Rare earth doped oxyhalide laser glass

• US 5,798,306 A
• Filed: 04/14/1997
• Issued: 08/25/1998
• Est. Priority Date: 04/17/1996
• Status: Expired due to Term

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Dickinson, James Edward Jr.
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US08/835,899
• Time in Patent Office: 498 Days
• Field of Search: 372/40, 252/301.4 F, 252/301.4 H, 252/301.4 R, 501/56, 501/57, 501/70, 501/43
• US Class Current: 501/57
• CPC Class Codes: C03C 3/062 with less than 40% silica by weight
• CPC Class Codes: C03C 3/11 containing halogen or nitrogen
• CPC Class Codes: C03C 3/112 containing fluorine
• CPC Class Codes: C03C 4/0071 for laserable glass
• CPC Class Codes: H01S 3/1603 rare earth
• CPC Class Codes: H01S 3/1608 erbium
• CPC Class Codes: H01S 3/17 amorphous, e.g. glass
• CPC Class Codes: H01S 3/173 fluoride glass, e.g. fluorozirconate or ZBLAN [ ZrF4-BaF2-LaF3-AlF3-NaF]

Abstract

The oxyhalide rare earth doped laser glass of the present invention comprises the substitution of fluorine for oxygen in glasses having the general molar batch composition of 50% SiO₂, 25% CaO, 25% Al₂ O₃ to improve the distribution of rare earth dopants in the glass. The general molar batch composition of the invention ranges from approximately 45-70% SiO₂, 15-35% CaO, 10-25% Al₂ O₃, 4-15% Al₂ F₆, and 0.001-2% Er₂ O₃. This substitution of fluorine into the 2SiO₂. Al₂ O₃. CaO glass system provides erbium doped laser glasses having a Er₂ O₃ batch content of 0.01 mole % Er₂ O₃ to 1.2 mole % Er₂ O₃ (500 ppm Er₂ O₃ to 5.68 wt. % Er₂ O₃) which show little to no concentration quenching and exhibit useful fluorescence lifetimes of approximately 6 milliseconds (ms) or greater.

Claims

1. An erbium doped aluminum silicon calcium oxyfluoride laser glass, said glass having a fluorescence lifetime of at least approximately 6 msec, wherein said glass contains 0.005-6 wt. % Er₂ O₃ and 6.2-20 wt. % F.

2. A laser glass as claimed in claim 1, wherein said glass has a concentration of at least 1×

10¹⁷ erbium ions/cm³.

3. A laser glass as claimed in claim 1, wherein said glass has a concentration of at least 1×

10²⁰ erbium ions/cm³.

4. A rare earth doped laser glass, said laser glass having a molar batch composition comprised of

45-70 mole % SiO₂ ;

15-35 mole % CaO;

10-25 mole % Al₂ O₃ ;

4-15 mole % Al₂ F₆ ;

0.001-2 mole % Er₂ O₃.

5. A laser glass as claimed in claim 4, wherein said laser glass has a concentration of at least 1×

10¹⁷ erbium ions/cm³.

6. A laser glass as claimed in claim 4, wherein said glass has a concentration of at least 1×

10²⁰ erbium ions/cm³.

7. A laser glass as claimed in claim 4, wherein said glass contains 6.2-20 wt. % F.

8. A laser glass as claimed in claim 4, wherein said laser glass exhibits a fluorescence lifetime of at least 6 milliseconds.

9. A laser glass having a weight % batch composition comprising:

30-45 wt. % SiO₂ ;

25-45 wt. % Al₂ O₃ ;

10-25 wt. % CaO;

0.005-10 wt. % Er₂ O₃ ; and

7-35 wt. % F, batched as Al₂ F₆

wherein said glass has an analyzed content of at least 6.2-20 wt. % F.

10. A laser glass as claimed in claim 9, wherein

wherein said laser glass exhibits a fluorescence lifetime of at least 6 milliseconds.

11. A laser glass having a weight % batch composition consisting essentially of:

37-40 wt. % SiO₂ ;

30-40 wt. % Al₂ O₃ ;

15-19 wt. % CaO,

0.005-6 wt. % Er₂ O₃ ; and

9-30 wt. % F, batched as Al₂ F₆

wherein said glass has an analyzed content of at least 6.5-15 wt. % F.

12. An aluminum silicon oxyhalide laser glass containing a divalent oxide and doped with a plurality of erbium ions, said erbium ions are contained in a concentration of at least 1×

10¹⁷ ions/cm³, said glass having an analyzed fluorine wt. % content of 6.2-20 wt. % fluorine wherein said glass exhibits a fluorescence lifetime of at least 7.6 ms.

13. A laser glass as claimed in claim 12, wherein said erbium ions are contained in a concentration of at least 1×

10²⁰ ions/cm³.

14. An erbium doped aluminum silicon oxyfluoride laser glass, which contains a divalent oxide and 0.005-10 wt. % Er₂ O₃ and 6.2-20 wt. % F, wherein said glass exhibits a fluorescence lifetime of at least 6 ms.

15. A laser glass as claimed in claim 14, wherein said divalent oxide is CaO.

16. An optical amplifier formed from an erbium doped oxyfluoiride laser glass having a weight % batch composition comprised of 30-45 wt. % SiO₂, 25-45 wt. % Al₂ O₃, 10-25 wt. % CaO, 0.005-10 wt. % Er₂ O₃, wherein said glass has an analyzed content of 6.2-20 wt. % F.

17. A method of inhibiting concentration quenching of a rare earth dopant in a laser glass, said method comprises the steps of providing an erbium silicate laser glass having a batch composition of MO₂, M¹, M²₂ O₃ and Er₂ O₃, where M is Si or Ge, M¹ is an oxide of Zn, an alkali metal or an alkaline earth metal, and M² is Al, Ga, or B, and substituting an oxygen ion in the laser glass with a fluorine ion by replacing a part of an oxide in the batch composition with a fluoride.

22. A method as claimed in claim 17 wherein replacing a part of an oxide in the batch composition with a fluoride comprises replacing Al₂ O₃ with Al₂ F₆.

18. A rare earth doped laser glass, said laser glass having a molar batch composition consisting essentially of:

0.001-2 mole % Er₂ O₃ ;

45-70 mole % MO₂ ;

15-35 mole % M¹ ;

10-25 mole % M²₂ O₃ ;

4-15 mole % Al₂ F₆

wherein M is Si or Ge; and

M¹ is an oxide of Zn, an alkali metal or an alkaline earth metal; and

M² is Al, Ga, or B.

19. A rare earth doped laser glass, said laser glass having a molar batch composition comprised of:

45-70 mole % MO₂ ;

15-35 mole % M¹ ;

10-25 mole % M²₂ O₃ ;

4-15 mole % Al₂ F₆ ;

0.001-2 mole % Er₂ O₃

wherein M is Si or Ge; and

M¹ is an oxide of Zn, an alkali metal or an alkaline earth metal; and

and M² is Al, Ga;

or B.

20. A laser glass as claimed in claim 19 wherein the glass contains 6.2-20 wt. % F.

21. A laser glass as claimed in claim 19 wherein said laser glass exhibits a fluorescence lifetime of at least 6 milliseconds.