-ranges therebetween. In some embodiments, the glass composition can comprise Si02in an amount: greater than or equal to 0.0 mol%, greater than or equal to 0.3 mol%, greater than or equal to 1.0 mol%, greater than or equal to 2.0 mol%, greater than or equal to 3.0 mol%, greater than or equal to 5.0 mol%, greater than or equal to 9.6 mol%, greater than or equal to 10.0 mol%, greater than or equal to 15.0 mol%, greater than or equal to 20.0 mol%, greater than or equal to 25.0 mol%, greater than or equal to 30.0 mol%, greater than or equal to 31.0 mol%, or greater than or equal to 40.0 mol%. In some other embodiments, the glass composition can comprise Si02in an amount: less than or equal to 45.0 mol%, less than or equal to 40.0 mol%, less than or equal to 32.0 mol%, less than or equal to 31.0 mol%, less than or equal to 30.0 mol%, less than or equal to 25.0 mol%, less than or equal to 20.0 mol%, less than or equal to 15.0 mol%, less than or equal to 10.0 mol%, less than or equal to 5.0 mol%, less than or equal to 3.0 mol%, less than or equal to 2.0 mol%, or less than or equal to 1.0 mol%. In some further embodiments, the glass composition can comprise Si02in an amount: 0.0 mol% to 45.0 mol%, 0.0 mol% to 40.0 mol%, 0.0 mol% to 32.0 mol%, 0.0 mol% to 10.0 mol%, 0.3 mol% to 45.0 mol%, 0.3 mol% to 40.0 mol%, 0.3 mol% to 30.0 mol%, 0.3 mol% to 10.0 mol%, 1.0 mol% to 25.0 mol%, 1.0 mol% to 10.0 mol%, 2.0 mol% to 25.0 mol%, 3.0 mol% to 45.0 mol%, 40.0 mol% to 3.0 mol%, 3.0 mol% to 30.0 mol%, 3.0 mol% to 20.0 mol%, 3.0 mol% to 10.0 mol%, 10.0 mol% to 45.0 mol%, 10.0 mol% to 40.0 mol%, 10.0 mol% to 30.0 mol%, 10.0 mol% to 20.0 mol%, 15.0 mol% to 31.0 mol%, 15.0 mol% to 30.0 mol%, 17 mol% to 26 mol%, 4 mol% to 20 mol%, or 15 mol% to 30 mol%.

[0075] According to some embodiments, the glass composition can include boron oxide (B2O3) in an amount greater than or equal to 1.0 mol.% to less than or equal to 45.0 mol.%, and all ranges and sub-ranges therebetween. In some embodiments, the glass composition can include B2O3 in an amount: greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 9.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 15.0 mol.%, greater than or equal to 16.9 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 25.0 mol.%, greater than or equal to 30.0 mol.%, greater than or equal to 35.0 mol.%, greater than or equal to 37.0 mol.%, greater than or equal to 38.0 mol.%, or greater than or equal to 39.0 mol.%. In some other embodiments, the glass composition can include B2O3 in an amount: less than or equal to 45.0 mol.%, less than or equal to 40.0 mol.%, less than or equal to 39.0 mol.%, less than or equal to 38.0 mol.%, less than or equal to 37.0 mol.%, less than or equal to 35.0 mol.%, less than or equal to 30.0 mol.%, less than or equal to 29.0 mol.%, less than or equal to 25.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 15.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 5.0 mol.%, less than or equal to 4.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, or less than or equal to 1.0 mol.%.In some embodiments, the glass composition can comprise B203in an amount of: 0.0 mol% to 45.0 mol%, 0.0 mol% to 40.0 mol%, 0.0 mol% to 30.0 mol%, 1.0 mol% to 45.0 mol%, 1.0 mol% to 40.0 mol%, 1.0 mol% to 35.0 mol%, 1.0 mol% to 29.0 mol%, 1.0 mol% to 15.0 mol%, 2.0 mol% to 35.0 mol%, 3.0 mol% to 35.0 mol%, 3.0 mol% to 29.0 mol%, 3.0 mol% to 15.0 mol%, 4.0 mol% to 40.0 mol%, 4.0 mol% to 25.0 mol%, 5.0 mol% to 40.0 mol%, 5.0 mol% to 37.0 mol%, 5.0 mol% to 29.0 mol%, 5.0 mol% to 25.0 mol%, 9.0 mol% to 33.0 mol%, 10.0 mol% to 25.0 mol%, 1.0 mol% to 29.0 mol%, 10.0 mol% to 33.0 mol%, 15.0 mol% to 38.0 mol%, 15.0 mol% to 35.0 mol%, 15.0 mol% to 33.0 mol%, 15.0 mol% to 29.0 mol%, 15.0 mol% to 25.0 mol%, 20.0 mol% to 38.0 mol%, 20.0 mol% to 35.0 mol%, 20.0 mol% to 33.0 mol%, 7.0 mol% to 33.0 mol%, 6.0 mol% to 30.0 mol%, or 12.0 mol% to 27.0 mol%.

[0076] However, the combination of Si02and B203may result in a decrease in the refractive index, which can make it more challenging to provide a glass with the desired high refractive index. Accordingly, in some embodiments, the total amount of Si02and B203in the glass (Si02+ B203) can be limited. In some embodiments, the glass composition can comprise an amount of the sum of (Si02+ B203) that is greater than or equal to 0.0 mol.% to less than or equal to 50.0 mol.%, and all ranges and sub-ranges therebetween. In some embodiments, the glass composition can comprise an amount of (Si02+ B203) that is greater than or equal to 0.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 6.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 30.0 mol.%, greater than or equal to 40.0 mol.%, greater than or equal to 44.0 mol.%, greater than or equal to 46.0 mol.%, or greater than or equal to 48.0 mol.%. In some other embodiments, the glass composition can comprise an amount of (Si02+ B203) that is less than or equal to 50.0 mol.%, less than or equal to 48.0 mol.%, less than or equal to 46.0 mol.%, less than or equal to 44.0 mol.%, less than or equal to 40.0 mol.%, less than or equal to 30.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 6.0 mol.%, less than or equal to 4.0 mol.%, or less than or equal to 2.0 mol.%. In some further embodiments, the glass composition can comprise an amount of (Si02+ B203) that is 0.0 mol.% to 50.0 mol.%, 0.0 mol.% to 48.0 mol.%, 0.0 mol.% to 46.0 mol.%, 0.0 mol.% to 44.0 mol.%, 0.0 mol.% to 20.0 mol.%, 2.0 mol.% to 50.0 mol.%, 2.0 mol.% to 48.0 mol.%, 2.0 mol.% to 46.0 mol.%, 2.0 mol.% to 44.0 mol.%, 2.0 mol.% to 20.0 mol.%, 6.0 mol.% to 46.0 mol.%, 6.0 mol.% to 20.0 mol.%, 10.0 mol.% to 48.0 mol.%, 10.0 mol.% to 46.0 mol.%, 10.0 mol.% to 40.0 mol.%, 20.0 mol.% to 50.0 mol.%, 20.0 mol.% to 48.0 mol.%, 20.0 mol.% to 46.0 mol.%, 20.0 mol.% to 40.0 mol.%, 24.0 mol.% to 48.0 mol.%, 30.0 mol.% to 48.0 mol.%, 30.0 mol.% to 44.0 mol.%, 30.0 mol.% to 40.0 mol.%, 7.0 mol.% to 40.0 mol.%, 23.0 mol.% to 48.0 mol.%, 23.0 mol.% to 40.0 mol.%, or 8.0 mol.% to 30.0 mol.%.

[0077] In some embodiments, the glass composition can have a ratio of Si02 / (Si02+ B203) [in mole percent] that is: greater than or equal to 0.05 to less than or equal to 1.0, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can have a ratio of Si02 / (Si02+ B203) [in mole percent] that is: greater than or equal to 0.05, greater than or equal to 0.1, greater than or equal to 0.1, greater than or equal to 0.2, greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.5, greater than or equal to 0.8, greater than or equal to 0.85, or greater than or equal to 0.9. In some other embodiments, the glass composition can have a ratio of Si02 / (Si02+ B203) [in mole percent] that is: less than or equal to 1.0, less than or equal to 0.9, less than or equal to 0.95, less than or equal to 0.8, less than or equal to 0.85, less than or equal to 0.5, less than or equal to 0.3, less than or equal to 0.25, less than or equal to 0.2, or less than or equal to 0.1. In some further embodiments, the glass composition can have a ratio of Si02 / (Si02+ B203) [in mole percent] that is: 0.05 to 1.0, 0.05 to 0.95, 0.05 to 0.9, 0.05 to 0.8, 0.05 to 0.6, 0.05 to 0.5, 0.05 to 0.3, 0.1 to 1.0, 0.1 to 0.8, 0.2 to 0.9, 0.2 to 0.8, 0.2 to 0.8, 0.3 to 1.0, 0.3 to 0.9, 0.3 to 0.8, 0.5 to 1.0, 0.5 to 0.9, 0.5 to 0.9, 0.5 to 0.8, 0.5 to 0.8, 0.8 to 0.9, 0.4 to 0.7, 0.3 to 0.6, or 0.4 to 0.7.

[0078] According to embodiments of the present disclosure, the glass can include one or more index of refraction enhancers added to increase the index of refraction of the glass. Examples of index of refraction enhancers that can be used in the glasses of the present disclosure include titanium oxide (Ti02), niobium oxide (Nb205), zirconium oxide (Zr02), and other rare earth metal oxides.

[0079] Titanium oxide (Ti02) is generally expected to increase the index of refraction of the glass, in combination with achieving low density and / or acceptably low dispersion. In some examples, titanium oxide can produce a yellow or brown colored glass, which can be addressed by bleaching, such as by oxidation state melting and / or annealing and / or by adding one or more oxidizing agents to the glass batch, examples of which include Ce02, As205, and Mn203, among others. In some cases, too high of an amount of titanium oxide can result in difficult to melt species (e.g., rutile (Ti02), sphene (CaTiSi05), and titanium niobate (e.g., Ti2Nb 10 O 29) and the like, which can cause the liquidus temperature of the glass to increase and, thus, can decrease the glass-forming ability of the melt. In addition, at high concentrations, titanium oxide can cause liquid-liquid phase separation of the melt, which can result in a loss of transmission of the glass.

[0080] In some embodiments, the glass composition can comprise titanium oxide (Ti02) in an amount greater than or equal to 0.0 mol.% to less than or equal to 59.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Ti02in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 0.3 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 6.0 mol.%, greater than or equal to 7.0 mol.%, greater than or equal to 9.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 30.0 mol.%, greater than or equal to 40.0 mol.%, greater than or equal to 50.0 mol.%, greater than or equal to 53.0 mol.%, greater than or equal to 55.0 mol.%, or greater than or equal to 57.0 mol.%. In some other embodiments, the glass composition can comprise Ti02in an amount: less than or equal to 59.0 mol.%, less than or equal to 57.0 mol.%, less than or equal to 55.0 mol.%, less than or equal to 53.0 mol.%, less than or equal to 50.0 mol.%, less than or equal to 40.0 mol.%, less than or equal to 30.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 6.0 mol.%, less than or equal to 4.0 mol.%, or less than or equal to 2.0 mol.%. In some further embodiments, the glass composition can comprise Ti02in an amount: 0.0 mol.% to 59.0 mol.%, 0.0 mol.% to 50.0 mol.%, 0.0 mol.% to 40.0 mol.%, 0.0 mol.% to 18.0 mol.%, 0.3 mol.% to 40.0 mol.%, 0.3 mol.% to 18.0 mol.%, 1.0 mol.% to 40.0 mol.%, 1.0 mol.% to 18.0 mol.%, 2.0 mol.% to 53.0 mol.%, 2.0 mol.% to 30.0 mol.%, 4.0 mol.% to 30.0 mol.%, 6.0 mol.% to 59.0 mol.%, 6.0 mol.% to 53.0 mol.%, 10.0 mol.% to 55.0 mol.%, 10.0 mol.% to 50.0 mol.%, 10.0 mol.% to 30.0 mol.%, 20.0 mol.% to 55.0 mol.%, 20.0 mol.% to 50.0 mol.%, 20.0 mol.% to 30.0 mol.%, 30.0 mol.% to 55.0 mol.%, 30.0 mol.% to 50.0 mol.%, 40.0 mol.% to 59.0 mol.%, 40.0 mol.% to 57.0 mol.%, 40.0 mol.% to 50.0 mol.%, 7.0 mol.% to 24.0 mol.%, 21.0 mol.% to 38.0 mol.%, or 30.0 mol.% to 54.0 mol.%.

[0081] Similar to titanium oxide, niobium oxide (Nb2O5) can be used in some aspects of the disclosure to increase the refractive index of the glass while maintaining a low density. However, niobium oxide introduces a yellow color to the glass that cannot be bleached out in the same way as titanium oxide, which results in a loss of transmission, particularly in the blue and UV ranges. Similar to titanium oxide, niobium oxide can cause crystallization and / or phase separation of the melt. In some cases, niobium oxide can provide a glass with a high optical dispersion, which can be significantly higher than that induced when titanium oxide and some other refractive index enhancers are added at similar concentrations. The effect of niobium oxide can be influenced by other components of the glass, and thus it can be challenging to determine the exact limit of niobium oxide. In some embodiments, the glass can be free or substantially free of niobium oxide.

[0082] In some embodiments, the glass composition can comprise niobium oxide (Nb2Os) in an amount greater than or equal to 0.0 mol.% to less than or equal to 25.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Nb2Os in an amount greater than or equal to 0.0 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 15.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 22.0 mol.%, greater than or equal to 23.0 mol.%, or greater than or equal to 24.0 mol.%. In some other embodiments, the glass composition can comprise Nb2Os in an amount less than or equal to 25.0 mol.%, less than or equal to 24.0 mol.%, less than or equal to 23.0 mol.%, less than or equal to 22.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 15.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 5.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, or less than or equal to 1.0 mol.%. In some further embodiments, the glass composition can comprise Nb2Os in an amount from 0.0 mol.% to 25.0 mol.%, from 0.0 mol.% to 22.0 mol.%, from 0.0 mol.% to 12.0 mol.%, from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 7.0 mol.%, from 0.3 mol.% to 15.0 mol.%, from 0.3 mol.% to 12.0 mol.%, from 0.3 mol.% to 7.0 mol.%, from 1.0 mol.% to 10.0 mol.%, from 2.0 mol.% to 25.0 mol.%, from 2.0 mol.% to 22.0 mol.%, from 3.0 mol.% to 23.0 mol.%, from 3.0 mol.% to 20.0 mol.%, from 3.0 mol.% to 10.0 mol.%, from 5.0 mol.% to 23.0 mol.%, from 10.0 mol.% to 25.0 mol.%, from 10.0 mol.% to 23.0 mol.%, from 15.0 mol.% to 25.0 mol.%, from 15.0 mol.% to 22.0 mol.%, from 15.0 mol.% to 20.0 mol.%, from 11.0 mol.% to 22.0 mol.%, from 8.0 mol.% to 20.0 mol.%, or from 10.0 mol.% to 21.0 mol.%.

[0083] Zirconia (Zr02) is another example of an oxide that can increase the refractive index of the glasses of the disclosure while maintaining an acceptably low density. In some examples, Zr02may provide a glass with a higher density than the case of Ti02and Nb205, at a similar refractive index value. Zr02also increases the viscosity of the melt, which can help protect the melt from crystallization. Unlike other refractive index enhancers that can provide a low density to the glass (e.g., Ti02and Nb205), Zr02does not introduce color in the visible and near-UV range to the glass, which can help maintain high transmission of the glass. However, high concentrations of zirconia oxide can lead to crystallization of refractory minerals (e.g., zirconia (Zr02), zircon (ZrSi04), and calcium zirconate (CaZr03), among others), which can increase the liquidus temperature. As a result, crystallization can occur at a lower viscosity, which can decrease the glass forming ability of the melt (i.e., can increase the critical cooling rate). To address these challenges, according to one aspect of the disclosure, the zirconia oxide content in the glass is less than or equal to 13.5 mol%, and in some examples, the glass is free or substantially free of zirconia oxide. In some cases, for example when there are low requirements for glass forming ability, the glass can include a higher amount of zirconia oxide.

[0084] In some embodiments, the glass composition can comprise zirconia (Zr02) in an amount greater than or equal to 0.0 mol.% to less than or equal to 13.5 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Zr02in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 6.1 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 10.5 mol.%, greater than or equal to 11.5 mol.%, or greater than or equal to 12.5 mol.%. In some other embodiments, the glass composition can comprise Zr02in an amount: less than or equal to 13.5 mol.%, less than or equal to 12.5 mol.%, less than or equal to 11.5 mol.%, less than or equal to 10.5 mol.%, less than or equal to 10.0 mol.%, less than or equal to 5.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, or less than or equal to 1.0 mol.%. In some further embodiments, the glass composition can comprise Zr02in an amount: 0.0 mol.% to 13.5 mol.%, 0.0 mol.% to 10.5 mol.%, 0.0 mol.% to 7.8 mol.%, 0.3 mol.% to 13.5 mol.%, 0.3 mol.% to 10.0 mol.%, 0.3 mol.% to 7.8 mol.%, 1.0 mol.% to 11.5 mol.%, 1.0 mol.% to 10.0 mol.%, 2.0 mol.% to 11.5 mol.%, 2.0 mol.% to 10.0 mol.%, 3.0 mol.% to 13.5 mol.%, 5.0 mol.% to 13.5 mol.%, 10.0 mol.% to 12.5 mol.%, 6.5 mol.% to 12.4 mol.%, 3.6 mol.% to 13.2 mol.%, or 6.8 mol.% to 12.4 mol.%.

[0085] In some embodiments, rare earth metal oxides can be added to the glass composition to increase the refractive index of the glasses of the present disclosure. Examples of rare earth metal oxides that can be added to the glasses of the present disclosure include La2O3, Gd2O3, Yb2O3, Y2O3, and Sc2O3. In some embodiments, the glass composition comprises at least one rare earth metal oxide selected from the group consisting of La2O3, Gd2O3, Yb2O3, and combinations thereof. The oxides of the latter two elements (Y2O3 and Sc2O3) can also provide a relatively low density to the glass, lower than titanium oxide and niobium oxide at similar refractive indices. However, scandium oxide (Sc2O3) can be expensive and thus can not be desirable for mass production. In some cases, Sc2O3 can be acceptable when the cost of the glass batch materials has a lower priority. The cost of yttrium oxide (Y2O3) is lower than that of scandium oxide. However, in some cases, Y2O3 can decrease the glass formability of the glass (i.e., increase the critical cooling rate), even at lower concentrations. Thus, according to some embodiments of the present disclosure, the glass can be free or substantially free of Y2O3.

[0086] In some embodiments, the glass composition can comprise Y2O3 in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Y2O3 in an amount greater than or equal to 0.0 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 1.5 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 7.5 mol.%, greater than or equal to 8.5 mol.%, greater than or equal to 9.0 mol.%, or greater than or equal to 9.5 mol.%. In some other embodiments, the glass composition can comprise Y2O3 in an amount less than or equal to 10.0 mol.%, less than or equal to 9.5 mol.%, less than or equal to 9.0 mol.%, less than or equal to 8.5 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.5 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, or less than or equal to 0.5 mol.%. In some further embodiments, the glass composition can comprise Y2O3 in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 8.5 mol.%, from 0.0 mol.% to 3.0 mol.%, from 0.0 mol.% to 2.5 mol.%, from 0.0 mol.% to 1.5 mol.%, from 1.0 mol.% to 9.0 mol.%, from 1.5 mol.% to 10.0 mol.%, from 2.5 mol.% to 7.5 mol.%, from 5.0 mol.% to 8.5 mol.%, from 1.5 mol.% to 5.5 mol.%, from 4.7 mol.% to 7.3 mol.%, or from 7.3 mol.% to 9.9 mol.%.

[0087] In some aspects, lanthanum oxide (La2O3) can be a preferred refractive index enhancer among the rare earth metal oxides (in addition to Y2O3 and Sc2O3). La2O3 can provide lower density for the glasses of the present disclosure at similar refractive indices than several other rare earth metal oxides. La2O3 can also provide acceptable good glass forming for the glass compositions and is one of the most cost effective rare earth metal oxides. Thus, in some aspects of the present disclosure, the glass composition can comprise at least some amount of La2O3. However, in some cases, when the concentration of La2O3 becomes too high, lanthanum oxide can cause precipitation of refractory species, such as lanthanum silicate (La4Si3O 12La2SiO5, La2Si2O7), lanthanum borates (LaBO3, LaB3O6), lanthanum niobates (LaNbO4), lanthanum zirconates (La2ZrO5, La2Zr2O7), and lanthanum titanates (La2TiO5, La2Ti2O7), among others, which can increase the liquidus temperature of the glass and can decrease the glass-forming ability of the composition. In addition, high concentrations of La2O3may stimulate phase separation in the melt, which results in a loss of transmittance of the resulting glass. Similar negative effects can also occur with the addition of other rare earth metal oxides in high concentrations.

[0088] In some embodiments, the glass composition can comprise lanthanum oxide (La2O3) in an amount greater than or equal to 0.0 mol.% to less than or equal to 50.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise La2O3 in an amount greater than or equal to 0.0 mol.%, greater than or equal to 0.3 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 6.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 15.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 30.0 mol.%, greater than or equal to 40.0 mol.%, greater than or equal to 44.0 mol.%, greater than or equal to 46.0 mol.%, or greater than or equal to 48.0 mol.%. In some other embodiments, the glass composition can comprise La2O3 in an amount less than or equal to 50.0 mol.%, less than or equal to 48.0 mol.%, less than or equal to 46.0 mol.%, less than or equal to 44.0 mol.%, less than or equal to 40.0 mol.%, less than or equal to 30.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 6.0 mol.%, less than or equal to 4.0 mol.%, or less than or equal to 2.0 mol.%. In some further embodiments, the glass composition can comprise La2O3 in an amount from 0.0 mol.% to 50.0 mol.%, from 0.0 mol.% to 44.0 mol.%, from 0.0 mol.% to 30.0 mol.%, from 0.0 mol.% to 20.0 mol.%, from 0.3 mol.% to 30.0 mol.%, from 0.3 mol.% to 20.0 mol.%, from 2.0 mol.% to 20.0 mol.%, from 4.0 mol.% to 44.0 mol.%, from 6.0 mol.% to 50.0 mol.%, from 6.0 mol.% to 46.0 mol.%, from 6.0 mol.% to 40.0 mol.%, from 6.0 mol.% to 20.0 mol.%, from 10.0 mol.% to 46.0 mol.%, from 10.0 mol.% to 40.0 mol.%, from 10.0 mol.% to 20.0 mol.%, from 15.0 mol.% to 50.0 mol.%, from 15.0 mol.% to 40.0 mol.%, from 15.0 mol.% to 30.0 mol.%, from 20.0 mol.% to 40.0 mol.%, from 30.0 mol.% to 48.0 mol.%, from 30.0 mol.% to 46.0 mol.%, from 30.0 mol.% to 44.0 mol.%, from 30.0 mol.% to 40.0 mol.%, from 7.0 mol.% to 25.0 mol.%, from 25.0 mol.% to 42.0 mol.%, or from 25.0 mol.% to 46.0 mol.%.

[0089] In some embodiments, the glasses of the present disclosure can optionally include additional and / or alternative refractive index enhancers (e.g., tungsten oxide (WO3), tantalum oxide (Ta2O5), thorium oxide (ThO2), bismuth oxide (Bi2O3)), which, if present, can be used in small amounts. In some embodiments, the glasses of the present disclosure are free or substantially free of tungsten oxide (WO3), tantalum oxide (Ta2O5), thorium oxide (ThO2), bismuth oxide (Bi2O3). In some embodiments, the glasses can optionally include additional and / or alternative refractive index enhancers selected from the group consisting of vanadium pentoxide (V2O5), molybdenum oxide (MoO3), germanium oxide (GeO2), tellurium oxide (TeO2), fluorides (e.g., ZrF4, LaF3, etc.), and thallium oxide (Tl2O). In some cases, refractive index enhancers such as V2O5, MoO3, GeO2, TeO2, fluorides, and Tl2O can not be as preferred generally due to low transmission, cost, and / or environmental considerations; however, in some cases, these refractive index enhancers can be used.

[0090] In some embodiments, the glass composition can comprise tantalum oxide (Ta2Os) in an amount greater than or equal to 0.0 mol.% to less than or equal to 5.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Ta2Os in an amount greater than or equal to 0.0 mol.%, greater than or equal to 0.2 mol.%, greater than or equal to 0.4 mol.%, greater than or equal to 0.6 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 4.4 mol.%, greater than or equal to 4.6 mol.%, or greater than or equal to 4.8 mol.%. In some other embodiments, the glass composition can comprise Ta2Os in an amount less than or equal to 5.0 mol.%, less than or equal to 4.8 mol.%, less than or equal to 4.6 mol.%, less than or equal to 4.4 mol.%, less than or equal to 4.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, less than or equal to 0.6 mol.%, less than or equal to 0.5 mol.%, less than or equal to 0.4 mol.%, or less than or equal to 0.2 mol.%. In some further embodiments, the glass composition can comprise Ta2Os in an amount from 0.0 mol.% to 5.0 mol.%, from 0.0 mol.% to 4.4 mol.%, from 0.0 mol.% to 2.0 mol.%, from 0.0 mol.% to 1.5 mol.%, from 0.0 mol.% to 0.5 mol.%, from 0.2 mol.% to 4.4 mol.%, from 0.2 mol.% to 2.0 mol.%, from 0.4 mol.% to 4.4 mol.%, from 0.6 mol.% to 4.6 mol.%, from 0.6 mol.% to 4.0 mol.%, from 0.6 mol.% to 2.0 mol.%, from 1.0 mol.% to 5.0 mol.%, from 1.0 mol.% to 4.6 mol.%, from 1.0 mol.% to 4.0 mol.%, from 2.0 mol.% to 4.0 mol.%, from 3.0 mol.% to 5.0 mol.%, from 3.0 mol.% to 4.6 mol.%, from 3.0 mol.% to 4.4 mol.%, from 3.0 mol.% to 4.0 mol.%, from 1.0 mol.% to 3.0 mol.%, from 2.0 mol.% to 4.0 mol.%, or from 1.0 mol.% to 4.0 mol.%.

[0091] In some embodiments, the glass composition can comprise bismuth oxide (Bi2O3) in an amount greater than or equal to 0.0 mol.% to less than or equal to 20.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Bi2O3 in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 15.0 mol.%, greater than or equal to 17.0 mol.%, greater than or equal to 18.0 mol.%, or greater than or equal to 19.0 mol.%. In some other embodiments, the glass composition can comprise Bi2O3 in an amount: less than or equal to 20.0 mol.%, less than or equal to 19.0 mol.%, less than or equal to 18.0 mol.%, less than or equal to 17.0 mol.%, less than or equal to 15.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 5.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, or less than or equal to 1.0 mol.%. In some further embodiments, the glass composition can comprise Bi2O3 in an amount: 0.0 mol.% to 20.0 mol.%, 0.0 mol.% to 10.0 mol.%, 1.0 mol.% to 5.0 mol.%, 2.0 mol.% to 15.0 mol.%, 3.0 mol.% to 20.0 mol.%, 3.0 mol.% to 18.0 mol.%, 5.0 mol.% to 18.0 mol.%, 5.0 mol.% to 15.0 mol.%, 10.0 mol.% to 20.0 mol.%, 10.0 mol.% to 18.0 mol.%, 10.0 mol.% to 17.0 mol.%, 5.0 mol.% to 10.0 mol.%, 6.0 mol.% to 14.0 mol.%, or 3.0 mol.% to 10.0 mol.%.

[0092] In some embodiments, the glass composition can comprise tungsten oxide (WO3) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise WO3 in an amount greater than or equal to 0.0 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, or greater than or equal to 7.5 mol.%. In some other embodiments, the glass composition can comprise WO3 in an amount less than or equal to 10.0 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, or less than or equal to 2.5 mol.%. In some further embodiments, the glass composition can comprise WO3 in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 7.5 mol.%, from 0.0 mol.% to 5.0 mol.%, from 0.0 mol.% to 2.5 mol.%, from 2.5 mol.% to 10.0 mol.%, from 2.5 mol.% to 7.5 mol.%, from 2.5 mol.% to 5.0 mol.%, from 5.0 mol.% to 10.0 mol.%, from 5.0 mol.% to 7.5 mol.%, from 4.5 mol.% to 7.9 mol.%, from 5.9 mol.% to 9.6 mol.%, or from 3.0 mol.% to 8.0 mol.%.

[0093] In some embodiments, the glass composition can comprise germanium oxide (Ge02) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Ge02in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 1.5 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 7.5 mol.%, greater than or equal to 8.5 mol.%, greater than or equal to 9.0 mol.%, or greater than or equal to 9.5 mol.%. In some other embodiments, the glass composition can comprise Ge02in an amount: less than or equal to 10.0 mol.%, less than or equal to 9.5 mol.%, less than or equal to 9.0 mol.%, less than or equal to 8.5 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, less than or equal to 2.5 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, or less than or equal to 0.5 mol.%. In some further embodiments, the glass composition can comprise Ge02in an amount: 0.0 mol.% to 10.0 mol.%, 0.0 mol.% to 2.5 mol.%, 0.5 mol.% to 2.5 mol.%, 1.0 mol.% to 10.0 mol.%, 1.0 mol.% to 9.0 mol.%, 1.0 mol.% to 7.5 mol.%, 1.5 mol.% to 9.0 mol.%, 1.5 mol.% to 7.5 mol.%, 2.5 mol.% to 10.0 mol.%, 2.5 mol.% to 9.0 mol.%, 2.5 mol.% to 7.5 mol.%, 5.0 mol.% to 8.5 mol.%, 5.0 mol.% to 7.5 mol.%, 7.5 mol.% to 9.5 mol.%, 7.0 mol.% to 9.9 mol.%, 3.4 mol.% to 8.3 mol.%, or 5.0 mol.% to 9.0 mol.%.

[0094] In some embodiments, the glass composition can comprise tellurium oxide (Te02) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Te02in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 1.5 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 7.5 mol.%, greater than or equal to 8.5 mol.%, greater than or equal to 9.0 mol.%, or greater than or equal to 9.5 mol.%. In some other embodiments, the glass composition can comprise Te02in an amount: less than or equal to 10.0 mol.%, less than or equal to 9.5 mol.%, less than or equal to 9.0 mol.%, less than or equal to 8.5 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, less than or equal to 2.5 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, or less than or equal to 0.5 mol.%. In some further embodiments, the glass composition can comprise Te02in an amount: 0.0 mol.% to 10.0 mol.%, 0.0 mol.% to 5.0 mol.%, 0.0 mol.% to 2.5 mol.%, 0.5 mol.% to 10.0 mol.%, 0.5 mol.% to 2.5 mol.%, 1.0 mol.% to 9.0 mol.%, 1.0 mol.% to 7.5 mol.%, 1.5 mol.% to 9.0 mol.%, 1.5 mol.% to 7.5 mol.%, 2.5 mol.% to 9.0 mol.%, 2.5 mol.% to 7.5 mol.%, 5.0 mol.% to 9.5 mol.%, 5.0 mol.% to 8.5 mol.%, 5.0 mol.% to 7.5 mol.%, 1.9 mol.% to 6.0 mol.%, 5.0 mol.% to 9.2 mol.%, or 3.5 mol.% to 9.2 mol.%.

[0095] In some embodiments, the glass composition can comprise hafnium oxide (Hf02) in an amount greater than or equal to 0.0 mol.% to less than or equal to 5.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Hf02in an amount greater than or equal to 0.0 mol.%, greater than or equal to 0.2 mol.%, greater than or equal to 0.4 mol.%, greater than or equal to 0.6 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 4.4 mol.%, greater than or equal to 4.6 mol.%, or greater than or equal to 4.8 mol.%. In some other embodiments, the glass composition can comprise Hf02in an amount less than or equal to 5.0 mol.%, less than or equal to 4.8 mol.%, less than or equal to 4.6 mol.%, less than or equal to 4.4 mol.%, less than or equal to 4.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, less than or equal to 1.0 mol.%, less than or equal to 0.6 mol.%, less than or equal to 0.4 mol.%, or less than or equal to 0.2 mol.%. In some further embodiments, the glass composition can comprise Hf02in an amount from 0.0 mol.% to 5.0 mol.%, from 0.0 mol.% to 4.4 mol.%, from 0.0 mol.% to 2.0 mol.%, from 0.0 mol.% to 1.0 mol.%, from 0.2 mol.% to 5.0 mol.%, from 0.2 mol.% to 4.4 mol.%, from 0.2 mol.% to 2.0 mol.%, from 0.2 mol.% to 1.0 mol.%, from 0.4 mol.% to 2.0 mol.%, from 0.6 mol.% to 4.0 mol.%, from 0.6 mol.% to 2.0 mol.%, from 1.0 mol.% to 4.6 mol.%, from 1.0 mol.% to 4.0 mol.%, from 2.0 mol.% to 4.6 mol.%, from 2.0 mol.% to 4.0 mol.%, from 3.0 mol.% to 4.8 mol.%, from 3.0 mol.% to 4.6 mol.%, from 3.0 mol.% to 4.4 mol.%, from 3.0 mol.% to 4.0 mol.%, from 1.0 mol.% to 3.0 mol.%, from 3.0 mol.% to 5.0 mol.%, or from 2.0 mol.% to 3.0 mol.%.

[0096] In some embodiments, the glass composition can comprise gadolinium oxide (Gd2O3) in an amount greater than or equal to 0.0 mol.% to less than or equal to 27.0 mol.%, and all ranges and sub-ranges between the values described above. In some embodiments, the glass composition can comprise Gd2O3 in an amount greater than or equal to 0.0 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 15.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 25.0 mol.%, or greater than or equal to 26.0 mol.%. In some other embodiments, the glass composition can comprise Gd2O3 in an amount less than or equal to 27.0 mol.%, less than or equal to 26.0 mol.%, less than or equal to 25.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 15.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 5.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, or less than or equal to 1.0 mol.%. In some further embodiments, the glass composition can comprise Gd2O3 in an amount from 0.0 mol.% to 27.0 mol.%, from 0.0 mol.% to 15.0 mol.%, from 2.0 mol.% to 27.0 mol.%, from 2.0 mol.% to 25.0 mol.%, from 2.0 mol.% to 15.0 mol.%, from 3.0 mol.% to 25.0 mol.%, from 5.0 mol.% to 25.0 mol.%, from 5.0 mol.% to 15.0 mol.%, from 10.0 mol.% to 27.0 mol.%, from 10.0 mol.% to 25.0 mol.%, from 10.0 mol.% to 20.0 mol.%, from 10.0 mol.% to 15.0 mol.%, from 15.0 mol.% to 26.0 mol.%, from 15.0 mol.% to 25.0 mol.%, from 15.0 mol.% to 20.0 mol.%, from 13.0 mol.% to 25.0 mol.%, from 4.0 mol.% to 24.0 mol.%, or from 10.0 mol.% to 26.0 mol.%.

[0097] In some embodiments, the glass composition can comprise alumina (AI2O3) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise AI2O3 in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 1.5 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 7.5 mol.%, greater than or equal to 8.5 mol.%, greater than or equal to 9.0 mol.%, or greater than or equal to 9.5 mol.%. In some other embodiments, the glass composition can comprise AI2O3 in an amount: less than or equal to 10.0 mol.%, less than or equal to 9.5 mol.%, less than or equal to 9.0 mol.%, less than or equal to 8.5 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, less than or equal to 2.5 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, or less than or equal to 0.5 mol.%. In some further embodiments, the glass composition can comprise AI2O3 in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 2.5 mol.%, from 0.5 mol.% to 8.5 mol.%, from 0.5 mol.% to 2.5 mol.%, from 1.0 mol.% to 9.0 mol.%, from 1.5 mol.% to 7.5 mol.%, from 2.5 mol.% to 9.0 mol.%, from 2.5 mol.% to 7.5 mol.%, from 5.0 mol.% to 10.0 mol.%, from 5.0 mol.% to 9.5 mol.%, from 5.0 mol.% to 8.5 mol.%, from 5.0 mol.% to 7.5 mol.%, from 4.2 mol.% to 9.3 mol.%, from 4.4 mol.% to 9.3 mol.%, or from 3.2 mol.% to 8.0 mol.%.

[0098] In some embodiments, the glasses of the present disclosure can be free or substantially free of fluorine. In some embodiments, the glass composition can comprise fluorine (F) in an amount greater than or equal to 0.0 atomic % to less than or equal to 1.0 atomic %, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise F in an amount: greater than or equal to 0.0 atomic %, greater than or equal to 0.05 atomic %, greater than or equal to 0.10 atomic %, greater than or equal to 0.15 atomic %, greater than or equal to 0.25 atomic %, greater than or equal to 0.5 atomic %, greater than or equal to 0.75 atomic %, greater than or equal to 0.85 atomic %, greater than or equal to 0.9 atomic %, or greater than or equal to 0.95 atomic %. In some other embodiments, the glass composition can comprise F in an amount: less than or equal to 1.0 atomic %, less than or equal to 0.95 atomic %, less than or equal to 0.9 atomic %, less than or equal to 0.85 atomic %, less than or equal to 0.75 atomic %, less than or equal to 0.5 atomic %, less than or equal to 0.25 atomic %, less than or equal to 0.15 atomic %, less than or equal to 0.10 atomic %, or less than or equal to 0.05 atomic %. In some further embodiments, the glass composition can comprise F in an amount: 0.0 atomic % to 1.0 atomic %, 0.0 atomic % to 0.85 atomic %, 0.0 atomic % to 0.25 atomic %, 0.05 atomic % to 0.85 atomic %, 0.05 atomic % to 0.25 atomic %, 0.15 atomic % to 1.0 atomic %, 0.15 atomic % to 0.9 atomic %, 0.15 atomic % to 0.75 atomic %, 0.5 atomic % to 0.9 atomic %, 0.5 atomic % to 0.85 atomic %, 0.5 atomic % to 0.75 atomic %, 0.75 atomic % to 0.95 atomic %, 0.24 atomic % to 0.68 atomic %, 0.36 atomic % to 0.83 atomic %, or 0.25 atomic % to 0.70 atomic %.

[0099] According to embodiments of the disclosure, the glass can include one or more modifiers. As described above, the term "modifier" refers to an oxide of a monovalent or divalent metal, i.e., M2O or MO, where "M" represents the metal. Modifiers can be added to the glass compositions of the disclosure to promote improved glass forming ability of the melt, i.e., to reduce the critical cooling rate. Examples of modifiers that can be used in the glasses of the disclosure include alkali and alkaline earth modifiers (e.g., CaO, MgO, BaO, Li2O, Na2O, and K2O), as well as other modifiers (e.g., ZnO and Ag2O). According to one embodiment, the glass compositions can include CaO and / or Li2O, which are found to provide the desired ratio of the index of refraction to the density of the glass. In some embodiments, other alkali and alkaline earth metal oxides (e.g., Na2O, K2O, MgO, SrO, BaO, etc.) as well as other modifiers that do not provide any color (e.g., ZnO, Ag2O, etc.) can be included in the glass compositions. While these other modifiers can not contribute as much as CaO and Li2O to providing the desired index of refraction and / or density, these modifiers can be added to the glass compositions to provide other properties. For example, barium oxide (BaO), potassium oxide (K2O), sodium oxide (Na2O), etc. can be added to increase the solubility of index raising agents (e.g., TiO2, Nb2O5, ZrO2, etc.) in the glass melt, which can result in an overall increase in the index of refraction of the glass and / or an increase in the ratio of the index of refraction to the density. According to one embodiment of the disclosure, the glass can include at least CaO as a modifier, as CaO is found to provide a good balance between the desired properties of density, index of refraction, and glass forming ability. Thus, in many examples of the disclosure, all or at least a portion of the modifiers present in the glass compositions are in the form of CaO. In some embodiments, the glass can be free or substantially free of modifiers.

[0100] In some embodiments, the glass composition can comprise calcium oxide (CaO) in an amount greater than or equal to 0.0 mol.% to less than or equal to 40.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise CaO in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 15.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 25.0 mol.%, greater than or equal to 30.0 mol.%, greater than or equal to 35.0 mol.%, greater than or equal to 37.0 mol.%, greater than or equal to 38.0 mol.%, or greater than or equal to 39.0 mol.%. In some other embodiments, the glass composition can comprise CaO in an amount: less than or equal to 40.0 mol.%, less than or equal to 39.0 mol.%, less than or equal to 38.0 mol.%, less than or equal to 37.0 mol.%, less than or equal to 35.0 mol.%, less than or equal to 30.0 mol.%, less than or equal to 25.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 15.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 5.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, or less than or equal to 1.0 mol.%. In some further embodiments, the glass composition can comprise CaO in an amount: 0.0 mol.% to 40.0 mol.%, 0.0 mol.% to 35.0 mol.%, 0.0 mol.% to 32.0 mol.%, 0.0 mol.% to 30.0 mol.%, 0.0 mol.% to 15.0 mol.%, 1.0 mol.% to 35.0 mol.%, 1.0 mol.% to 32.0 mol.%, 1.0 mol.% to 32.0 mol.%, 1.0 mol.% to 15.0 mol.%, 2.0 mol.% to 40.0 mol.%, 2.0 mol.% to 35.0 mol.%, 3.0 mol.% to 37.0 mol.%, 3.0 mol.% to 25.0 mol.%, 3.0 mol.% to 10.0 mol.%, 5.0 mol.% to 37.0 mol.%, 5.0 mol.% to 32.0 mol.%, 5.0 mol.% to 32.0 mol.%, 10.0 mol.% to 40.0 mol.%, 10.0 mol.% to 32.0 mol.%, 10.0 mol.% to 32.0 mol.%, 10.0 mol.% to 25.0 mol.%, 15.0 mol.% to 35.0 mol.%, 15.0 mol.% to 25.0 mol.%, 20.0 mol.% to 35.0 mol.%, 25.0 mol.% to 38.0 mol.%, 25.0 mol.% to 35.0 mol.%, 6 mol.% to 20 mol.%, 24 mol.% to 35 mol.%, or 11 mol.% to 25 mol.%.

[0101] In some embodiments, the glass composition can comprise zinc oxide (ZnO) in an amount greater than or equal to 0.0 mol.% to less than or equal to 5.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise ZnO in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 0.2 mol.%, greater than or equal to 0.4 mol.%, greater than or equal to 0.6 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 4.4 mol.%, greater than or equal to 4.6 mol.%, or greater than or equal to 4.8 mol.%. In some other embodiments, the glass composition can comprise ZnO in an amount: less than or equal to 5.0 mol.%, less than or equal to 4.8 mol.%, less than or equal to 4.6 mol.%, less than or equal to 4.4 mol.%, less than or equal to 4.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, less than or equal to 1.0 mol.%, less than or equal to 0.8 mol.%, less than or equal to 0.6 mol.%, less than or equal to 0.4 mol.%, or less than or equal to 0.2 mol.%. In some further embodiments, the glass composition can comprise ZnO in an amount: 0.0 mol.% to 5.0 mol.%, 0.0 mol.% to 4.4 mol.%, 0.0 mol.% to 2.0 mol.%, 0.0 mol.% to 0.8 mol.%, 0.2 mol.% to 2.0 mol.%, 0.4 mol.% to 5.0 mol.%, 0.4 mol.% to 4.4 mol.%, 0.6 mol.% to 2.0 mol.%, 1.0 mol.% to 4.6 mol.%, 1.0 mol.% to 4.0 mol.%, 2.0 mol.% to 4.0 mol.%, 3.0 mol.% to 4.8 mol.%, 3.0 mol.% to 4.4 mol.%, 1.0 mol.% to 5.0 mol.%, 2.0 mol.% to 4.0 mol.%, or 3.0 mol.% to 4.0 mol.%.

[0102] In some embodiments, the glass composition can comprise cadmium oxide (CdO) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise CdO in an amount greater than or equal to 0.0 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 1.5 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 7.5 mol.%, greater than or equal to 8.5 mol.%, greater than or equal to 9.0 mol.%, or greater than or equal to 9.5 mol.%. In some other embodiments, the glass composition can comprise CdO in an amount less than or equal to 10.0 mol.%, less than or equal to 9.5 mol.%, less than or equal to 9.0 mol.%, less than or equal to 8.5 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, less than or equal to 2.5 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, or less than or equal to 0.5 mol.%. In some further embodiments, the glass composition can comprise CdO in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 8.5 mol.%, from 0.0 mol.% to 2.5 mol.%, from 0.5 mol.% to 8.5 mol.%, from 0.5 mol.% to 2.5 mol.%, from 1.0 mol.% to 10.0 mol.%, from 1.0 mol.% to 9.0 mol.%, from 1.0 mol.% to 7.5 mol.%, from 1.5 mol.% to 10.0 mol.%, from 1.5 mol.% to 7.5 mol.%, from 2.5 mol.% to 9.0 mol.%, from 2.5 mol.% to 7.5 mol.%, from 5.0 mol.% to 9.0 mol.%, from 5.0 mol.% to 7.5 mol.%, from 2.0 mol.% to 6.5 mol.%, from 2.1 mol.% to 9.3 mol.%, or from 4.5 mol.% to 8.5 mol.%.

[0103] In some embodiments, the glass composition can comprise PbO in an amount greater than or equal to 0.0 mol.% to less than or equal to 5.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise PbO in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 0.2 mol.%, greater than or equal to 0.4 mol.%, greater than or equal to 0.6 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 4.4 mol.%, greater than or equal to 4.6 mol.%, or greater than or equal to 4.8 mol.%. In some other embodiments, the glass composition can comprise PbO in an amount: less than or equal to 5.0 mol.%, less than or equal to 4.8 mol.%, less than or equal to 4.6 mol.%, less than or equal to 4.4 mol.%, less than or equal to 4.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, less than or equal to 1.0 mol.%, less than or equal to 0.6 mol.%, less than or equal to 0.4 mol.%, or less than or equal to 0.2 mol.%. In some further embodiments, the glass composition can comprise PbO in an amount: 0.0 mol.% to 5.0 mol.%, 0.0 mol.% to 4.4 mol.%, 0.0 mol.% to 2.0 mol.%, 0.0 mol.% to 1.0 mol.%, 0.4 mol.% to 5.0 mol.%, 0.4 mol.% to 2.0 mol.%, 0.4 mol.% to 1.0 mol.%, 0.6 mol.% to 2.0 mol.%, 1.0 mol.% to 5.0 mol.%, 1.0 mol.% to 4.0 mol.%, 1.0 mol.% to 2.0 mol.%, 2.0 mol.% to 5.0 mol.%, 2.0 mol.% to 4.6 mol.%, 2.0 mol.% to 4.0 mol.%, 3.0 mol.% to 4.8 mol.%, 3.0 mol.% to 4.0 mol.%, 2 mol.% to 4 mol.%, 1 mol.% to 4 mol.%, or 1 mol.% to 3 mol.%.

[0104] In some embodiments, the glass composition can comprise lithium oxide (Li20) in an amount greater than or equal to 0.0 mol.% to less than or equal to 7.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Li20 in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 1.5 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 5.5 mol.%, greater than or equal to 6.0 mol.%, or greater than or equal to 6.5 mol.%. In some other embodiments, the glass composition can comprise Li20 in an amount: less than or equal to 7.0 mol.%, less than or equal to 6.5 mol.%, less than or equal to 6.0 mol.%, less than or equal to 5.5 mol.%, less than or equal to 4.0 mol.%, less than or equal to 2.0 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, or less than or equal to 0.5 mol.%. In some further embodiments, the glass composition can comprise Li20 in an amount: 0.0 mol.% to 7.0 mol.%, 0.0 mol.% to 5.5 mol.%, 0.0 mol.% to 4.0 mol.%, 0.0 mol.% to 3.5 mol.%, 0.0 mol.% to 0.5 mol.%, 0.5 mol.% to 7.0 mol.%, 0.5 mol.% to 6.0 mol.%, 0.5 mol.% to 4.0 mol.%, 0.5 mol.% to 3.5 mol.%, 1.0 mol.% to 6.0 mol.%, 1.0 mol.% to 4.0 mol.%, 1.5 mol.% to 7.0 mol.%, 1.5 mol.% to 4.0 mol.%, 2.0 mol.% to 7.0 mol.%, 2.0 mol.% to 5.5 mol.%, 2.0 mol.% to 4.0 mol.%, 4.0 mol.% to 6.5 mol.%, 4.0 mol.% to 5.5 mol.%, 0.0 mol.% to 6.0 mol.%, 1.0 mol.% to 3.0 mol.%, or 1.0 mol.% to 4.0 mol.%.

[0105] In some embodiments, the glass composition can comprise sodium oxide (Na20) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise Na20 in an amount greater than or equal to 0.0 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, or greater than or equal to 7.5 mol.%. In some other embodiments, the glass composition can comprise Na20 in an amount less than or equal to 10.0 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, or less than or equal to 2.5 mol.%. In some further embodiments, the glass composition can comprise Na20 in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 7.5 mol.%, from 0.0 mol.% to 5.0 mol.%, from 0.0 mol.% to 2.5 mol.%, from 2.5 mol.% to 10.0 mol.%, from 2.5 mol.% to 7.5 mol.%, from 2.5 mol.% to 5.0 mol.%, from 5.0 mol.% to 10.0 mol.%, from 5.0 mol.% to 7.5 mol.%, from 3.7 mol.% to 6.3 mol.%, from 2.5 mol.% to 7.5 mol.%, or from 2.7 mol.% to 6.6 mol.%.

[0106] In some embodiments, the glass composition can comprise potassium oxide (K20) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise K20 in an amount greater than or equal to 0.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, or greater than or equal to 7.5 mol.%. In some other embodiments, the glass composition can comprise K20 in an amount less than or equal to 10.0 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, or less than or equal to 2.5 mol.%. In some further embodiments, the glass composition can comprise K20 in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 7.5 mol.%, from 0.0 mol.% to 5.0 mol.%, from 0.0 mol.% to 2.5 mol.%, from 2.5 mol.% to 10.0 mol.%, from 2.5 mol.% to 7.5 mol.%, from 2.5 mol.% to 5.0 mol.%, from 5.0 mol.% to 10.0 mol.%, from 5.0 mol.% to 7.5 mol.%, from 1.4 mol.% to 6.5 mol.%, from 3.8 mol.% to 6.8 mol.%, or from 2.0 mol.% to 6.0 mol.%.

[0107] In some embodiments, the glass composition can comprise (Na20 + K20) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise (Na20 + K20) in an amount greater than or equal to 0.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, or greater than or equal to 7.5 mol.%. In some other embodiments, the glass composition can comprise (Na20 + K20) in an amount less than or equal to 10.0 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, or less than or equal to 2.5 mol.%. In some further embodiments, the glass composition can comprise (Na20 + K20) in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 7.5 mol.%, from 0.0 mol.% to 5.0 mol.%, from 0.0 mol.% to 2.5 mol.%, from 2.5 mol.% to 10.0 mol.%, from 2.5 mol.% to 7.5 mol.%, from 2.5 mol.% to 5.0 mol.%, from 5.0 mol.% to 10.0 mol.%, from 5.0 mol.% to 7.5 mol.%, from 1.4 mol.% to 6.5 mol.%, from 3.8 mol.% to 6.8 mol.%, or from 2.0 mol.% to 6.0 mol.%.

[0108] In some embodiments, the glass composition can comprise barium oxide (BaO) in an amount greater than or equal to 0.0 mol.% to less than or equal to 15.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise BaO in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 12.0 mol.%, greater than or equal to 13.0 mol.%, or greater than or equal to 14.0 mol.%. In some other embodiments, the glass composition can comprise BaO in an amount: less than or equal to 15.0 mol.%, less than or equal to 14.0 mol.%, less than or equal to 13.0 mol.%, less than or equal to 12.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 5.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, or less than or equal to 1.0 mol.%. In some further embodiments, the glass composition can comprise BaO in an amount: 0.0 mol.% to 15.0 mol.%, 0.0 mol.% to 14.0 mol.%, 0.0 mol.% to 12.0 mol.%, 0.0 mol.% to 10.0 mol.%, 2.0 mol.% to 14.0 mol.%, 2.0 mol.% to 13.0 mol.%, 2.0 mol.% to 10.0 mol.%, 3.0 mol.% to 13.0 mol.%, 5.0 mol.% to 13.0 mol.%, 5.0 mol.% to 12.0 mol.%, 5.0 mol.% to 10.0 mol.%, 10.0 mol.% to 14.0 mol.%, 6.0 mol.% to 12.0 mol.%, 2.6 mol.% to 14.0 mol.%, or 1.0 mol.% to 7.2 mol.%.

[0109] In some embodiments, the glass composition can comprise magnesium oxide (MgO) in an amount greater than or equal to 0.0 mol.% to less than or equal to 10.0 mol.%, and all ranges and sub-ranges between the values described above. In some embodiments, the glass composition can comprise MgO in an amount greater than or equal to 0.0 mol.%, greater than or equal to 0.5 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 1.5 mol.%, greater than or equal to 2.5 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 7.5 mol.%, greater than or equal to 8.5 mol.%, greater than or equal to 9.0 mol.%, or greater than or equal to 9.5 mol.%. In some other embodiments, the glass composition can comprise MgO in an amount less than or equal to 10.0 mol.%, less than or equal to 9.5 mol.%, less than or equal to 9.0 mol.%, less than or equal to 8.5 mol.%, less than or equal to 7.5 mol.%, less than or equal to 5.0 mol.%, less than or equal to 2.5 mol.%, less than or equal to 1.5 mol.%, less than or equal to 1.0 mol.%, or less than or equal to 0.5 mol.%. In some further embodiments, the glass composition can comprise MgO in an amount from 0.0 mol.% to 10.0 mol.%, from 0.0 mol.% to 8.5 mol.%, from 0.0 mol.% to 5.0 mol.%, from 0.0 mol.% to 2.5 mol.%, from 0.5 mol.% to 8.5 mol.%, from 0.5 mol.% to 5.0 mol.%, from 0.5 mol.% to 2.5 mol.%, from 1.0 mol.% to 10.0 mol.%, from 1.0 mol.% to 9.0 mol.%, from 1.5 mol.% to 10.0 mol.%, from 5.0 mol.% to 9.5 mol.%, from 5.0 mol.% to 9.0 mol.%, from 5.0 mol.% to 7.5 mol.%, from 7.5 mol.% to 9.5 mol.%, from 1.4 mol.% to 5.0 mol.%, from 2.5 mol.% to 7.0 mol.%, or from 3.5 mol.% to 7.5 mol.%.

[0110] In some embodiments, the glass composition can comprise strontium oxide (SrO) in an amount greater than or equal to 0.0 mol.% to less than or equal to 35.0 mol.%, and all ranges and sub-ranges between the values described above. In some embodiments, the glass composition can comprise SrO in an amount: greater than or equal to 0.0 mol.%, greater than or equal to 5.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 15.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 25.0 mol.%, or greater than or equal to 30.0 mol.%. In some other embodiments, the glass composition can comprise SrO in an amount: less than or equal to 35.0 mol.%, less than or equal to 30.0 mol.%, less than or equal to 25.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 15.0 mol.%, less than or equal to 10.0 mol.%, or less than or equal to 5.0 mol.%. In some further embodiments, the glass composition can comprise SrO in an amount: 0.0 mol.% to 35.0 mol.%, 0.0 mol.% to 25.0 mol.%, 0.0 mol.% to 15.0 mol.%, 5.0 mol.% to 35.0 mol.%, 5.0 mol.% to 25.0 mol.%, 5.0 mol.% to 15.0 mol.%, 10.0 mol.% to 35.0 mol.%, 10.0 mol.% to 30.0 mol.%, 10.0 mol.% to 25.0 mol.%, 10.0 mol.% to 20.0 mol.%, 15.0 mol.% to 35.0 mol.%, 15.0 mol.% to 30.0 mol.%, 15.0 mol.% to 25.0 mol.%, 20.0 mol.% to 35.0 mol.%, 20.0 mol.% to 30.0 mol.%, 10.0 mol.% to 20.0 mol.%, 0.0 mol.% to 7.5 mol.%, 2.0 mol.% to 7.5 mol.%, 2.5 mol.% to 7.5 mol.%, 5.0 mol.% to 28.0 mol.%, or 19.0 mol.% to 29.0 mol.%.

[0111] In some embodiments, the glass composition can comprise a total amount of divalent metal oxide (RO) in an amount greater than or equal to 0.0 mol% to less than or equal to 40.0 mol%, and all ranges and sub-ranges between the foregoing values. Examples of divalent metal oxides include alkaline earth metal oxides. In some embodiments, the glass composition can comprise RO in an amount: greater than or equal to 0.0 mol%, greater than or equal to 3.0 mol%, greater than or equal to 5.0 mol%, greater than or equal to 8.5 mol%, greater than or equal to 10.0 mol%, greater than or equal to 15.0 mol%, greater than or equal to 20.0 mol%, greater than or equal to 25.0 mol%, or greater than or equal to 30.0 mol%. In some other embodiments, the glass composition can comprise RO in an amount: less than or equal to 40.0 mol%, less than or equal to 35.0 mol%, less than or equal to 30.0 mol%, less than or equal to 25.0 mol%, less than or equal to 20.0 mol%, less than or equal to 15.0 mol%, less than or equal to 10.0 mol%, or less than or equal to 5.0 mol%. In some further embodiments, the glass composition can comprise RO in an amount: 0.0 mol% to 40.0 mol%, 0.0 mol% to 35.0 mol%, 0.0 mol% to 25.0 mol%, 0.0 mol% to 15.0 mol%, 3.0 mol% to 40.0 mol%, 3.0 mol% to 35.0 mol%, 3.0 mol% to 30.0 mol%, 3.0 mol% to 25.0 mol%, 5.0 mol% to 40.0 mol%, 5.0 mol% to 35.0 mol%, 5.0 mol% to 25.0 mol%, 5.0 mol% to 15.0 mol%, 10.0 mol% to 40.0 mol%, 10.0 mol% to 35.0 mol%, 10.0 mol% to 30.0 mol%, 10.0 mol% to 25.0 mol%, 10.0 mol% to 20.0 mol%, 15.0 mol% to 40.0 mol%, 15.0 mol% to 35.0 mol%, 15.0 mol% to 30.0 mol%, 15.0 mol% to 25.0 mol%, 20.0 mol% to 40.0 mol%, 20.0 mol% to 35.0 mol%, 20.0 mol% to 30.0 mol%, 8.5 mol% to 40.0 mol%, 8.5 mol% to 35.0 mol%, 8.5 mol% to 25.0 mol%, 8.5 mol% to 15.0 mol%, 12.0 mol% to 23.0 mol%, 15.0 mol% to 29.0 mol%, or 8.0 mol% to 32.0 mol%.

[0112] In some embodiments, the glass composition can comprise R2O in an amount greater than or equal to 0.0 mol% to less than or equal to 15.0 mol%, and all ranges and sub-ranges between the foregoing values. Examples of monovalent metal oxides R2O include alkali metal oxides. In some embodiments, the glass composition can comprise R2O in an amount greater than or equal to 0.0 mol%, greater than or equal to 1.0 mol%, greater than or equal to 2.0 mol%, greater than or equal to 3.0 mol%, greater than or equal to 5.0 mol%, greater than or equal to 10.0 mol%, greater than or equal to 12.0 mol%, greater than or equal to 13.0 mol%, or greater than or equal to 14.0 mol%. In some other embodiments, the glass composition can comprise R2O in an amount less than or equal to 15.0 mol%, less than or equal to 14.0 mol%, less than or equal to 13.0 mol%, less than or equal to 12.0 mol%, less than or equal to 10.0 mol%, less than or equal to 5.0 mol%, less than or equal to 3.0 mol%, less than or equal to 2.0 mol%, or less than or equal to 1.0 mol%. In some further embodiments, the glass composition can comprise R2O in an amount from 0.0 mol% to 15.0 mol%, from 0.0 mol% to 12.0 mol%, from 1.0 mol% to 15.0 mol%, from 1.0 mol% to 13.0 mol%, from 2.0 mol% to 15.0 mol%, from 2.0 mol% to 13.0 mol%, from 3.0 mol% to 15.0 mol%, from 3.0 mol% to 13.0 mol%, from 3.0 mol% to 10.0 mol%, from 5.0 mol% to 14.0 mol%, from 5.0 mol% to 13.0 mol%, from 5.0 mol% to 12.0 mol%, from 5.0 mol% to 10.0 mol%, from 10.0 mol% to 14.0 mol%, from 2.1 mol% to 9.0 mol%, from 2.5 mol% to 7.4 mol%, or from 7.5 mol% to 13.7 mol%.

[0113] In some embodiments, the glass composition comprises (RE m O n + Ti02+ Nb205+ Zr02+ Bi203+ W03) in an amount greater than or equal to 0.0 mol% to less than or equal to 65.0 mol%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition has (RE m O nThe sum of (RE2O3 + TiO2+ Nb2O5+ ZrO2+ Bi2O3+ WO3) can be: greater than or equal to 0.0 mol%, greater than or equal to 10.0 mol%, greater than or equal to 20.0 mol%, greater than or equal to 25.0 mol%, greater than or equal to 30.0 mol%, greater than or equal to 39.0 mol%, greater than or equal to 40.0 mol%, greater than or equal to 50.0 mol%, or greater than or equal to 60.0 mol%. In some other embodiments, the glass composition has a sum of (RE2O3 + TiO2+ Nb2O5+ ZrO2+ Bi2O3+ WO3) that is greater than or equal to 0.0 mol%, greater than or equal to 10.0 mol%, greater than or equal to 20.0 mol%, greater than or equal to 25.0 mol%, greater than or equal to 30.0 mol%, greater than or equal to 39.0 mol%, greater than or equal to 40.0 mol%, greater than or equal to 50.0 mol%, or greater than or equal to 60.0 mol%. m O n The sum of (RE2O3 + TiO2+ Nb2O5+ ZrO2+ Bi2O3+ WO3) can be: less than or equal to 65.0 mol%, less than or equal to 60.0 mol%, less than or equal to 50.0 mol%, less than or equal to 40.0 mol%, less than or equal to 30.0 mol%, less than or equal to 20.0 mol%, or less than or equal to 10.0 mol%. In some other embodiments, the glass composition has a sum of (RE2O3 + TiO2+ Nb2O5+ ZrO2+ Bi2O3+ WO3) that is less than or equal to 65.0 mol%, less than or equal to 60.0 mol%, less than or equal to 50.0 mol%, less than or equal to 40.0 mol%, less than or equal to 30.0 mol%, less than or equal to 20.0 mol%, or less than or equal to 10.0 mol%. m O n The sum of (RE2O3 + TiO2+ Nb2O5+ ZrO2+ Bi2O3+ WO3) can be: 0.0 mol% to 65.0 mol%, 0.0 mol% to 50.0 mol%, 0.0 mol% to 30.0 mol%, 5.0 mol% to 65.0 mol%, 5.0 mol% to 50.0 mol%, 5.0 mol% to 30.0 mol%, 20.0 mol% to 65.0 mol%, 20.0 mol% to 60.0 mol%, 20.0 mol% to 55.0 mol%, 20.0 mol% to 50.0 mol%, 25.0 mol% to 65.0 mol%, 25.0 mol% to 60.0 mol%, 25.0 mol% to 55.0 mol%, 25.0 mol% to 50.0 mol%, 25.0 mol% to 40.0 mol%, 30.0 mol% to 65.0 mol%, 30.0 mol% to 60.0 mol%, 30.0 mol% to 50.0 mol%, 39.0 mol% to 50.0 mol%, 18.0 mol% to 45.0 mol%, 13.0 mol% to 44.0 mol%, or 13.0 mol% to 40.0 mol%.

[0114] In some embodiments, the glass composition can comprise (Si02+ B203+ Alk20 + MgO + CaO + SrO + BaO + ZnO) in an amount greater than or equal to 0.0 mol.% to less than or equal to 69.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise (Si02+ B203+ Alk20 + MgO + CaO + SrO + BaO + ZnO) in an amount greater than or equal to 0.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 6.0 mol.%, greater than or equal to 10.0 mol.%, greater than or equal to 20.0 mol.%, greater than or equal to 30.0 mol.%, greater than or equal to 40.0 mol.%, greater than or equal to 50.0 mol.%, greater than or equal to 60.0 mol.%, greater than or equal to 63.0 mol.%, greater than or equal to 65.0 mol.%, or greater than or equal to 67.0 mol.%. In some other embodiments, the glass composition can comprise (Si02+ B203+ Alk20 + MgO + CaO + SrO + BaO + ZnO) in an amount less than or equal to 69.0 mol.%, less than or equal to 67.0 mol.%, less than or equal to 65.0 mol.%, less than or equal to 63.0 mol.%, less than or equal to 60.0 mol.%, less than or equal to 50.0 mol.%, less than or equal to 40.0 mol.%, less than or equal to 30.0 mol.%, less than or equal to 20.0 mol.%, less than or equal to 10.0 mol.%, less than or equal to 6.0 mol.%, less than or equal to 4.0 mol.%, or less than or equal to 2.0 mol.%. In some further embodiments, the glass composition can comprise (Si02+ B203+ Alk20 + MgO + CaO + SrO + BaO + ZnO) in an amount from 0.0 mol.% to 69.0 mol.%, from 0.0 mol.% to 60.0 mol.%, from 0.0 mol.% to 20.0 mol.%, from 2.0 mol.% to 69.0 mol.%, from 2.0 mol.% to 60.0 mol.%, from 2.0 mol.% to 20.0 mol.%, from 4.0 mol.% to 69.0 mol.%, from 4.0 mol.% to 63.0 mol.%, from 4.0 mol.% to 40.0 mol.%, from 6.0 mol.% to 63.0 mol.%, from 10.0 mol.% to 63.0 mol.%, from 20.0 mol.% to 65.0 mol.%, from 20.0 mol.% to 60.0 mol.%, from 20.0 mol.% to 40.0 mol.%, from 30.0 mol.% to 69.0 mol.%, from 30.0 mol.% to 60.0 mol.%, from 40.0 mol.% to 60.0 mol.%, from 7.0 mol.% to 6.03 mol.%, from 13.0 mol.% to 45.0 mol.%, or from 15.0 mol.% to 55.0 mol.%.

[0115] In some embodiments, the glass composition can comprise ZnO and Y2O3 in a total amount (ZnO + Y2O3) of greater than or equal to 0.0 mol.% to less than or equal to 5.0 mol.%, and all ranges and sub-ranges between the foregoing values. In some embodiments, the glass composition can comprise (ZnO + Y2O3) in an amount of greater than or equal to 0.0 mol.%, greater than or equal to 0.2 mol.%, greater than or equal to 0.4 mol.%, greater than or equal to 0.6 mol.%, greater than or equal to 1.0 mol.%, greater than or equal to 2.0 mol.%, greater than or equal to 3.0 mol.%, greater than or equal to 4.0 mol.%, greater than or equal to 4.4 mol.%, greater than or equal to 4.6 mol.%, or greater than or equal to 4.8 mol.%. In some other embodiments, the glass composition can comprise (ZnO + Y2O3) in an amount of less than or equal to 5.0 mol.%, less than or equal to 4.8 mol.%, less than or equal to 4.6 mol.%, less than or equal to 4.4 mol.%, less than or equal to 4.0 mol.%, less than or equal to 3.0 mol.%, less than or equal to 2.0 mol.%, less than or equal to 1.0 mol.%, less than or equal to 0.6 mol.%, less than or equal to 0.4 mol.%, or less than or equal to 0.2 mol.%. In some further embodiments, the glass composition can comprise (ZnO + Y2O3) in an amount of 0.0 mol.% to 5.0 mol.%, 0.0 mol.% to 4.4 mol.%, 0.2 mol.% to 4.4 mol.%, 0.4 mol.% to 5.0 mol.%, 0.0 mol.% to 2.0 mol.%, 0.6 mol.% to 2.0 mol.%, 1.0 mol.% to 5.0 mol.%, 1.0 mol.% to 4.6 mol.%, 1.0 mol.% to 4.0 mol.%, 1.0 mol.% to 2.0 mol.%, 2.0 mol.% to 4.6 mol.%, 2.0 mol.% to 4.0 mol.%, 3.0 mol.% to 5.0 mol.%, 3.0 mol.% to 4.8 mol.%, 3.0 mol.% to 4.6 mol.%, 3.0 mol.% to 4.4 mol.%, 3.0 mol.% to 4.0 mol.%, 0.0 mol.% to 3.0 mol.%, 1.0 mol.% to 3.0 mol.%, or 1.0 mol.% to 5.0 mol.%.

[0116] According to embodiments of the disclosure, the glasses described herein have a refractive index n d measured at 587.56 nm. In some examples, the glass has a refractive index n d measured at 587.56 nm of greater than or equal to 1.80, greater than or equal to 1.85, greater than or equal to 1.90, greater than or equal to 1.95, greater than or equal to 2.00, greater than or equal to 2.05, or greater than or equal to 2.10. In some examples, the glass has a refractive index n d: 1.80 to 2.10, 1.85 to 2.10, 1.90 to 2.10, 1.91 to 2.10, 1.95 to 2.10, 2.00 to 2.10, 2.05 to 2.10, 1.80 to 2.05, 1.85 to 2.05, 1.90 to 2.05, 1.91 to 2.05, 1.95 to 2.05, 2.00 to 2.05, 1.80 to 2.00, 1.85 to 2.00, 1.90 to 2.00, 1.91 to 2.00, 1.95 to 2.00, 1.80 to 1.95, 1.85 to 1.95, 1.90 to 1.95, or 1.91 to 1.95, measured at 587.56 nm.

[0117] A lower density corresponds to a lighter weight of an optical element using the glass, given the index of refraction. Size and weight can be important for many types of optical devices, particularly portable optical devices such as augmented reality systems. As noted above, the glasses of the present disclosure have a combination of high index of refraction with low density. According to embodiments of the present disclosure, the glasses described herein have a density d 3 of 5.5 g / cm3or less, measured at 25 °C. RT In some examples, the glasses of the present disclosure can have a density d RT of 5.5 g / cm3or less, 5.3 g / cm3or less, 5.1 g / cm3or less, 4.9 g / cm3or less, 4.8 g / cm3or less, 4.7 g / cm3or less, 4.6 g / cm3or less, or 4.5 g / cm3or less, measured at 25 °C. 3 In some examples, the glasses of the present disclosure can have a density d 3 of 5.5 g / cm3or less, 5.3 g / cm3or less, 5.1 g / cm3or less, 4.9 g / cm3or less, 4.8 g / cm3or less, 4.7 g / cm3or less, 4.6 g / cm3or less, or 4.5 g / cm3or less, measured at 25 °C. 3 In some examples, the glasses of the present disclosure can have a density d 3 of 5.5 g / cm3or less, 5.3 g / cm3or less, 5.1 g / cm3or less, 4.9 g / cm3or less, 4.8 g / cm3or less, 4.7 g / cm3or less, 4.6 g / cm3or less, or 4.5 g / cm3or less, measured at 25 °C. 3 In some examples, the glasses of the present disclosure can have a density d 3 of 5.5 g / cm3or less, 5.3 g / cm3or less, 5.1 g / cm3or less, 4.9 g / cm3or less, 4.8 g / cm3or less, 4.7 g / cm3or less, 4.6 g / cm3or less, or 4.5 g / cm3or less, measured at 25 °C. d In some examples, the glasses of the present disclosure can have a density d 3 of 5.5 g / cm3or less, 5.3 g / cm3or less, 5.1 g / cm3or less, 4.9 g / cm3or less, 4.8 g / cm3or less, 4.7 g / cm3or less, 4.6 g / cm3or less, or 4.5 g / cm3or less, measured at 25 °C. RT In some examples, the glasses of the present disclosure can have a density d d of 5.5 g / cm3or less, 5.3 g / cm3or less, 5.1 g / cm3or less, 4.9 g / cm3or less, 4.8 g / cm3or less, 4.7 g / cm3or less, 4.6 g / cm3or less, or 4.5 g / cm3or less, measured at 25 °C. 3 In some examples, the glasses of the present disclosure can have a density d 3 of 5.5 g / cm3or less, 5.3 g / cm3or less, 5.1 g / cm3or less, 4.9 g / cm3or less, 4.8 g / cm3or less, 4.7 g / cm3or less, 4.6 g / cm3or less, or 4.5 g / cm3or less, measured at 25 °C. RT

[0118] In some embodiments, the glasses of the present disclosure can be characterized by an index of refraction n d and a density d RT :

[0119] n d ​(1.000 + 0.19*d RT )>0.000(I)(a)

[0120] wherein the refractive index n d is measured at a wavelength of 587.56 nm, and the density d RT is measured at 25°C (in g / cm 3 ).

[0121] In some embodiments, the glasses of the present disclosure can be characterized by a refractive index n d and a density d RT :

[0122] n d (1.03 + 0.19*d RT )>0.000(I)(b)

[0123] wherein the refractive index n d is measured at a wavelength of 587.56 nm, and the density d RT is measured at 25°C (in g / cm 3 ).

[0124] In some embodiments, the glasses are characterized by high transmission. Generally, the higher the transmission of the glass, the longer the optical path for transmission at a given optical loss, which can improve optical performance in many applications. High refractive index glasses typically contain at least one species that absorbs a portion of the optical light (e.g., Ti02and Nb205), particularly light in the blue and near-UV regions of the electromagnetic spectrum. In embodiments of the present disclosure, the transmission of the glass can be characterized by different wavelengths ranging from about 300 nm to about 2300 nm. In some applications, high transmission in the visible and near-UV range (blue light region) is particularly desirable. Achieving high transmission in the blue light in high refractive index glasses can be challenging. High levels of Ti02and / or Nb205, which are typically used in glasses to increase the refractive index, tend to decrease transmission in the near-UV region and shift the UV cutoff to higher wavelengths. For internal transmission in the blue light (taking into account Fresnel losses), a sample having an internal transmission equal to or greater than 90% at a wavelength of 460 nm for a thickness of 10 mm can be considered acceptable; an internal transmission equal to or greater than 95% can be considered good; and an internal transmission equal to or greater than 97% can be considered excellent.

[0125] In some embodiments, the glasses can be characterized by a refractive index n d (587.56 nm measurement) and a transmission index T i :

[0126] n d –(2.055–0.36*T i )≥0.000(II)(a)

[0127] In the formula, the transmittance index T is determined according to the following equation (III). i :

[0128]

[0129] In the formula, each oxide listed in equation (III) refers to the amount of oxide in the glass, expressed as mole%. Transmittance index T i It is the mole fraction of colorless refractive index enhancers (La2O3, Gd2O3, and ZrO2) relative to the sum of the five refractive index enhancers (La2O3, Gd2O3, ZrO2, Nb2O5, and TiO2). T was found... i The value is related to the blue light transmittance of the high-refractive-index, low-density glass disclosed herein.

[0130] Figure 1 The transmittance index Ti and the magnitude λ are shown according to equation (III). 70％ The relationship between them. The value λ 70％ This refers to the minimum wavelength corresponding to 70% or higher total transmittance for a glass sample in sheet form with a thickness of 10 mm. Lower λ... 70％ The values ​​typically correspond to a higher wavelength range where the glass sample has high internal transmittance, and therefore a lower λ. 70％ The value usually corresponds to a higher overall transmittance of the glass sample. Figure 1 The data points in the figure correspond to those taken from U.S. Patents 8,728,963 and 9,643,880. The R values ​​shown in the figure correspond to the Pearson correlation coefficient. U.S. Patent 9,643,880 records the glass composition in cation percentage. To calculate the transmittance index T in mol% according to Equation (III) i Assuming the cation percentage is equivalent to the atomic percentage (excluding oxygen), and converting the cation percentage to the molar percentage of oxides for use in equation (III). Figure 1 As shown, the data confirms the value λ. 70％ Correlation with the transmittance index Ti.

[0131] In some embodiments, the glass can be characterized by a refractive index n that satisfies the following equation (IV). d (Measured at 587.56 nm) and transmittance index T i :

[0132] n d - (2.000 - 0.36*T i ) ≥ 0.000 (IV)

[0133] In some embodiments, the glass composition can have a transmittance index T i [ mole % / mole % ] (determined according to equation (III) [ mole % / mole % ],) and all ranges and sub-ranges therebetween. In some embodiments, the transmittance index T i [ mole % / mole % ] of the glass composition can be: greater than or equal to 0.25, greater than or equal to 0.30, greater than or equal to 0.40, greater than or equal to 0.485, greater than or equal to 0.50, greater than or equal to 0.52, greater than or equal to 0.532, greater than or equal to 0.55, greater than or equal to 0.60, or greater than or equal to 0.70. In some other embodiments, the transmittance index T i [ mole % / mole % ] of the glass composition can be: less than or equal to 0.75, less than or equal to 0.70, less than or equal to 0.60, less than or equal to 0.50. In some further embodiments, the transmittance index T i [ mole % / mole % ] of the glass composition can be: 0.25 to 0.75, 0.25 to 0.60, 0.25 to 0.40, 0.30 to 0.60, 0.30 to 0.50, 0.40 to 0.60, 0.50 to 0.75, 0.60 to 0.75, 0.60 to 0.70, 0.38 to 0.65, 0.39 to 0.74, or 0.50 to 0.71. For a glass sample having a thickness of 10 mm, it was found that a transmittance index T i value of 0.532 or greater corresponds to an acceptable high internal transmittance of approximately 95% or greater in the visible range.

[0134] In some embodiments, the relationship between the refractive index n d -1) / d RT is employed to characterize the relationship between the refractive index n RT and the density d d , where the refractive index n 3 is measured at 5587.56 nm and the density is measured at 25 °C in units of g / cm d . The ratio (n RT -1) / d RT is also referred to as the "refractive power" or "refractive power number". The higher the refractive power number, the higher the refractive index at a given density.

[0135] In some embodiments, the glass can be characterized by a refractive index nd (587.56 nm measured), density d RT (25 °C measured) and transmittance index T i :

[0136] [(n d -1) / d RT ] - (0.262 - 0.115*T i )> 0.000(V)

[0137] where the transmittance index T i is determined according to equation (III) above.

[0138] The refractive index, density and refractive power are properties that can be predicted from the glass composition. Linear regression analysis was performed on comparative glasses that are close in composition space to the exemplary glasses of the present disclosure and on some exemplary glasses to determine equations that can be used to predict the composition dependence of the refractive index n d at 587.56 nm wavelength, the glass density (in g / cm 3 ) at 25 °C and the refractive power of the glass. The following equations (VI), (VII) and (VIII) were obtained from the linear regression analysis and are used to predict the refractive index, density and refractive power of the glass, respectively:

[0139]

[0140]

[0141]

[0142] where P n is a refractive index parameter that predicts the refractive index n d of the glass at 587.56 nm wavelength; P d is a density parameter that predicts the density (in g / cm 3 ) of the glass at 25 °C; and P ref is a refractive power parameter that predicts the refractive power of the glass based on the composition of the glass, where each oxide listed in equations (VI), (VII) and (VIII) refers to the amount of the oxide in the glass expressed as mole %.

[0143] Table 1 below specifies the concentration limits used to derive equations (VI), (VII), and (VIII). Linear regression analysis used to determine equations (VI), (VII), and (VIII) randomly selected glasses for use as a training data set to establish the regression and selected glasses for use as a validation data set to evaluate the ability to interpolate within the predefined compositional limits (as specified in Table 1 below). The training data set of glass compositions (approximately 100 glass compositions per property of interest) that met the criteria specified in Table 1 below and had measured values of the properties of interest were randomly selected from literature data available in the SciGlass glass information database and from the example glasses of the embodiments presented herein. Linear regression analysis was used on the data sets specified above to determine equations (VI), (VII), and (VIII), excluding insignificant variables and outliers. Table 2 below presents the resulting equations (VI), (VII), and (VIII). Another portion of glass compositions that met the same criteria were used as a validation set to evaluate the ability to interpolate within the predefined compositional limits, corresponding to the standard deviations specified in Table 2. An external data set of prior art glass compositions (also randomly selected from the SciGlass glass information database) was used to evaluate the ability to predict specific properties that fall outside the range of the specified compositional limits with reasonable accuracy. Multiple iterations of this process were performed to determine the best variables for each property of interest, corresponding to the regression equations specified in Table 2 above.

[0144] Table 1: Compositional regions used for modeling

[0145]

[0146] Table 2: Property prediction models

[0147]

[0148] Figure 2 Measured density d of some comparative glasses ("comparative glasses") and example glasses ("example glasses") RT (25°C measurements in g / cm3) 3 as a function of the density parameter P d As shown by the data in Figure 2 , the compositional dependence of the density parameter P d for most glasses has an error of ±0.12 g / cm3 3 in the range of the measured density d RT . Figure 3 Measured refractive index n of some comparative glasses ("comparative glasses") and example glasses ("example glasses") d (measured at 587.56 nm) as a function of the refractive index parameter P nof the function. As shown by the data in Figure 3 For most glasses, the composition dependence of the refractive index parameter P n has an error in the measured refractive index n d of ±0.019 units. Figure 4 are measured refractive indices n d (587.56 nm measurement) minus one divided by measured density (25 °C measurement in g / cm 3 ) ((n d -1) / d RT , ("refractive power") versus the refractive power parameter P ref . As shown by the data in Figure 4 For most glasses, the composition dependence of the refractive power parameter P ref has an error in the measured refractive power values of ±0.003 units.

[0149] Tables 3-5 below specify concentration limits representative of some embodiments of the present disclosure.

[0150] According to another embodiment of the present disclosure, the glasses herein can have a refractive index parameter P n and a density parameter P d that satisfy one or more of the following equations (IX) and (X):

[0151] P n - (1.000 + 0.19*P d )> 0.000 (IX)

[0152] P n - (1.03 + 0.19*P d )> 0.000 (X)

[0153] where P n is the refractive index parameter determined according to equation (VI) and P d is the density parameter determined according to equation (VII).

[0154] According to another embodiment of the present disclosure, the glasses herein can have a refractive index parameter P n and a transmittance index T i that satisfy one or more of the following equations (XI)(a) and (XI)(b):

[0155] P n - (2.055 - 0.36*T i )> 0.000 (XI)(a)

[0156] P n - (2.1 - 0.36*T i )> 0.000 (XI)(b)

[0157] where P n is the refractive index parameter determined according to equation (VI), and T i is the transmittance index determined according to equation (III).

[0158] According to embodiments of the disclosure, the glasses herein can have a refractive power parameter P ref and a transmittance index T i satisfying equation (XII) as follows:

[0159] P ref - (0.262 - 0.115*T i )> 0.000 (XII)

[0160] where P ref is the refractive power parameter determined according to equation (VIII), and T i is the transmittance index determined according to equation (III).

[0161] In some embodiments, the glasses can be characterized as having good glass forming ability, which can be assessed as resistance to devitrification during cooling. As discussed above, the glass forming ability can be numerically measured by determining the critical cooling rate of the melt (i.e., the minimum cooling rate at which the melt forms glass without crystallization). According to one embodiment, the glass can be characterized as having a critical cooling rate of less than or equal to 300°C / minute, and in some instances less than or equal to 100°C / minute. In some embodiments, the glasses of the disclosure can be characterized by the ability to cool from 1100°C to 500°C in air in 2.5 minutes without crystallization. Glasses characterized by such glass forming ability are compatible with a press molding process.

[0162] Table 3 below shows an exemplary glass A of the disclosure according to some embodiments of the disclosure. Table 3 identifies the component combinations according to some embodiments of the disclosure and their respective amounts. The exemplary glass A in Table 3 can include additional components according to any aspect of the disclosure described herein in an amount of no more than 0.5 mole %.

[0163] Table 3: Exemplary Glass A

[0164] Component Amount (mole %) La2O3 15.0 mole % to 50.0 mole % B2O3 9.0 mole % to 33.0 mole % TiO2 0.0 mole % to 40.0 mole % ZrO2 0.0 mole % to 13.5 mole % [Nb2O5] 0.0 mole % to 12.0 mole % [Y2O3] 0.0 mole % to 3.0 mole % [Ta2O5] 0.0 mole % to 1.5 mole % ZnO 0.0 mole % to 0.8 mole % Li2O 0.0 mole % to 0.5 mole %

[0165] The exemplary glass A in Table 3 can also have a ratio of Si02 / (B203+ Si02) greater than or equal to 0.05 and less than or equal to 0.95, expressed in mole percent of each oxide.

[0166] The exemplary glass A according to some embodiments of the disclosure can also have a transmittance index T i where the transmittance index T i is determined according to equation (III).

[0167] The exemplary glass A according to some embodiments can also satisfy one or more of the following equations (IX) and (X):

[0168] P n - (1.000 + 0.19*P d )> 0.000 (IX)

[0169] P n - (1.03 + 0.19*P d )> 0.000 (X)

[0170] where P n is the refractive index parameter determined according to equation (VI) and P d is the density parameter determined according to equation (VII).

[0171] The exemplary glass A according to some embodiments can also satisfy one or more of the following equations (I)(a) and (I)(b):

[0172] n d - (1.000 + 0.19*d RT )> 0.000 (I)(a)

[0173] n d - (1.03 + 0.19*d RT )> 0.000 (I)(b)

[0174] where n d is the refractive index measured at 587.56 nm and d RT is the density measured at 25 °C (in g / cm 3 ).

[0175] Table 4 below shows exemplary glasses B according to some embodiments of the disclosure. Table 4 identifies combinations of components according to some embodiments of the disclosure and their respective amounts. The exemplary glasses B in Table 4 can include additional components according to any aspect of the disclosure described herein in an amount not greater than 0.5 mole percent.

[0176] Table 4: Exemplary Glass B

[0177]

[0178]

[0179] The exemplary glass B in Table 4 may also contain 0.0 to 1.0 atomic% of fluorine. In some embodiments, the exemplary glass B in Table 4 may also contain 50.0 mol% or less of the sum of (SiO2 + B2O3).

[0180] Exemplary glass B according to some embodiments of this disclosure may also have a sum of 69.0 mol% or less (SiO2+B2O3+Alk2O+MgO+CaO+SrO+BaO+ZnO), where Alk2O is the total content of alkali metal oxides. Exemplary glass B according to some embodiments may also have 25.0 mol% or more (RE m O n The sum of (+TiO2+Nb2O5+ZrO2+Bi2O3+WO3), where RE m O n This refers to the total content of rare earth metal oxides. Exemplary glass B, according to some embodiments, may also contain greater than or equal to 8.5 mol% of divalent metal oxides RO.

[0181] Exemplary glass B according to some embodiments may also satisfy one or more of the following equations (XI)(a) and (XI)(b):

[0182] P n –(2.055–0.36*T i )>0.000 (XI)(a)

[0183] P n –(2.1–0.36*T i )>0.000 (XI)(b)

[0184] In the formula, P n The refractive index parameter is determined according to equation (VI), and T i It is the transmittance index determined according to equation (III).

[0185] Exemplary glass B according to some embodiments may also satisfy one or more of the following equations (II)(a) and (II)(b):

[0186] n d –(2.055–0.36*T i )≥0.000 (II)(a)

[0187] n d –(2.1–0.36*T i )≥0.000 (II)(b)

[0188] In the formula, n d The refractive index was measured at 587.56 nm, and T... i It is the transmittance index determined according to equation (III).

[0189] Table 5 below shows exemplary glass C of the present disclosure according to some embodiments of the present disclosure. Table 5 identifies the combinations of components and their respective amounts according to embodiments of the present disclosure. The exemplary glass C in Table 5 may contain additional components according to any aspect of the present disclosure described herein.

[0190] Table 5: Exemplary Glass C

[0191]

[0192]

[0193] The exemplary glass C in Table 5 may also contain 0.0 to 1.0 atomic% of fluorine. In some embodiments, the exemplary glass C in Table 5 may also contain 45.0 mol% or less of the sum of (SiO2 + B2O3). The exemplary glass C in Table 5 may also contain 2.0 mol% or less of the sum of (Y2O3 + ZnO).

[0194] In some embodiments, the exemplary glass C may also contain a total content of 0.0 mol% to 25.0 mol% of divalent metal oxides (RO). In some embodiments, the exemplary glass C may also contain a total content of 0.0 mol% to 15.0 mol% of monovalent metal oxides (R2O).

[0195] The exemplary glass C according to embodiments of this disclosure may also have a transmittance index T of 0.25 to 0.75. i Furthermore, it can also satisfy the following equation (XII):

[0196] P ref –(0.262–0.115*T i )>0.000(XII)

[0197] In the formula, P ref It is the refractive power parameter determined according to equation (VIII), and T i It is the transmittance index determined according to equation (III).

[0198] In some embodiments, the exemplary glass C may also satisfy the following equation (V):

[0199] [(n d –1) / d RT ]–(0.262–0.115*T i >0.000(V)

[0200] In the formula, n d The refractive index was measured at 587.56 nm, and T... i It is the transmittance index determined according to equation (III).

[0201] Embodiments of this disclosure may provide glass with the following properties: a high refractive index n of 1.80 or higher. d and less than or equal to 5.5 g / cm 3 The density (measured at 25°C) is combined with high transmittance (especially for blue light). In some embodiments, the glass of this disclosure can provide a higher density and refractive index compared to glass with similar density. d This glass offers improved glass-forming capabilities compared to some existing borosilicate glasses with similar transmittance values. In some embodiments, the glass provides improved glass-forming capabilities compared to glass with similar refractive indices (n). d And / or improved light transmittance in the visible region of the spectrum, which is comparable to or improved with respect to existing technology glasses in terms of density characteristics.

[0202] Glass transmittance is at least partly based on the compositional components and / or processes used to form the glass. In a manufacturing setting where process parameters have been determined / optimized, the transmittance of the glass becomes substantially composition-dependent. It is not desirable to be limited by any theory, but it is believed that components (e.g., TiO2 and Nb2O5) may decrease the blue light transmittance of the glass, especially when used at high concentrations. However, components (e.g., TiO2 and Nb2O5) can be used to increase the refractive index of the glass without correspondingly and undesirably increasing the glass density. Thus, in some embodiments, components (e.g., TiO2 and Nb2O5) can be added at adaptive concentrations to provide the desired refractive index and density and also to provide glass with an acceptable level of blue light transmittance. Other oxides (e.g., ZrO2, La2O3, Gd2O3, and in some cases, other rare earth metal oxides) can also be used to increase the refractive index of the glass described herein. It has been found that adding these oxides can produce glass with the desired blue light transmittance. However, these oxides may also increase density, which is undesirable for some applications. High concentrations of some of these oxides can also reduce the glass-forming ability of the composition. For example, these oxides may increase the liquidus temperature and / or cause crystalline phases containing these oxides to precipitate from the glass melt at high temperatures. Among the oxides ZrO2, La2O3, Gd2O3, TiO2, and Nb2O5, ZrO2 has been observed to have the greatest effect on the liquidus temperature in some compositions, while having the least effect on the blue light transmittance of the glass. Therefore, attempts to increase the refractive index and / or decrease the density can have undesirable effects on the glass-forming ability of the composition. Embodiments of this disclosure can provide glasses that offer the high refractive index n required for many applications, such as augmented reality devices, virtual reality devices, mixed reality devices, and / or glasses. d An acceptable balance between density (measured at 25°C) and blue light transmittance characteristics.

[0203] Example

[0204] The following examples illustrate the various features and advantages provided by this disclosure, and they do not in any way constitute a limitation of the invention or the appended claims.

[0205] Both the exemplary and comparative glasses were prepared by melting relatively pure oxide materials. Table 6 below lists some of the typical unspecified elements found in the oxides used in the preparation of the exemplary and comparative glasses described herein.

[0206] Table 6: Oxide Raw Materials and Corresponding Uncertain Element Levels

[0207]

[0208] To prepare glass samples, approximately 15 grams of each sample (target substance content greater than 99.99% by weight) was melted from the batch raw material in a platinum or platinum-rhodium crucible (Pt:Rh = 80:20) at approximately 1300°C for 1 hour. Two controlled cooling conditions were applied. In the first condition (referred to as the “15-minute test”), the sample was cooled from 1100°C to 500°C in the furnace over approximately 15 minutes. In the second condition (referred to as the “2.5-minute test”), the sample was cooled from 1100°C to 500°C in the furnace over approximately 2.5 minutes. Temperature readings were obtained either directly from the furnace temperature or using an IR camera with a calibrated scale. The first condition (15-minute test) approximately corresponds to a cooling rate of up to 300°C / min at a temperature of 1000°C, and the second test condition (2.5-minute test) approximately corresponds to a cooling rate of up to 600°C / min at a temperature of 1000°C (closer to this temperature, the cooling rate is close to its maximum). As the temperature decreases, the cooling rate also decreases significantly. For example... Figure 5 Typical schemes for the first and second cooling methods are shown. No chemical analysis was performed on the test samples because similar samples prepared by independent melting were chemically analyzed by XRF (X-ray fluorescence, for all oxides except B2O3) and ICP (inductively coupled plasma mass spectrometry, for B2O3). These analyses yielded deviations of the major components (e.g., Nb2O5) relative to the feed composition within ±2.0 wt%, which corresponds to less than approximately 1 mol%.

[0209] Table 7 below lists the glass composition and properties of exemplary glasses 1-78 according to embodiments of this disclosure. Table 7 includes observations from three devitrification tests (referred to as "Devitrification Test 1", "Devitrification Test 2", and "Devitrification Test 3"). "Devitrification Test 1" relates to the observations of a glass sample molten in a 1-liter crucible under an optical microscope (magnification between 100x and 500x). The following abbreviations "A", "B", "C", and "D" are used to indicate: no crystallization observed ("A"); a very limited number of crystals found under a microscope, typically only one or two spots in the glass, and only at the surface, with more than 98% of the surface being crystal-free ("B"); more crystals at the surface, but more than 90% of the glass surface being crystal-free ("C"); and some crystals in the crucible bulk, with less than 90% of the glass surface being crystal-free ("D"). "Devitrification Test 2" relates to the "15-minute test" cooling protocol described above; "OK" is used to indicate that the glass composition passed this test. "Devitrification Test 3" refers to the "2.5-minute test" cooling protocol described above; "OK" is observed to indicate that the glass composition passed this test.

[0210] Table 7: Exemplary Glass Compositions

[0211]

[0212]

[0213]

[0214]

[0215] Table 7 (continued)

[0216]

[0217]

[0218]

[0219]

[0220] Table 7 (continued)

[0221]

[0222]

[0223]

[0224]

[0225] Table 7 (continued)

[0226]

[0227]

[0228]

[0229]

[0230] Table 7 (continued)

[0231]

[0232]

[0233]

[0234]

[0235] Table 7 (continued)

[0236]

[0237]

[0238]

[0239]

[0240] Table 7 (continued)

[0241]

[0242]

[0243]

[0244]

[0245] Table 7 (continued)

[0246]

[0247]

[0248]

[0249] Table 7 (continued)

[0250]

[0251]

[0252]

[0253] Table 7 (continued)

[0254]

[0255]

[0256]

[0257] Table 8 below lists the glass composition and properties of comparative glass C1-C32.

[0258] Table 8: Composition and properties of comparative glass

[0259]

[0260]

[0261] Table 8 (continued)

[0262]

[0263]

[0264]

[0265] Table 8 (continued)

[0266]

[0267]

[0268]

[0269] Table 8 (continued)

[0270]

[0271]

[0272]

[0273] The reference keys for each comparative glass listed in Table 8 are as follows: [1] CN110510869 (CDGM Glass Ltd.); [2] FR1214486A (LEITZ GMBH ERNST Ltd.); [3] US10287205B2 (CDGM Glass Ltd.); [4] US2004220041 (HIKARI Glass Ltd.); [5] US4584279A (SCHOTT GLASWERKE Ltd.); [6] US5288669A (Corning Ltd.); [7] US6121176A (Corning Ltd.); [8] US7490485B2 (HOYA Ltd.); [9] US9018116B2 (SCHOTT GLASWERKE Ltd.);

[10] US9302930B2 (HOYA Ltd);

[11] US9394194B2 (HOYA Ltd);

[12] US9643880B2 (HOYA Ltd);

[13] WO2006106781 (Japan Glass Co., Ltd.);

[14] WO2012099168A1 (OHARA KK Ltd);

[15] WO2017110304A1.

[0274] Figure 6 The graphs show the total transmittance τ as a function of wavelength for several exemplary glasses (Examples 1-4). Transmittance was measured using an integrating sphere on a Cary 5000 spectrometer with a thickness of 2 mm and wavelengths from 250 nm to 2500 nm (1 nm resolution). Figure 6 As shown, several in the exemplary glass exhibit a λ value of less than 400 nm. 70％And in some cases, λ is less than 390nm or less than 380nm. 70％ .

[0275] Figure 7 The density parameter P of some exemplary glasses and some comparative glasses is shown. d With refractive index parameter P n The relationship diagram is shown. The exemplary glasses (solid circles) are Examples 1 to 5 and 38 to 50 from Table 7. The comparative example glasses (hollow circles) are Examples C1 to C7 from Table 8. The refractive index parameter P for predicting the refractive index at 587.56 nm is determined according to Equation (VI). n Density parameter P d The room temperature density is predicted and determined according to equation (VII). Figure 7 All exemplary and comparative glass examples shown have the characteristics specified in Table 9 below. In Table 9, if present, the input "No restrictions" means that it is not considered a restriction when selecting the composition. Figure 7 In this context, some of the components listed above may be labeled for better visibility.

[0276] Table 9: Figure 7 Limitations of the glass composition shown

[0277] Amount Unit Minimum Maximum La2O3 mole % 15 50 B2O3 mole % 9 33 TiO2 mole % 0 40 Zr02 mole % 0 13.5 [Nb2O5] mole % 0 12 [Y2O3] mole % 0 3 [Ta2O5] mole % 0 1.5 ZnO mole % 0 0.8 Li2O mole % 0 0.5 SiO2 / (SiO2+B2O3) mole % 0.05 0.95 [CAT i ]]> 0.532 No limit

[0278] The comparative glass examples listed above were selected from known glasses that have the characteristics specified in Table 9, and have a comparable density parameter P. d It has the highest refractive index P in the numerical case. n .

[0279] Figure 7 The line shown, corresponding to the equation y = 1.00 + 0.19*x, provides a visual representation of the differences between the comparative example glass having the characteristics specified in Table 9 and the exemplary glasses 1 to 5 and 38 to 50 according to this disclosure. Figure 7 It can be seen that, Figure 7 The exemplary glass (solid circle) mentioned herein falls above the line y = 1.00 + 0.19*x, and there is no comparative example glass (hollow circle) falling above the line y = 1.00 + 0.19*x, where y corresponds to the refractive index parameter P. n And x corresponds to the density parameter P. d In other words, Figure 7 Some of the exemplary glasses presented satisfy the following equation (IX), and there are no comparative example glasses that satisfy the following equation (IX):

[0280] P n–(1.000+0.19*P d )>0.000 (IX)

[0281] from Figure 7 It can also be seen that, Figure 7 Some of the exemplary glass examples presented fall above the line y = 1.03 + 0.19*x, and there is no comparative example glass falling above the line y = 1.03 + 0.19*x, where y corresponds to the refractive index parameter P. n And x corresponds to the density parameter P. d In other words, Figure 7 The exemplary glass presented herein satisfies the following equation (X), and no comparative glass satisfies the following equation (X):

[0282] P n –(1.03+0.19*P d )>0.000 (X)

[0283] Figure 7 The data shown illustrates that, under the conditions specified in Table 9 above, some exemplary glasses from this disclosure have a comparable density parameter P. d In numerical terms, it has a higher refractive index parameter P compared to the best comparative glass that meets the same conditions. n Numerical values. This can be interpreted as, in prediction, that these exemplary glasses, in the glass described, have a relatively high room temperature density d. RT Value (measured at 25℃, g / cm³) 3 In the case of ), it has the highest refractive index n measured at 587.56 nm. d Numerical value. In other words, in terms of prediction, Figure 7 The exemplary glass shown provides a high refractive index n among known glasses having the properties specified in Table 9. d With low density d at room temperature RT An improvement to the combination.

[0284] Figure 8 The density d of some exemplary glass and some comparative glass are shown. RT (Measured at 25℃, unit is g / cm³) 3 ) and refractive index n d The relationship between (measured at 587.56 nm) is shown in the diagram. The exemplary glass (solid circle) is from Examples 1 to 5 in Table 7. The comparative glass (hollow circle) is from Examples C1, C3, C4, and C7 to C11 in Table 8. Figure 8 All exemplary and comparative glass examples shown have the characteristics specified in Table 10 below. In Table 10, if applicable, the input "No restrictions" means that it is not considered a restriction when selecting the composition.Figure 8 In this context, some of the components listed above may be labeled for better visibility.

[0285] Table 10: Figure 8 Limitations of the glass composition shown

[0286] Amount Unit Minimum Maximum La2O3 mole % 15 50 [B2O3] mole % 9 33 TiO2 mole % 0 40 ZrO2 mole % 0 13.5 [Nb2O5] mole % 0 12 [Y2O3] mole % 0 3 [Ta2O5] mole % 0 1.5 ZnO mole % 0 0.8 Li2O mole % 0 0.5 SiO2 / (SiO2+B2O3) mole % 0.05 0.95 [CAT i ]]> 0.532 No limit

[0287] The comparative glass examples listed above were selected from known glasses that have the characteristics specified in Table 10 mentioned above, and have a comparable density d. RT Value (measured at 25℃, g / cm³) 3 It has the highest refractive index n in the case of ) d Measured value (measured at 587.56 nm).

[0288] Figure 8 The line shown, corresponding to the equation y = 1.00 + 0.19*x, provides a visual representation of the differences between the comparative example glass having the characteristics specified in Table 10 and the exemplary glasses 1 to 5 according to this disclosure. Figure 8 It can be seen that, Figure 8 The exemplary glass (solid circle) mentioned in the text falls above the line y = 1.00 + 0.19*x, and there is no comparative example glass (hollow circle) falling above the line y = 1.00 + 0.19*x, where y corresponds to n. d And x corresponds to d RT In other words, Figure 8 Some of the exemplary glasses presented satisfy the following equation (I)(a), and there are no comparative example glasses that satisfy the following equation (I)(a):

[0289] n d –(1.000+0.19*d RT )>0.000(I)(a)

[0290] from Figure 8 It can also be seen that, Figure 8 Some of the exemplary glass examples presented fall above the line y = 1.03 + 0.19*x, and there is no comparative example glass falling above the line y = 1.03 + 0.19*x, where y corresponds to the refractive index n. d And x corresponds to density d RT In other words, Figure 8 The exemplary glass presented herein satisfies the following equation (I)(b), and no comparative glass satisfies the following equation (I)(b):

[0291] n d –(1.03+0.19*d RT )>0.000(I)(b)

[0292] Figure 8 The data shown illustrates that, under the conditions specified in Table 10 above, some exemplary glasses from this disclosure have a comparable density d. RT Measured values ​​(measured at 25℃, unit: g / cm³) 3 In the case of [condition], the glass exhibits a higher refractive index n compared to the best comparative glass that meets the same conditions. d Measured value (587.56 nm). This can be interpreted as, based on the measured properties, these exemplary glasses, in the glass at a relatively low d... RT In the case of numerical values, it has the highest n d Numerical value. In other words, in terms of measurement properties, Figure 8 The exemplary glass shown provides a density d in a known glass having the properties specified in Table 10. RT With refractive index n d Improvements to the combination.

[0293] therefore, Figure 7 and 8 The predicted and measured property data shown respectively demonstrate that, compared to the best comparative glass with the properties specified in Tables 9 and 10, some exemplary glasses from this disclosure have a refractive index n d (Measured at 587.56 nm) and density d RT (Measured at 25℃, unit is g / cm³) 3 A better combination of )

[0294] Table 11 below presents Figure 7 and 8 Tables 9 and 10 of the comparative example glasses C1 to C11, as well as the numerical values ​​of all properties specified in equations (IX), (X), (I)(a), and (I)(b), are shown in the figures. Table 8 presents the complete composition of the comparative example glasses. Table 7 presents the complete composition of the exemplary glasses derived from this disclosure and the properties mentioned above.

[0295] Table 11: Comparative Examples of Glass Properties with Characteristics Specified in Tables 9 and 10

[0296]

[0297]

[0298] Table 11 (continued)

[0299]

[0300]

[0301] Figure 9The transmittance index T is shown for some exemplary glasses and some comparative glasses. i With refractive index parameter P n The relationship diagram is shown. The exemplary glass (solid circle) is from Examples 1 and 46 to 73 in Table 7. The comparative glass (hollow circle) is from Examples C23 to C30 in Table 8. The refractive index parameter P for predicting the refractive index at 587.56 nm is determined according to Equation (VI). n The transmittance index T is determined according to equation (III). i . Figure 9 All exemplary and comparative glass examples shown have the characteristics specified in Table 12 below. In Table 12, if applicable, the input "No restrictions" means that it is not considered a restriction when selecting the composition. Figure 9 In this context, some of the components listed above may be labeled for better visibility.

[0302] Table 12: Figure 9 Limitations of the glass composition shown

[0303]

[0304]

[0305] The comparative glass examples listed above were selected from known glasses that have the characteristics specified in Table 12, and have a comparable transmittance index T. i The highest refractive index parameter P is obtained in the numerical case. n .

[0306] Figure 9 The line shown, corresponding to the equation y = 2.055 - 0.36*x, provides a visual representation of the differences between the comparative example glass having the characteristics specified in Table 12 and the exemplary glasses 1 and 46 to 73 according to this disclosure. Figure 9 It can be seen that, Figure 9 The exemplary glass (solid circle) mentioned herein falls above the line y = 2.055 - 0.36*x, and there is no comparative example glass (hollow circle) falling above the line y = 2.055 - 0.36*x, where y corresponds to the refractive index parameter P. n And x corresponds to the transmittance index T i In other words, Figure 9 Some of the exemplary glasses presented satisfy the following equation (XI)(a), and there is no comparative glass that satisfies the following equation (XI)(a):

[0307] P n –(2.055–0.36*T i )>0.000(XI)(a)

[0308] from Figure 9 It can also be seen that, Figure 9 Some of the exemplary glass examples presented fall above the line y = 2.1 - 0.36*x, and there is no comparative example glass falling above the line y = 2.1 - 0.36*x, where y corresponds to the refractive index parameter P. n And x corresponds to the transmittance index T i In other words, Figure 9 The exemplary glass presented herein satisfies the following equation (XI)(b), and no comparative glass satisfies the following equation (XI)(b):

[0309] P n –(2.1–0.36*T i )>0.000(XI)(b)

[0310] Figure 9 The data shown illustrates that, under the conditions specified in Table 12 above, some exemplary glasses from this disclosure exhibit a comparable transmittance index T. i In numerical terms, it has a higher refractive index parameter P compared to the best comparative glass that meets the same conditions. n Numerical value. This can be interpreted as, predicting, that these exemplary glasses, in the glass described above, have a relatively high transmittance index T. i In numerical cases, it has the highest refractive index n at 587.56 nm. d Numerical value. In other words, in terms of prediction, Figure 9 The exemplary glass shown provides a transmittance index T in a known glass having the properties specified in Table 12. i With refractive index n d Improvements to the combination.

[0311] Figure 9 The transmittance index T is shown for some exemplary glasses and some comparative glasses. i The refractive index n measured at 587.56 nm d The relationship diagram is shown. The exemplary glass (solid circle) is Example 1 from Table 7. The comparative glass (hollow circle) is Examples C23 to C27, C29, C31 and C32 from Table 8. Figure 10 All exemplary and comparative glass examples shown have the characteristics specified in Table 13 below. In Table 13, if applicable, the input "No restrictions" means that selection of the composition is not considered a restriction. Figure 10 In this context, some of the components listed above may be labeled for better visibility.

[0312] Table 13: Figure 10 Limitations of the glass composition shown

[0313]

[0314]

[0315] The comparative glass examples listed above were selected from known glasses that have the specified characteristics mentioned in Table 13, and have a comparable transmittance index T. i The refractive index n with the highest measured value in numerical cases d (Measured at 587.56 nm).

[0316] Figure 10 The line shown, corresponding to the equation y = 2.055 - 0.36*x, provides a visual representation of the differences between the comparative example glass having the characteristics specified in Table 13 and the exemplary glass 1 according to this disclosure. Figure 10 It can be seen that, Figure 10 The exemplary glass (solid circle) mentioned herein falls above the line y = 2.055 - 0.36*x, and there is no comparative example glass (hollow circle) falling above the line y = 2.055 - 0.36*x, where y corresponds to the refractive index n. d And x corresponds to the transmittance index T i In other words, Figure 10 Some of the exemplary glasses presented satisfy the following equation (II)(a), and there is no comparative glass that satisfies the following equation (II)(a):

[0317] n d –(2.055–0.36*T i )≥0.000(II)(a)

[0318] from Figure 10 It can also be seen that, Figure 10 Some of the exemplary glass examples presented fall above the line y = 2.1 - 0.36*x, and there is no comparative example glass falling above the line y = 2.1 - 0.36*x, where y corresponds to the refractive index n. d And x corresponds to the transmittance index T i In other words, Figure 10 The exemplary glass presented herein satisfies the following equation (II)(b), and no comparative glass satisfies the following equation (II)(b):

[0319] n d –(2.1–0.36*T i )≥0.000(II)(b)

[0320] Figure 10The data shown illustrates that, under the conditions specified in Table 13 above, some exemplary glasses from this disclosure exhibit a comparable transmittance index T. i In the case of measured values, it has a higher refractive index n compared to the best comparative glass that meets the same conditions. d Measured values. This can be interpreted as, based on the measured properties, these exemplary glasses in the glass having a corresponding transmittance index T. i It has the highest refractive index n in the numerical case. d Numerical value. In other words, based on the measured properties, Figure 10 The exemplary glass shown provides a transmittance index T in a known glass having the properties specified in Table 13. i With refractive index n d Improvements to the combination.

[0321] Table 14 below presents Figure 9 and 10 Tables 12 and 13 of the comparative example glasses C23 to C32, as well as the numerical values ​​of all properties specified in equations (XI)(a), (XI)(b), (II)(a), and (II)(b), are shown in the figures. Table 8 presents the complete composition of the comparative example glasses. Table 7 presents the complete composition of the exemplary glasses derived from this disclosure and the properties mentioned above.

[0322] Table 14: Comparative Examples of Glass Properties with Characteristics Specified in Tables 12 and 13

[0323]

[0324]

[0325]

[0326]

[0327] Table 14 (continued)

[0328]

[0329]

[0330] therefore, Figure 9 and 10 The predicted and measured property data shown respectively demonstrate that, compared to the best comparative glass with the properties specified in Tables 12 and 13, some exemplary glasses from this disclosure have a transmittance index T. i With refractive index n d A better combination (measured at 587.56 nm).

[0331] Figure 11 The transmittance index T is shown for some exemplary glasses and some comparative glasses. i With refractive power parameter P ref The relationship diagram is shown. The exemplary glass (solid circle) is from Examples 6 to 37 in Table 7. The comparative glass (hollow circle) is from Examples C12 to C19 in Table 8. Refractive power parameter P ref Predicted (n) d -1) / d RT The ratio (“refractive index”) is given by the formula, where nd is the refractive index measured at 587.56 nm and d is the refractive index. RT This is the density measured at 25℃ (unit: g / cm³). 3 ), and it is determined according to equation (VIII). Figure 11 All exemplary and comparative glass examples shown have the characteristics specified in Table 15 below. In Table 15, if applicable, the input "No restrictions" means that it is not considered a restriction when selecting the composition. Figure 11 In this context, some of the components listed above may be labeled for better visibility.

[0332] Table 15: Figure 11 Limitations of the glass composition shown

[0333]

[0334]

[0335] The comparative glass examples listed above were selected from known glasses having the characteristics specified in Table 15, and having a comparable transmittance index T. i The parameter P has the highest refractive power in numerical cases. ref .

[0336] Figure 11 The line shown, corresponding to the equation y = 0.262 - 0.115*x, provides a visual representation of the differences between the comparative example glass having the characteristics specified in Table 15 and the exemplary glasses 6 to 37 according to this disclosure. Figure 11 It can be seen that, Figure 11 The exemplary glass (solid circle) mentioned herein falls above the line y = 0.262 - 0.115*x, and there is no comparative example glass (hollow circle) falling above the line y = 0.262 - 0.115*x, where y corresponds to the refractive power parameter P. ref And x corresponds to the transmittance index T i In other words, Figure 11 Some of the exemplary glasses presented satisfy the following equation (XII), and there are no comparative example glasses that satisfy the following equation (XII):

[0337] P ref –(0.262–0.115*T i )>0.000(XII)

[0338] Figure 11 The data shown illustrates that, under the conditions specified in Table 15 above, some exemplary glasses from this disclosure exhibit a comparable transmittance index T. i In numerical terms, it has a higher refractive power parameter P compared to the best comparative glass that meets the same conditions. ref Numerical value. This can be interpreted as, predicting, that these exemplary glasses, in the glass described above, have a relatively high transmittance index T. i It has the highest refractive index n in the numerical case. d With density d RT The ratio (n) d -1) / d RT The numerical value of ("refractory power"). In other words, for prediction purposes, Figure 11 The exemplary glass provides a transmittance index T in a known glass having the properties specified in Table 15. i Improvements in combination with refractive power.

[0339] Figure 12 The transmittance index T is shown for some exemplary glasses and some comparative glasses. i With proportion (n) d -1) / d RT The relationship between ("refractive power") is shown in the diagram, where n d The refractive index was measured at 587.56 nm, and d RT This is the density measured at 25℃ (unit: g / cm³). 3 The exemplary glass (solid circle) is from Examples 6, 7 and 18 in Table 7. The comparative glass (hollow circle) is from Examples C3 and C19 to C22 in Table 8. Figure 12 All exemplary and comparative glass examples shown have the characteristics specified in Table 16 below. In Table 16, if applicable, the input "No restrictions" means that it is not considered a restriction when selecting the composition. Figure 12 In this context, some of the components listed above may be labeled for better visibility.

[0340] Table 16: Figure 12 Limitations of the glass composition shown

[0341] Amount Unit Minimum Maximum TiO2 mole % 1 40 B2O3 mole % 1 29 SiO2 mole % 0 32 La2O3 mole % 0 30 CaO mole % 0 15 BaO mole % 0 15 GeO2 mole % 0 10 Al2O3 mole % 0 10 Zr02 mole % 0 7.8 [Nb2O5] mole % 0 7 Li2O mole % 0 4 mole % RO 0 25 [R2O] mole % 0 15 F mole % 0 1 SiO2 + B2O3 Atomic % mole % 45 [Y2O3 + ZnO] No limit 0 2 [CAT i ]]> 0.25 0.75

[0342] The comparative glass examples listed above were selected from known glasses that have the specified characteristics mentioned in Table 16, and have a comparable transmittance index T. i The refractive index n with the highest measured value in numerical cases d With density d RT The ratio (n) d -1) / d RT ("Refractive power").

[0343] mole % The line shown, corresponding to the equation y = 0.262 - 0.115*x, provides a visual representation of the differences between the comparative example glass having the characteristics specified in Table 16 and the exemplary glasses 6, 7, and 18 according to this disclosure. Figure 12 It can be seen that, Figure 12 The exemplary glass (solid circle) mentioned in the text falls above the line y = 0.262 - 0.115 * x, and there is no comparative example glass (hollow circle) falling above the line y = 0.262 - 0.115 * x, where y corresponds to the proportion (n... d -1) / d RT (Refractive power) and x corresponds to the transmittance index T. i In other words, Figure 12 Some of the exemplary glasses presented satisfy the following equation (V), and there are no comparative example glasses that satisfy the following equation (V):

[0344] [(n d –1) / d RT ]–(0.262–0.115*T i )>0.000 (V)

[0345] Figure 12 The data shown illustrates that, under the conditions specified in Table 16 above, some exemplary glasses from this disclosure exhibit a comparable transmittance index T. i In the case of measured values, it has a higher proportion (n) compared to the best comparative glass that meets the same conditions. d -1) / d RT (Refractive power) measurement. This can be interpreted as, based on the measured properties, the refractive power of these exemplary glasses in the glass at a corresponding Trefractive power. i It has the highest ratio (n) in the numerical case. d -1) / d RT In other words, based on the measured properties, Figure 12 The exemplary glass shown provides a transmittance index T in a known glass having the properties specified in Table 16. i With refractive power (ratio (n) d -1) / d RT Improvements to the combination.

[0346] Table 17 below presents Figure 12 and 12 Tables 15 and 16 show the C3 and C12 values ​​and C22 of the comparative example glass, as well as the numerical values ​​of all properties specified in equations (XII) and (V). Table 8 presents the complete composition of the comparative example glass. Table 7 presents the complete composition of the exemplary glass from this disclosure and the properties mentioned above.

[0347] Table 17: Properties of Comparative Glasses Having the Characteristics Specified in Tables 15 and 16

[0348]

[0349]

[0350]

[0351] Table 17 (continued)

[0352]

[0353]

[0354] therefore, Figure 11 Figure 11 and 12 The predicted and measured property data shown respectively demonstrate that, compared to the best comparative glass with the properties specified in Tables 15 and 16, some exemplary glasses from this disclosure have a refractive power (ratio (n)) d -1) / d RT ) and transmittance index T i A better combination.

[0355] This disclosure includes the following non-limiting aspects. To the extent not described, any feature of aspects 1 through 26 may be combined, in whole or in part, with any one or more features of other aspects of this disclosure to form additional aspects, even if such combinations are not described.

[0356] According to a first aspect of this disclosure, the glass comprises: B2O3 in an amount of 9.0 mol% to 33.0 mol%; La2O3 in an amount of 15.0 mol% to 50.0 mol%; SiO2 in an amount greater than 0.0 mol%, wherein the ratio of SiO2 (expressed as mol%) to the sum of SiO2 and B2O3 (expressed as mol%) (SiO2 / (SiO2+B2O3)) is 0.05 to 0.95; and at least one oxide selected from the group consisting of: Nb2O5, TiO2, ZrO2, Y2O3, Li2O, Ta2O5, Al2O3, BaO, Bi2O3, CaO, Er2O3, Gd2O3, K The glass contains 2O, Na2O, Nd2O3, P2O5, PbO, TeO2, WO3, Y2O3, Yb2O3, and ZnO, with the following other requirements: Nb2O5 from 0.0 mol% to 12.0 mol%; TiO2 from 0.0 mol% to 40.0 mol%; ZrO2 from 0.0 mol% to 13.5 mol%; Y2O3 from 0.0 mol% to 3.0 mol%; ZnO from 0.0 mol% to 0.8 mol%; Li2O from 0.0 mol% to 0.5 mol%; and Ta2O5 from 0.0 mol% to 1.5 mol%, wherein the glass has a refractive index parameter P that satisfies the following equation (IX). n and density parameter P d :

[0357] P n –(1.000+0.19*P d )>0.000 (IX)

[0358] In the formula, the refractive index parameter P n Calculate according to the following equation (VI):

[0359]

[0360] And, in the formula, the density parameter P d Calculate according to the following equation (VII):

[0361]

[0362] And among them, the glass has a transmittance index T of 0.532 or greater. i In the formula, the transmittance index T i Calculate according to the following equation (III):

[0363]

[0364] In the formulas, each oxide listed in equations (VI), (VII), and (III) refers to the amount of oxide in the glass, expressed in moles.

[0365] According to the second aspect of this disclosure, the glass of aspect 1 has a refractive index n that satisfies the following equation (I)(a). d and density d RT :

[0366] n d –(1.000+0.19*d RT )>0.000(I)(a)

[0367] In the formula, the refractive index n d It was measured at a wavelength of 587.56 nm, and the density d RT It was measured at 25℃, and the unit is g / cm³. 3 .

[0368] According to the third aspect of this disclosure, the glass of aspect 1 or aspect 2, wherein the transmittance index T i It is 0.550 or greater.

[0369] According to the fourth aspect of this disclosure, a glass of any one of aspects 1-3, wherein the glass contains SiO2 at a concentration of 0.3 mol% to 30.0 mol%.

[0370] According to a fifth aspect of this disclosure, a glass of any one of aspects 1-4, wherein the glass comprises at least one of the following: TiO2 in an amount of 0.3 mol% to 40.0 mol%; ZrO2 in an amount of 0.3 mol% to 10.0 mol%; and Nb2O5 in an amount of 0.3 mol% to 12.0 mol%.

[0371] According to a sixth aspect of this disclosure, the glass of any one of aspects 1-5, wherein the glass comprises at least one of the following: CaO in the range of 0.0 mol% to 30.0 mol%; BaO in the range of 0.0 mol% to 10.0 mol%; WO3 in the range of 0.0 mol% to 10.0 mol%; Na2O in the range of 0.0 mol% to 5.0 mol%; K2O in the range of 0.0 mol% to 5.0 mol%; and SrO in the range of 0.0 mol% to 7.5 mol%.

[0372] According to the seventh aspect of this disclosure, a glass of any one of aspects 1-6, wherein the glass is characterized by its ability to be cooled from 1100°C to 500°C in air within 2.5 minutes without crystallization.

[0373] According to aspect 8 of this disclosure, the glass of any one of aspects 1-7, wherein the glass has a refractive index n of 1.95 or greater. d Measured at a wavelength of 587.56 nm, and 5.3 g / cm³. 3 or even smaller density d RT Measured at 25℃.

[0374] According to the ninth aspect of this disclosure, the glass comprises: 3.0 mol% or more of SiO2; 1.0 mol% or more of B2O3, wherein the sum of (SiO2 + B2O3) is 48.0 mol% or less; the total content (RO) of divalent metal oxides is 8.5 mol% or more; and at least one oxide selected from the group consisting of: Nb2O5, TiO2, ZrO2, Y2O3, Li2O, Ta2O5, and Al2O3. BaO, Bi₂O₃, CaO, Er₂O₃, Gd₂O₃, K₂O, Na₂O, Nd₂O₃, P₂O₅, PbO, TeO₂, WO₃, Y₂O₃, Yb₂O₃, and ZnO, with the following other requirements: Gd₂O₃ from 0.0 mol% to 27.0 mol%; CaO from 0.0 mol% to 32.0 mol%; Li₂O from 0.0 mol% to 7.0 mol%; MgO from 0.0 mol% to 5 mol%. 0.0 mol%; Y₂O₃ from 0.0 mol% to 1.5 mol%; Ta₂O₅ from 0.0 mol% to 0.5 mol%; BaO from 0.0 mol% to 14.0 mol%; CdO from 0.0 mol% to 10.0 mol%; Bi₂O₃ from 0.0 mol% to 20.0 mol%; PbO from 0.0 mol% to 1.0 mol%; HfO₂ from 0.0 mol% to 1.0 mol%; TeO₂ from 0.0 mol% to 5.0 mol%. 0 mol%; Nb₂O₅ from 0.0 mol% to 25.0 mol%; TiO₂ from 0.0 mol% to 18.0 mol%; ZnO from 0.0 mol% to 2.0 mol%; fluorine from 0.0 atom% to 1.0 atom%; the sum of (SiO₂ + B₂O₃ + Alk₂O + MgO + CaO + SrO + BaO + ZnO) is 69.0 mol% or less, where Alk₂O is the total content of alkali metal oxides; and (RE m O n The sum of (TiO2 + Nb2O5 + ZrO2 + Bi2O3 + WO3) is 25.0 mol% or greater, where RE m O n It is the total content of rare earth metal oxides, and among them, the glass has a refractive index parameter P that satisfies the following equation (XI)(a). n and transmittance index T i :

[0375] P n –(2.055–0.36*T i )>0.000(XI)(a)

[0376] In the formula, the refractive index parameter P n Calculate according to the following equation (VI):

[0377]

[0378] And, in the formula, the transmittance index T i Calculate according to the following equation (III):

[0379]

[0380] Furthermore, each oxide listed in equations (VI) and (III) refers to the amount of oxide in the glass, expressed in moles.

[0381] According to aspect 10 of this disclosure, the glass of aspect 9, wherein the glass has a refractive index n measured at a wavelength of 587.56 nm. d And among them, glass satisfies the following equation (II)(a):

[0382] n d –(2.055–0.36*T i )≥0.000(II)(a)

[0383] According to aspect 11 of this disclosure, the glass of aspect 9 has a refractive index n that satisfies the following equation (I)(a). d and density d RT :

[0384] n d –(1.000+0.19*d RT )>0.000(I)(a)

[0385] In the formula, the refractive index n d It was measured at a wavelength of 587.56 nm, and the density d RT It was measured at 25℃, and the unit is g / cm³. 3 .

[0386] According to aspect 12 of this disclosure, a glass of any one of aspects 9-11, wherein the glass comprises: SiO2 of 3.0 mol% to 45.0 mol%; and B2O3 of 1.0 mol% to 45.0 mol%.

[0387] According to aspect 13 of this disclosure, a glass of any one of aspects 9-12, wherein the glass comprises at least one of the following: Nb₂O₅ from 0.0 mol% to 22.0 mol%; La₂O₃ from 0.3 mol% to 30.0 mol%; Gd₂O₃ from 0.0 mol% to 15.0 mol%; and Bi₂O₃ from 0.0 mol% to 10.0 mol%.

[0388] According to aspect 14 of this disclosure, a glass of any one of aspects 9-13, wherein the glass contains a total of (Na2O+K2O) of 0.0 mol% to 10.0 mol%.

[0389] According to aspect 15 of this disclosure, a glass of any one of aspects 9-14, wherein the glass comprises at least one of the following: TiO2 from 0.3 mol% to 18.0 mol%; ZrO2 from 0.3 mol% to 10.0 mol%; Nb2O5 from 0.3 mol% to 15.0 mol%; WO3 from 0.0 mol% to 10.0 mol%; Na2O from 0.0 mol% to 5.0 mol%; K2O from 0.0 mol% to 5.0 mol%; SrO from 0.0 mol% to 7.5 mol%; and Li2O from 0.0 mol% to 4.0 mol%.

[0390] According to the 16th aspect of this disclosure, a glass of any one of aspects 9-15, wherein the glass is characterized by its ability to be cooled from 1100°C to 500°C in air within 2.5 minutes without crystallization.

[0391] According to aspect 17 of this disclosure, a glass of any one of aspects 9-16, wherein the glass has a refractive index n of 1.95 or greater. d Measured at a wavelength of 587.56 nm, and 5.3 g / cm³. 3 or even smaller density d RT Measured at 25℃.

[0392] According to aspect 18 of this disclosure, the glass comprises: TiO2 from 1.0 mol% to 40.0 mol%; B2O3 from 1.0 mol% to 29.0 mol%; SiO2 from 0.0 mol% to 32.0 mol%, wherein the sum of (SiO2 + B2O3) is 45.0 mol% or less; and at least one oxide selected from: Nb2O5, ZrO2, La2O3, Y2O3, Li2O, Al2O3, BaO, Bi2O3, CaO, Er2O3, Gd2O3, Na2O, Nd2O3, P2O5, PbO, WO3, Y2O3, Yb2O3, and ZnO, with other required conditions being: La2O3 from 0.0 mol% to 30.0 mol%; ZrO2 from 0.0 mol% to 32.0 mol%. The glass comprises 0.0 mol% to 7.8 mol% of Nb2O5; 0.0 mol% to 7.0 mol% of CaO; 0.0 mol% to 15.0 mol% of BaO; 0.0 mol% to 15.0 mol% of Li2O; 0.0 mol% to 3.5 mol% of GeO2; 0.0 mol% to 10.0 mol% of Al2O3; 0.0 atom% to 1.0 atom% of fluorine; the sum of (Y2O3+ZnO) is 0.0 mol% to 2.0 mol%; the total content of divalent metal oxides (RO) is 0.0 mol% to 40.0 mol%; and the total content of monovalent metal oxides (R2O) is 0.0 mol% to 15.0 mol%, wherein the glass has a transmittance index T of 0.25 to 0.75. i And among them, the glass has a refractive power parameter P that satisfies the following equation (XII). ref and transmittance index T i :

[0393] P ref –(0.262–0.115*T i )>0.000(XII)

[0394] In the formula, the refractive power parameter P ref Calculate according to the following equation (VIII):

[0395]

[0396] And, in the formula, the transmittance index T i Calculate according to the following equation (III):

[0397]

[0398] Furthermore, each oxide listed in equations (VIII) and (III) refers to the amount of oxide in the glass, expressed in moles.

[0399] According to aspect 19 of this disclosure, aspect 18 has a glass, wherein the glass has a refractive index n measured at a wavelength of 587.56 nm. d and density d measured at 25°C RT (Unit: g / cm³) 3 ), and among them, glass also satisfies the following equation (V):

[0400] [(n d –1) / d RT ]–(0.262–0.115*T i >0.000(V)

[0401] According to aspect 20 of this disclosure, the glass of aspect 18 or 19, wherein the glass has a transmittance index T of 0.485 or greater. i .

[0402] According to aspect 21 of this disclosure, a glass of any one of aspects 18-20, wherein the glass has a refractive index n measured at a wavelength of 587.56 nm. d Furthermore, glass also satisfies the following equation (IV):

[0403] n d –(2.000–0.36*T i ≥0.000(IV)

[0404] According to aspect 22 of this disclosure, a glass of any one of aspects 18-21, wherein the glass contains SiO2 at a concentration of 0.3 mol% to 30.0 mol%.

[0405] According to aspect 23 of this disclosure, a glass of any one of aspects 18-22, wherein the glass comprises at least one of the following: La2O3 in an amount of 0.3 mol% to 30.0 mol%; ZrO2 in an amount of 0.3 mol% to 7.8 mol%; and Nb2O5 in an amount of 0.3 mol% to 7.0 mol%.

[0406] According to aspect 24 of this disclosure, a glass of any one of aspects 18-23, wherein the glass comprises at least one of the following: BaO in the amount of 0.0 mol% to 10.0 mol%; WO3 in the amount of 0.0 mol% to 10.0 mol%; Na2O in the amount of 0.0 mol% to 5.0 mol%; K2O in the amount of 0.0 mol% to 5.0 mol%; SrO in the amount of 0.0 mol% to 7.5 mol%; and Y2O3 in the amount of 0.0 mol% to 3.0 mol%.

[0407] According to aspect 25 of this disclosure, a glass of any one of aspects 18-24, wherein the glass is characterized by its ability to be cooled from 1100°C to 500°C in air within 2.5 minutes without crystallization.

[0408] According to aspect 26 of this disclosure, a glass of any one of aspects 18-25, wherein the glass has a refractive index n of 1.95 or greater. d Measured at a wavelength of 587.56 nm, and 5.3 g / cm³. 3 or even smaller density d RT Measured at 25℃.

[0409] Many changes and modifications can be made to the embodiments described above in this disclosure without significantly departing from the spirit and principles of this disclosure. All such changes and modifications are intended to be included herein, fall within the scope of this disclosure, and are protected by the appended claims.

[0410] Within the scope not yet described, different features of various aspects of this disclosure may be combined and used as needed. A particular feature not explicitly shown or described in any aspect of this disclosure is not to be construed as being impermissible, but rather as being done for the sake of brevity and conciseness of description. Thus, various features of different aspects may be mixed and matched as needed to form new aspects, whether or not the new aspects are explicitly disclosed.

Claims

1. A glass comprising: B203 is 9.0 mole% to 33.0 mole%; La203 is 15.0 mole% to 50.0 mole%; SiO2 is greater than 0.0 mole percent, wherein the ratio of Si02 (expressed as mole%) to the sum of Si02 and B203 (expressed as mole%) (Si02 / (Si02 + B203)) is 0.05 to 0.95; and at least one oxide selected from the group consisting of: Nb205, Ti02, Zr02, Y203, Li20, Ta205, AI203, BaO, Bi203, CaO, Er203, Gd203, K20, Na20, Nd203, P205, PbO, Te02, W03, Yb203, and ZnO, with the proviso that: Nb205 is 0.0 mole% to 12.0 mole%; Ti02 is 0.0 mole% to 40.0 mole%; Zr02 is 0.0 mole% to 13.5 mole%; Y203 is 0.0 mole% to 3.0 mole%; ZnO is 0.0 mole% to 0.8 mole%; Li20 is 0.0 mole% to 0.5 mole%; and Ta205 is 0.0 mole% to 1.5 mole%; and wherein the glass has a refractive index parameter P satisfying the following equation (IX) n and a density parameter P d : P n - (1.000 + 0.19 P d ) > 0.000 (IX) wherein the refractive index parameter P n The calculation is made according to the following equation (VI): and wherein the density parameter P d The calculation is made according to the following equation (VII): and wherein the glass has a transmittance index T of 0.532 or more i wherein the transmittance index T i is calculated according to the following equation (III): wherein each oxide listed in equation (VI), equation (VII), and equation (III) refers to the amount of the oxide in the glass, expressed as mole%.

2. The glass of claim 1, wherein, The glass is characterized by the ability to cool from 1100 °C to 500 °C in air in 2.5 minutes without crystallization.

3. The glass of claim 1 or 2, wherein, The glass has a refractive index n of 1.95 or more d measured at a wavelength of 587.56 nm, and a density d of 5.3 g / cm 3 or less RT measured at 25 °C.

4. A glass comprising: Si02 is 3.0 mole% or more; B2O3 is 1.0 mol% or more, wherein, the sum of (Si02 + B203) is 48.0 mole% or less; the total content of divalent metal oxides (RO) is 8.5 mole% or more; and at least one oxide selected from the group consisting of: Nb205, Ti02, Zr02, Y203, Li20, Ta205, AI203, BaO, Bi203, CaO, Er203, Gd203, K20, Na20, Nd203, P205, PbO, Te02, W03, Yb203, and ZnO, with the proviso that: Gd203 is 0.0 mole% to 27.0 mole%; CaO is 0.0 mole% to 32.0 mole%; Li20 is 0.0 mole% to 7.0 mole%; MgO is 0.0 mole% to 5.0 mole%; Y203 is 0.0 mole% to 1.5 mole%; Ta205 is 0.0 mole% to 0.5 mole%; BaO is 0.0 mole% to 14.0 mole%; CdO is 0.0 mole% to 10.0 mole%; Bi203 is 0.0 mole% to 20.0 mole%; PbO is 0.0 mole% to 1.0 mole%; Hf02 is 0.0 mole% to 1.0 mole%; Te02 is 0.0 mole% to 5.0 mole%; Nb205 is 0.0 mole% to 25.0 mole%; Ti02 is 0.0 mole% to 18.0 mole%; ZnO is 0.0 mole% to 2.0 mole%; fluorine is 0.0 atomic % to 1.0 atomic %; the sum of (SiO2+ B2O3+ Alk2O+ MgO+ CaO+ SrO+ BaO+ ZnO) is 69.0 mol% or less, where Alk2O is the total content of alkali metal oxides; and (RE m O n + TiO2 + Nb2O5 + ZrO2 + Bi2O3+ WO3) is 25.0 mol% or more, where RE m O n is the total content of rare earth metal oxides, and The glass has a refractive index parameter P satisfying the following equation (IX) (a) n and a transmittance index T i : P n - (2.055 - 0.36 T i ) > 0.000 (XI)(a) wherein the refractive index parameter P n The calculation is made according to the following equation (VI): and In the formula, the transmittance index T i The calculation is made according to the following equation (III): and each oxide listed in equation (VIII) and equation (III) refers to the amount of oxide in the glass expressed in mol%.

5. The glass of claim 4, wherein, The glass has a refractive index n satisfying the following equation (I) (a) d and a density d RT : n d – (1.000 + 0.19 d RT ) > 0.000 (I)(a) wherein the refractive index n d is measured at a wavelength of 587.56 nm, and the density d RT is measured at 25 °C in g / cm 3 .

6. The glass of claim 4 or 5, wherein, Glass with a refractive index n of 1.95 or greater d Measured at a wavelength of 587.56 nm, and 5.3 g / cm³. 3 or even smaller density d RT Measured at 25°C.

7. A glass comprising: TiO2is 1.0 mol% to 40.0 mol%; B2O3is 1.0 mol% to 29.0 mol%; SiO2 is 0.0 mole % to 32.0 mole %, wherein, the sum of (SiO2+ B2O3) is 45.0 mol% or less; and at least one oxide selected from the group consisting of: Nb2O5, ZrO2, La2O3, Y2O3, Li2O, Al2O3, BaO, Bi2O3, CaO, Er2O3, Gd2O3, Na2O, Nd2O3, P2O5, PbO, WO3, Yb2O3, and ZnO, with the proviso that: La2O3is 0.0 mol% to 30.0 mol%; ZrO2is 0.0 mol% to 7.8 mol%; Nb2O5is 0.0 mol% to 7.0 mol%; CaO is 0.0 mol% to 15.0 mol%; BaO is 0.0 mol% to 15.0 mol%; Li2O is 0.0 mol% to 3.5 mol%; GeO2is 0.0 mol% to 10.0 mol%; Al2O3is 0.0 mol% to 10.0 mol%; fluorine is 0.0 atomic % to 1.0 atomic %; the sum of (Y2O3+ ZnO) is 0.0 mol% to 2.0 mol%; the total content of divalent metal oxides (RO) is 0.0 mol% to 40.0 mol%; and the total content of monovalent metal oxides (R2O) is 0.0 mol% to 15.0 mol%; and wherein the glass has a transmittance index T of 0.25 to 0.75 i and wherein the glass has a refractive power parameter P satisfying the following equation (XII) ref and a transmittance index T i : P ref - (0.262 - 0.115 T i ) > 0.000 (XII) wherein the refractive power parameter P ref The calculation is made according to the following equation (VIII): and In the formula, the transmittance index T i The calculation is made according to the following equation (III): and each oxide listed in equation (VIII) and equation (III) refers to the amount of oxide in the glass expressed in mol%.

8. The glass of claim 7, wherein, The glass has a refractive index n measured at a wavelength of 587.56 nm d and a density d measured at 25 °C RT (unit: g / cm 3 ), and wherein the glass further satisfies the following equation (V): [(n d – 1) / d RT ] – (0.262– 0.115 T i ) > 0.000 (V).

9. The glass of claim 7 or 8, wherein, The glass has a refractive index n measured at a wavelength of 587.56 nm of 1.5 d and wherein the glass further satisfies the following equation (IV): n d – (2.000 – 0.36 T i ) ≥ 0.000 (IV).

10. The glass of any of claims 7-9, wherein, The glass has a refractive index n of 1.95 or more d measured at a wavelength of 587.56 nm, and a density d of 5.3 g / cm3or less 3 measured at a wavelength of 587.56 nm, and a density d of 5.3 g / cm3or less RT measured at 25 °C.

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