Abstract: An optical glass has optical constants represented by a refractive index (nd) of 1.46 to 1.58 and an Abbe's number (?d) of 65 to 74, has excellent hot preform shapeability, low softenability and excellent climate resistance, and comprises, by mol %, 45 to 65% of P2O5, 8 to 19% of Al2O3, 5 to 30% of MgO, 1 to 25% of a total of Li2O, Na2O and K2O, 0 to 16% of B2O3, 0 to 25% of ZnO, 0 to 25% of CaO, 0 to 25% of SrO, 0 to 30% of BaO, 0 to 10% of La2O3, 0 to 10% of Gd2O3, 0 to 10% of Y2O3, 0 to 10% of Yb2O3 and 0 to 10% of Lu2O3, and the total content of the above components of the optical glass is at least 95%.

Abstract: The present invention relates to preferably lead-free and arsenic-free optical glasses, having a refractive index of 1.48?nd?1.56, an Abbe number of 64??d?72, a low transformation temperature (Tg?500° C.) and good ion exchange properties, as well as good chemical resistance and crystallization stability, and comprising the following composition (in % by weight): SiO2 53-58 B2O3 11-15 Al2O3 16-20 Na2O ?0-13 K2O ?0-13 ?M2O ?9-13 F 0.5-4?? The glass may additionally contain standard refining agents. The invention also relates to the use of the optical glasses according to the invention in the application areas of imaging, projection, telecommunications, optical communication technology and/or laser technology.

Abstract: Optical glasses and optical articles comprised of the optical glass are disclosed. One of which comprises, by means of weight percentages, more than 32 percent and not more than 45 percent P2O5, more than 0.5 percent and not more than 6 percent Li2O, more than 5 percent and not more than 22 percent Na2O, 6-30 percent Nb2O5, 0.5-10 percent B2O3, 0-35 percent WO3, 0-14 percent K2O, and 10-24 percent Na2O+K2O, and the total of all the above components is not less than 80 percent.

Abstract: An optical glass having properties of a high refractive index and low dispersion and having both a low sag temperature Ts and a low liquidus temperature L.T., is provided. The optical glass comprises, by % by weight, 25 to 42% of B2O3, 14 to 30% of La2O3, 2 to 13% of Y2O3, 2 to 20 of SiO2, greater than 2% and 9% or less of Li2O, 0.5 to 20% of CaO, 2 to 20% of ZnO, 0 to 8% of Gd2O3, 0 to 8% of ZrO2, Gd2O3+ZrO2 being 0.5 to 12%, the total content thereof being at least 90%, and optionally contains 0 to 5% of Na2O, 0 to 5% of K2O, 0 to 5% of MgO, 0 to 5% of SrO, 0 to 10% of SrO, 0 to 10% of BaO, 0 to 5% of Ta2O, 0 to 5% of Al2O3, 0 to 5% of Yb2O3, 0 to 5% of Nb2O5, 0 to 2% of As2O3 and 0 to 2% of Sb2O3.

Abstract: The preparation of objects, in particular optical components and/or devices, is described using, as precursors of optical materials, amorphous monolithic aerogels for high-precision mechanical machining.

Abstract: An optical glass has fluorine ion F.sup.- and oxygen ion O.sup.2- as anions. The cations in the glass expressed in terms of fluorides and mol % have the following preferred composite range:______________________________________ PF.sub.5 5.0-30.0% AlF.sub.3 19.0-40.0% CaF.sub.2 28.0-56.0% MgF.sub.2 0-20.0% SrF.sub.2 0-9.0% BaF.sub.2 0-18.0% ZnF.sub.2 0-10.0% YF.sub.3 0-13.0% LaF.sub.3 0-7.0% ______________________________________The F.sup.- /O.sup.2- ratio (the ratio of the number of fluorine ions to the number of oxygen ions) in the glass is in the range of 1.4 - 13.0. The specific gravity of glass is not more than 3.6.

Abstract: A fluorophosphate optical glass having optical constants, i.e. a refractive index of 1.45 to 1.54 and an Abbe number of 75 to 90, preferably 75 to 89.5, useful as a lens for an optical instrument to obtain a good quality image, is provided, which has a chemical composition (% by mole) comprising:______________________________________ P.sub.2 O.sub.5 6.8-19.0% Al.sub.2 O.sub.3 1.5-6.0% BaO 0.3-6.6% AlF.sub.3 16.6-26.3% MgF.sub.2 2.5-19.0% CaF.sub.2 8.0-28.0% SrF.sub.2 9.7-35.0% BaF.sub.2 7.9-35.0% NaF 0.5-4.0% Gd.sub.2 O.sub.3 1.0-6.0% Y.sub.2 O.sub.3 0-3.5% La.sub.2 O.sub.3 0-3.5% Yb.sub.2 O.sub.3 0-3.5% sum of Gd.sub.2 O.sub.3, Y.sub.2 O.sub.3, La.sub.2 O.sub.3 and Yb.sub.2 O.sub.3 1.0-6.0% GdF.sub.3 0-2.0% CaO 0-3.5% SrO 0-3.5% ZnO 0-3.5% MgO 0-3.

Abstract: A fluorophosphate optical glass having optical constants, i.e. refractive index (nd) of 1.54 to 1.60 and Abbe number (.nu.d) of 68 to 75 and having abnormal partial dispersion represented by a relative partial dispersion of at least 0.537 is provided, which has a chemical composition (% by weight) comprising:______________________________________ Al(PO.sub.3).sub.3 15-32% Ba(PO.sub.3).sub.2 0-10% Sr(PO.sub.3).sub.2 0-10% Ca(PO.sub.3).sub.2 0-10% Mg(PO.sub.3).sub.2 0-10% sum of metaphosphates 20-32% BaF.sub.2 20-70% SrF.sub.2 5-40% CaF.sub.2 0-15% MgF.sub.2 0-10% AlF.sub.3 0-5% GdF.sub.3 0-5% sum of fluorides 55-75% Gd.sub.2 O.sub.3 5-22% La.sub.2 O.sub.3 0-7% Y.sub.2 O.sub.3 0-10% Yb.sub.2 O.sub.

Abstract: Optical fluorophosphate glass which is based on Mg(PO.sub.3).sub.2, Ca(PO.sub.3).sub.2, Ba(PO.sub.3).sub.2, Al(PO.sub.3).sub.3, MgF.sub.2, CaF.sub.2, SrF.sub.2, AlF.sub.3, BaO and SrO and has a refractive index n.sub.e between 1.515 and 1.546, an Abbe value .nu..sub.e between 75.8 and 77.4 and a positive anomalous partial dispersion value .DELTA..nu..sub.e between 14.85 and 15.15.The glass comprises (in weight-%) 2.4-2.7 Mg; 4.5-4.9 Ca; 15.9-17.6 Sr; 20.2-22.3 Ba; 5.6-6.2 Al; 8.8-9.7 P; 22.0-24.3 F and 15.7-17.4 O. The improved physico-chemical parameters, such as linear expansion coefficient, glass transition temperature T.sub.g, density .zeta., Knoop-hardness HK, etc., are stated. Finally, a production process for this optical glass is described.

Abstract: Optical fluorophosphate glass which is based on Mg(PO.sub.3).sub.2, Ca(PO.sub.3).sub.2, Ba(PO.sub.3).sub.2, Al(PO.sub.3).sub.3, MgF.sub.2, CaF.sub.2, SrF.sub.2, AlF.sub.3, BaO and SrO and has a refractive index n.sub.e between 1.515 and 1.546, an Abbe value .nu..sub.e between 75.8 and 77.4 and a positive anomalous partial dispersion value .DELTA..nu..sub.e between 14.85 and 15.15.The glass comprises (in weight-%) 2.4-2.7 Mg; 4.5-4.9 Ca; 15.9-17.6 Sr; 20.2-22.3 Ba; 5.6-6.2 Al; 8.8-9.7 P; 22.0-24.3 F and 15.7-17.4 O. The improved physico-chemical parameters, such as linear expansion coefficient, glass transition temperature T.sub.g, density .zeta., Knoop-hardness HK, etc., are stated. Finally, a production process for this optical glass is described.

Abstract: Optical fluorophosphate glasses based on Ba(PO.sub.3).sub.2, Al(PO.sub.3).sub.3, alkaline earth metal fluorides and AlF.sub.3 are described which have a refactive index n.sub.e between 1.47 and 1.50, an Abbe-value .nu..sub.e between 85 and 80 and a positive anomalous partial dispersion value .DELTA..nu..sub.e between +17 and +22. They comprise (in wt.-%) 0.5-3 Mg, 8-10 Ca, 12-20 Sr, 9-12 Ba, 7-9 Al, 5-9 P, 8-12 O and 35-38 F. Ti, Na, K and H may additionally be present. The improved physico-chemical parameters (expansion coefficient, glass transition temperature, density, Knoop-hardness) and the transmission characteristics are given, and a process for producing these optical glasses is described.

Abstract: A fluorophosphate optical glass with a low refractive index and low dispersion is provided in stable manner, which has a refractive index nd of 1.42 to 1.47 and an Abbe number .nu.d of 90 to 97 and comprises 3 to 8 mole % of P.sub.2 O.sub.5, 0.1 to 2 mole % of Al.sub.2 O.sub.3, 1 to 7 mole % of BaO, 35.5 to 41 mole % of AlF.sub.3, 8 to 13 mole % of MgF.sub.2, 16 to 26 mole % of CaF.sub.2, 15 to 21 mole % of SrF.sub.2, 3.5 to 10 mole % of BaF.sub.2 and 1 to 6 mole % of NaF.

Abstract: This specification discloses fluophosphate optical glass of low dispersion containing no beryllium and arsenic and having an optical constant nd=1.43-1.48 and .nu.d=85-97 and which can be produced stably and easily.

Abstract: Fluorophosphate glass free of beryllium with a refractive index n.sub.e between 1.40 and 1.46, an Abbe value v.sub.e between 85 and 94 and a high positive anomalous partial dispersion value +.DELTA.v.sub.e between 19 and 28 is described. The glass is melted from a mixture containing as groups of components metaphosphate, fluorides and an alkali fluoroborate in certain proportions expressed in % by weight, in the following manner: the intermixed mixtue is heated to a temperature between 800.degree. and 800.degree. C., the melt refined at a temperature between 900.degree. and 1000.degree. C. for a period of 8 and 25 minutes, homogenized at a temperature between 900.degree. and 1000.degree. C. within a period of time of 5 to 15 minutes, the temperature reduced to a pouring temperature between 575.degree. and 650.degree. C. and the melt poured into casting molds preheated to approximately 320.degree. C., in particular aluminum molds.

Abstract: The present invention is directed to the production of essentially dry alkali metal (R.sup.1) aluminofluorophosphate glasses optionally containing at least one divalent metal (R.sup.2) which exhibits a transition temperature below about 350.degree. C., good chemical durability, resistance to weathering, and glass stability, and which demonstrate the capability of being molded at temperatures below 400.degree. C. into complex shapes. The alkali metal aluminofluorophosphate glasses consist essentially, as analyzed on an atomic basis, between about R.sup.1 AlP.sub.2 F.sub.2 O.sub.6 and R.sup.1 .sub.3.75 AlP.sub.3 F.sub.4 O.sub.9 with the requirement that the components comply with the following atomic ratios:F:Al >2 but <4 (preferred 3.+-.0.5)P:Al >2 but <3R.sup.1 :P >0.5 but <1.24 (preferred >0.75 but <1.1)Those values, expressed in terms of weight percent as analyzed on the oxide basis, convert to the following approximate ranges:R.sup.1.sub.2 O 13-38Al.sub.2 O.sub.3 16-23P.sub.2 O.sub.