Fluorophosphate glass and process of making same

Claim 2

In a process of producing a fluorophosphate glass having an index of refraction n e within the range of from about 1.5753 to about 1.6915, an Abbe number ν e within the range of from about 41.2 to 69.7, and a relatively high positive anomalous partial dispersion, comprising the steps of a. melting a mixture essentially consisting of the following components, in weight percent: Fluoride component (a) 0.1% to 1.5% of magnesium fluoride MgF 2 , 0.1% to 1.5% of calcium fluoride CaF 2 , 0% to 15.0% of strontium fluoride SrF 2 , 0% to 25.0% of barium fluoride BaF 2 , 0% to 10.0% of aluminum fluoride AlF 3 , and 0.1% to 1.5% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides in said mixture not exceeding 38% and the total sum of all fluorides in said mixture not exceeding 45%. Metaphosphate component (b) 8.0% to 12.0% of aluminum metaphosphate Al(PO 3 ) 2 , 3.0% to 25.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 10.0% to 18.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 50%; Barium oxide component (c)

Claim 3

0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , 0% to 4.0% of titanium dioxide TiO 2 , and 0% to 20.0% of niobium pentoxide Nb 2 O 5 ; b. homogenizing the molten mixture at a temperature within the range of from about 1000°C. to about 1100°C. with stirring; c. cooling said molten mixture to about 800°C.; and, d. pouring said mixture into preheated molds.

Claim 4

0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , 0% to 4.0% of titanium dioxide TiO 2 , and 0% to 20.0% of niobium pentoxide Nb 2 O 5 ; b. homogenizing the molten mixture at a temperature within the range of from about 1000°C. to about 1100°C. with stirring; c. cooling said molten mixture to about 800°C.; and, d. pouring said mixture into preheated molds.

Claim 5

The process of claim 1, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.4 % to 0.5 % of magnesium fluoride MgF 2 , 0.5 % to 0.6 % of calcium fluoride CaF 2 , 0 % to 13.0 % of strontium fluoride SrF 2 , 0 % to 22.0 % of barium fluoride BaF 2 , 0 % to 8.0 % of aluminum fluoride AlF 3 , and 0.5 % to 0.6 % of lanthanum fluoride LaF 3 ; the total sum of the alkaline earth metal fluorides in said mixture not exceeding the sum of 35 % and the total sum of all fluorides not exceeding 43 %; Metaphosphate component (b) 9.0 % to 10.0 % of aluminum metaphosphate Al(PO 3 ) 3 , 4.0 % to 23.0 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.0 % to 15.0 % of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 47 %; Barium oxide component (c) 10.0 % to 52.0 % of barium oxide BaO; and Additional oxide component (d) 0 % to 15.0 % of boron trioxide B 2 O 3 , 0 % to 8.0 % of germanium dioxide GeO 2 , 0 % to 2.0 % of titanium dioxide TiO 2 , and 0 % to 18.0 % of niobium pentoxide Nb 2 O 5 .

Claim 6

The process of claim 1 in which the mixture consists of the following components, in weight percent: Fluoride component (a)

Claim 7

44 % of magnesium fluoride MgF 2 , 0.53 % of calcium fluoride CaF 2 , 0 % to 12.2 % of strontium fluoride SrF 2 , 0 % to 21.5 % of barium fluoride BaF 2 , 0 % to 7.5 % of aluminum fluoride AlF 3 , and 0.53 % of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides being at least 0.97 % and not exceeding 34.67 % and the total sum of all fluorides in said mixture being at least 1.5 % and not exceeding 42.7 %; Metaphosphate component (b) 9.3 % of aluminum metaphosphate Al(PO 3 ) 3 , 4.5 % to 22.5 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.8 % to 14.8 % of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture being at least 28.6 % and not exceeding 46.6 %; Barium oxide component (c) 10.7 % to 51.9 % of barium oxide BaO; and Additional oxide component (d) 0 % to 15.0 % of boron trioxide B 2 O 3 , 0 % to 7.5 % of germanium dioxide GeO 2 , 0 % to 1.5 % of titanium dioxide TiO 2 , and 0 % to 18.0 % of niobium pentoxide Nb 2 O 5 .

Claim 8

44 % of magnesium fluoride MgF 2 , 0.53 % of calcium fluoride CaF 2 , 0 % to 12.2 % of strontium fluoride SrF 2 , 0 % to 21.5 % of barium fluoride BaF 2 , 0 % to 7.5 % of aluminum fluoride AlF 3 , and 0.53 % of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides being at least 0.97 % and not exceeding 34.67 % and the total sum of all fluorides in said mixture being at least 1.5 % and not exceeding 42.7 %; Metaphosphate component (b) 9.3 % of aluminum metaphosphate Al(PO 3 ) 3 , 4.5 % to 22.5 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.8 % to 14.8 % of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture being at least 28.6 % and not exceeding 46.6 %; Barium oxide component (c) 10.7 % to 51.9 % of barium oxide BaO; and Additional oxide component (d) 0 % to 15.0 % of boron trioxide B 2 O 3 , 0 % to 7.5 % of germanium dioxide GeO 2 , 0 % to 1.5 % of titanium dioxide TiO 2 , and 0 % to 18.0 % of niobium pentoxide Nb 2 O 5 .

Claim 9

A batch composition for making fluorophosphate glass having an index of refraction n e within the range of from about 1.5753 to about 1.6915, an Abbe number ν e within the range of from about 41.2 to 69.7, and a relatively high positive anomalous partial dispersion, said composition essentially consisting of the following components, in weight percent: Fluoride component (a) 0.1% to 1.5% of magnesium fluoride MgF 2 , 0.1% to 1.5% of calcium fluoride CaF 2 , 0% to 15.0% of strontium fluoride SrF 2 , 0% to 25.0% of barium fluoride BaF 2 , 0% to 10.0% of aluminum fluoride AlF 3 , and 0.1% to 1.5% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides in said mixture not exceeding 38% and the total sum of all fluorides in said mixture not exceeding 45%; Metaphosphate component (b) 8.0% to 12% of aluminum metaphosphate Al(PO 3 ) 2 , 3.0% to 25.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 10.0% to 18.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 50%; Barium oxide component (c) 8.0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , 0% to 4.0% of titanium dioxide TiO 2 , and 0% to 20.0% of niobium pentoxide Nb 2 O 5 .

Claim 10

A batch composition for making fluorophosphate glass having an index of refraction n e within the range of from about 1.5753 to about 1.6915, an Abbe number ν e within the range of from about 41.2 to 69.7, and a relatively high positive anomalous partial dispersion, said composition essentially consisting of the following components, in weight percent: Fluoride component (a) 0.1% to 1.5% of magnesium fluoride MgF 2 , 0.1% to 1.5% of calcium fluoride CaF 2 , 0% to 15.0% of strontium fluoride SrF 2 , 0% to 25.0% of barium fluoride BaF 2 , 0% to 10.0% of aluminum fluoride AlF 3 , and 0.1% to 1.5% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides in said mixture not exceeding 38% and the total sum of all fluorides in said mixture not exceeding 45%; Metaphosphate component (b) 8.0% to 12% of aluminum metaphosphate Al(PO 3 ) 2 , 3.0% to 25.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 10.0% to 18.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 50%; Barium oxide component (c) 8.0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , 0% to 4.0% of titanium dioxide TiO 2 , and 0% to 20.0% of niobium pentoxide Nb 2 O 5 .

Claim 11

The composition of claim 4, in which the mixture consists of the following components, in weight percent: Fluoride component (a)

Claim 12

4 % to 0.5 % of magnesium fluoride MgF 2 , 0.5 % to 0.6 % of calcium fluoride CaF 2 , 0 % to 13.0 % of strontium fluoride SrF 2 , 0 % to 22.0 % of barium fluoride BaF 2 , 0 % to 8.0 % of aluminum fluoride AlF 3 , and 0.5 % to 0.6 % of lanthanum fluoride LaF 3 ; the total sum of the alkaline earth metal fluorides in said mixture not exceeding the sum of 35 % and the total sum of all fluorides not exceeding 43 %; Metaphosphate component (b) 9.0 % to 10.0 % of aluminum metaphosphate Al(PO 3 ) 3 , 4.0 % to 23.0 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.0 % to 15.0 % of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 47 %; Barium oxide component (c) 10.0 % to 52.0 % of barium oxide BaO; and Additional oxide component (d) 0 % to 15.0 % of boron trioxide B 2 O 3 , 0 % to 8.0 % of germanium dioxide GeO 2 , 0 % to 2.0 % of titanium dioxide TiO 2 , and 0 % to 18.0 % of niobium pentoxide Nb 2 O 5 .

Claim 13

4 % to 0.5 % of magnesium fluoride MgF 2 , 0.5 % to 0.6 % of calcium fluoride CaF 2 , 0 % to 13.0 % of strontium fluoride SrF 2 , 0 % to 22.0 % of barium fluoride BaF 2 , 0 % to 8.0 % of aluminum fluoride AlF 3 , and 0.5 % to 0.6 % of lanthanum fluoride LaF 3 ; the total sum of the alkaline earth metal fluorides in said mixture not exceeding the sum of 35 % and the total sum of all fluorides not exceeding 43 %; Metaphosphate component (b) 9.0 % to 10.0 % of aluminum metaphosphate Al(PO 3 ) 3 , 4.0 % to 23.0 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.0 % to 15.0 % of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 47 %; Barium oxide component (c) 10.0 % to 52.0 % of barium oxide BaO; and Additional oxide component (d) 0 % to 15.0 % of boron trioxide B 2 O 3 , 0 % to 8.0 % of germanium dioxide GeO 2 , 0 % to 2.0 % of titanium dioxide TiO 2 , and 0 % to 18.0 % of niobium pentoxide Nb 2 O 5 .

Claim 14

The composition of claim 4, in which the mixture consists of the following components, in weight percent: Fluoride component (a)

Claim 15

44 % of magnesium fluoride MgF 2 , 0.53 % of calcium fluoride CaF 2 , 0 % to 12.2 % of strontium fluoride SrF 2 , 0 % to 21.5 % of barium fluoride BaF 2 , 0 % to 7.5 % of aluminum fluoride AlF 3 , and 0.53 % of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides being at least 0.97 % and not exceeding 34.67 % and the total sum of all fluorides in said mixture being at least 1.5 % and not exceeding 42.7 %; Metaphosphate component (b) 9.3 % of aluminum metaphosphate Al(PO 3 ) 3 , 4.5 % to 22.5 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.8 % to 14.8 % of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture being at least 28.6 % and not exceeding 46.6 %; Barium oxide component (c) 10.7 % to 51.9 % of barium oxide BaO; and Additional oxide component (d) 0 % to 15.0 % of boron trioxide B 2 O 3 , 0 % to 7.5 % of germanium dioxide GeO 2 , 0 % to 1.5 % of titanium dioxide TiO 2 , and 0 % to 18.0 % of niobium pentoxide Nb 2 O 5 .

Claim 16

44 % of magnesium fluoride MgF 2 , 0.53 % of calcium fluoride CaF 2 , 0 % to 12.2 % of strontium fluoride SrF 2 , 0 % to 21.5 % of barium fluoride BaF 2 , 0 % to 7.5 % of aluminum fluoride AlF 3 , and 0.53 % of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides being at least 0.97 % and not exceeding 34.67 % and the total sum of all fluorides in said mixture being at least 1.5 % and not exceeding 42.7 %; Metaphosphate component (b) 9.3 % of aluminum metaphosphate Al(PO 3 ) 3 , 4.5 % to 22.5 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.8 % to 14.8 % of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture being at least 28.6 % and not exceeding 46.6 %; Barium oxide component (c) 10.7 % to 51.9 % of barium oxide BaO; and Additional oxide component (d) 0 % to 15.0 % of boron trioxide B 2 O 3 , 0 % to 7.5 % of germanium dioxide GeO 2 , 0 % to 1.5 % of titanium dioxide TiO 2 , and 0 % to 18.0 % of niobium pentoxide Nb 2 O 5 .

Claim 17

The composition of claim 4, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.44 % of magnesium fluoride MgF 2 , 0.53 % of calcium fluoride CaF 2 , 12.20 % of strontium fluoride SrF 2 , 7.50 % of aluminum fluoride AlF 3 , and 0.53 % of lanthanum fluoride LaF 3 ; Metaphosphate component (b) 9.30 % of aluminum metaphosphate Al(PO 3 ) 3 , 22.50 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 14.80 % of barium metaphosphate Ba(PO 3 ) 2 ; and Barium oxide component (c) 32.20 % of barium oxide BaO.

Claim 18

The composition of claim 4, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.44 % of magnesium fluoride MgF 2 , 0.53 % of calcium fluoride CaF 2 , 12.20 % of strontium fluoride SrF 2 , 7.50 % of aluminum fluoride AlF 3 , and 0.53 % of lanthanum fluoride LaF 3 ; Metaphosphate component (b) 9.30 % of aluminum metaphosphate Al(PO 3 ) 3 , 22.50 % of magnesium metaphosphate Mg(PO 3 ) 2 , and 14.80 % of barium metaphosphate Ba(PO.sub. 3) 2 ; Barium oxide component (c) 29.20 % of barium oxide BaO; and Additional oxide component (d) 3.00 % of germanium oxide GeO 2 .

Claim 19

A fluorophosphate glass having an index of refraction n e within the range of from about 1.5753 to about 1.6267, an Abbe number ν e within the range of from about 61.4 to about 69.7, and a relatively high positive anomalous partial dispersion, said glass being produced by melting a mixture essentially consisting of the following components, in weight percent: Fluoride component (a) 0.1% to 1.5% of magnesium fluoride MgF 2 , 0.1% to 1.5% of calcium fluoride CaF 2 , 0% to 15.0% of strontium fluoride SrF 2 , 0% to 25.0% of barium fluoride BaF 2 , 0% to 10.0% of aluminum fluoride AlF 3 , and 0.1% to 1.5% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides in said mixture not exceeding 38% and the total sum of all fluorides in said mixture not exceeding 45%; Metaphosphate component (b) 8.0% to 12% of aluminum metaphosphate Al(PO 3 ) 2 , 3.0% to 25.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 10.0% to 18.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 50%; Barium oxide component (c)

Claim 20

A fluorophosphate glass having an index of refraction n e within the range of from about 1.5753 to about 1.6267, an Abbe number ν e within the range of from about 61.4 to about 69.7, and a relatively high positive anomalous partial dispersion, said glass being produced by melting a mixture essentially consisting of the following components, in weight percent: Fluoride component (a) 0.1% to 1.5% of magnesium fluoride MgF 2 , 0.1% to 1.5% of calcium fluoride CaF 2 , 0% to 15.0% of strontium fluoride SrF 2 , 0% to 25.0% of barium fluoride BaF 2 , 0% to 10.0% of aluminum fluoride AlF 3 , and 0.1% to 1.5% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides in said mixture not exceeding 38% and the total sum of all fluorides in said mixture not exceeding 45%; Metaphosphate component (b) 8.0% to 12% of aluminum metaphosphate Al(PO 3 ) 2 , 3.0% to 25.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 10.0% to 18.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 50%; Barium oxide component (c)

Claim 21

0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , and 0% to 4.0% of titanium dioxide TiO 2 .

Claim 22

0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , and 0% to 4.0% of titanium dioxide TiO 2 .

Claim 23

The fluorophosphate glass of claim 9, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.4% to 0.5% of magnesium fluoride MgF 2 , 0.5% to 0.6% of calcium fluoride CaF 2 , 0% to 13.0% of strontium fluoride SrF 2 , 0% to 22.0% of barium fluoride BaF 2 , 0% to 8.0% of aluminum fluoride AlF.sub. 3, and 0.5% to 0.6% of lanthanum fluoride LaF 3 ; the total sum of the alkaline earth metal fluorides in said mixture not exceeding the sum of 35% and the total sum of all fluorides not exceeding 43%; Metaphosphate component (b) 9.0% to 10.0% of aluminum metaphosphate Al(PO 3 ) 3 , 4.0% to 23.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.0% to 15.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 47%; Barium oxide component (c)

Claim 24

0% to 52.0% of barium oxide BaO; and Additional oxide component (d) 0% of boron trioxide B 2 O 3 , 0% to 8.0% of germanium dioxide GeO 2 , 0% to 2.0% of titanium dioxide TiO 2 ,

Claim 25

0% to 52.0% of barium oxide BaO; and Additional oxide component (d) 0% of boron trioxide B 2 O 3 , 0% to 8.0% of germanium dioxide GeO 2 , 0% to 2.0% of titanium dioxide TiO 2 ,

Claim 26

The fluorophosphate glass of claim 9, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.44% of magnesium fluoride MgF 2 , 0.53% of calcium fluoride CaF 2 , 0% to 12.2% of strontium fluoride SrF 2 , 0% to 21.5% of barium fluoride BaF 2 , 0% to 7.5% of aluminum fluoride AlF 3 , and 0.53% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides being at least 0.97% and not exceeding 34.67% and the total sum of all fluorides in said mixture being at least 1.5% and not exceeding 42.7%; Metaphosphate component (b) 9.3% of aluminum metaphosphate Al(PO 3 ) 3 , 4.5% to 22.5% of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.8% to 14.8% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture being at least 28.6% and not exceeding 46.6%; Barium oxide component (c)

Claim 27

7% to 51.9% of barium oxide BaO; and Additional oxide component (d): 0% to 15.0% of boron trioxide B 2 O 3 , 0% to 7.5% of germanium dioxide GeO 2 , 0% to 1.5% of titanium dioxide TiO 2 .

Claim 28

7% to 51.9% of barium oxide BaO; and Additional oxide component (d): 0% to 15.0% of boron trioxide B 2 O 3 , 0% to 7.5% of germanium dioxide GeO 2 , 0% to 1.5% of titanium dioxide TiO 2 .

Claim 29

The fluorophosphate glass of claim 9, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.44% of magnesium fluoride MgF 2 , 0.53% of calcium fluoride CaF 2 , 12.20% of strontium fluoride SrF 2 , 7.50% of aluminum fluoride AlF 3 , and 0.53% of lanthanum fluoride LaF 3 ; Metaphosphate component (b) 9.30% of aluminum metaphosphate Al(PO 3 ) 3 , 22.50% of magnesium metaphosphate Mg(PO 3 ) 2 , and 14.80% of barium metaphosphate Ba(PO 3 ) 2 ; and Barium oxide component (c) 32.20% of barium oxide BaO.

Claim 30

The fluorophosphate glass of claim 9, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.44% of magnesium fluoride MgF 2 , 0.53% of calcium fluoride CaF 2 , 12.20% of strontium fluoride SrF 2 , 7.50% of aluminum fluoride AlF 3 , and 0.53% of lanthanum fluoride LaF 3 ; Metaphosphate component (b) 9.30% of aluminum metaphosphate Al(PO 3 ) 3 , 22.50% of magnesium metaphosphate Mg(PO 3 ) 2 , and 14.80% of barium metaphosphate Ba(PO 3 ) 2 ; Barium oxide component (c) 29.20% of barium oxide BaO; and Additional oxide component (d) 3.00% of germanium oxide GeO 2 .

Claim 31

A fluorophosphate glass having an index of refraction n e , within the range of from about 1.5974 to 1.6915, an Abbe number ν e within the range of from about 41.2 to 62.7 and a relatively high positive anomalous partial dispersion, said glass being produced by melting a mixture essentially consisting of the following components, in weight percent: Fluoride component (a)

Claim 32

A fluorophosphate glass having an index of refraction n e , within the range of from about 1.5974 to 1.6915, an Abbe number ν e within the range of from about 41.2 to 62.7 and a relatively high positive anomalous partial dispersion, said glass being produced by melting a mixture essentially consisting of the following components, in weight percent: Fluoride component (a)

Claim 33

1% to 1.5% of magnesium fluoride MgF 2 , 0.1% to 1.5% of calcium fluoride CaF 2 , 0% to 15.0% of strontium fluoride SrF 2 , 0% to 25.0% of barium fluoride BaF 2 , 0% to 10.0% of aluminum fluoride AlF 3 , and 0.1% to 1.5% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides in said mixture not exceeding 38% and the total sum of all fluorides in said mixture not exceeding 45%; Metaphosphate component (b) 8.0% to 12% of aluminum metaphosphate Al(PO 3 ) 2 , 3.0% to 25.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 10.0% to 18.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 50%; Barium oxide component (c) 8.0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , 0% to 4.0% of titanium dioxide TiO 2 , and 3.0% to 18.0% of niobium pentoxide Nb 2 O 5 .

Claim 34

1% to 1.5% of magnesium fluoride MgF 2 , 0.1% to 1.5% of calcium fluoride CaF 2 , 0% to 15.0% of strontium fluoride SrF 2 , 0% to 25.0% of barium fluoride BaF 2 , 0% to 10.0% of aluminum fluoride AlF 3 , and 0.1% to 1.5% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides in said mixture not exceeding 38% and the total sum of all fluorides in said mixture not exceeding 45%; Metaphosphate component (b) 8.0% to 12% of aluminum metaphosphate Al(PO 3 ) 2 , 3.0% to 25.0% of magnesium metaphosphate Mg(PO 3 ) 2 , and 10.0% to 18.0% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture not exceeding 50%; Barium oxide component (c) 8.0% to 55.0% of barium oxide BaO; Additional oxide component (d) 0% to 17.0% of boron trioxide B 2 O 3 , 0% to 10.0% of germanium dioxide GeO 2 , 0% to 4.0% of titanium dioxide TiO 2 , and 3.0% to 18.0% of niobium pentoxide Nb 2 O 5 .

Claim 35

The fluorophosphate glass of claim 14, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.44% of magnesium fluoride MgF 2 , 0.53% of calcium fluoride CaF 2 , 0% to 12.2% of strontium fluoride SrF 2 , 0% to 21.5% of barium fluoride BaF 2 , 0% to 7.5% of aluminum fluoride AlF 3 , and 0.53% of lanthanum fluoride LaF 3 , the total sum of the alkaline earth metal fluorides being at least 0.97% and not exceeding 34.67% and the total sum of all fluorides in said mixture being at least 1.5% and not exceeding 42.7%; Metaphosphate component (b) 9.3% of aluminum metaphosphate Al(PO 3 ) 3 , 4.5% to 22.5% of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.8% to 14.8% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture being at least 28.6% and not exceeding 46.6%; Barium oxide component (c) 32.2% of barium oxide BaO; and Additional oxide component (d) 0% to 15.0% of boron trioxide B 2 O 3 , 0% to 15.0% of boron trioxide B 2 O 3 , 0% to 7.5% of germanium dioxide GeO 2 , 0% to 1.5% of titanium dioxide TiO 2 , and 3.0% to 18.0% of niobium pentoxide Nb 2 O 5 .

Claim 36

The fluorophosphate glass of claim 15, in which the mixture consists of the following components, in weight percent: Fluoride component (a) 0.44% of magnesium fluoride MgF 2 , 0.53% of calcium fluoride CaF 2 , 12.20% of strontium fluoride SrF 2 , 7.5% of aluminum fluoride AlF 3 , and 0.53% of lanthanum fluoride LaF 3 ; Metaphosphate component (b) 9.3% of aluminum metaphosphate Al(PO 3 ) 3 , 4.5% to 22.5% of magnesium metaphosphate Mg(PO 3 ) 2 , and 11.8% to 14.8% of barium metaphosphate Ba(PO 3 ) 2 , the total sum of the metaphosphates in said mixture being at least 28.6% and not exceeding 46.60%; Barium oxide component (c) 32.2% of barium oxide BaO; and Additional oxide component (d) 3.0% to 18.0% of niobium pentoxide Nb 2 O 5 .