US3649552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparing high quality rare earth and alkaline earth fluoride single crystals
Assignee: Raytheon Co
•
Filing: 1967-03-31
•
Granted: 1972-03-14
•
Expires: 1987-03-31
Abstract
Abstract LASER QUALITY CRYSTAL OF ALKALINE EARTH AND RARE EARTH FLUORIDES, INCLUDING MIXTURES THEREOF, WHICH ARE PURIFIED OF OXIDES AND OXYFLUORIDES DURING CRYSTAL GROWTH. PURIFICATION IS EFFECTED BY AN ION-EXCHANGE TECHNIQUE AND BY REACTION WITH HYDROGEN FLUORIDE AS SCAVENGER OF OXIDE IMPURITIES PRIMARILY BY MEANS OF A MODIFIED STOCKBARGERTYPE FURNACE. THE MELT IN THE FURNACE S SUBJECTED TO HF GAS THROUGHOUT CRYSTAL GROWTH TO PREVENT HYDROLYSIS CAUSED BY SMALL QUANTITIES OF WATER VAPOR IN THE HF/HE ATMOSPHERE AND/OR GENERATED BY FURNACE OUTGASSING. PURIFICATION METHODS HAVE RESULTED IN CRYSTALS TRANSPARENT TO 0.14 MICRON.
Inventors
- 👤 Morton Robinson
- 👤 Donald M Cripe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:10
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/16; C; C01; C01F; C01F17/00; C01F17/10; C01F17/13; C01F17/20; C01F17/206; C01F17/253; C01F17/265; C01F17/271; C01F17/30; C01F17/36; C30; C30B; C30B11/00; C30B11/002; C30B29/00; C30B29/10; C30B29/12; Y; Y10; Y10S; Y10S117/00; Y10S117/90; Y10S117/906; Y10T; Y10T117/00; Y10T117/10; Y10T117/1024; Y10T117/1092
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |