US3786365A
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Laser materials from calcium fluoride - rare earth fluoride expanded lattice structures
Assignee: Raytheon Co
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Filing: 1972-04-26
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Granted: 1974-01-15
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Expires: 1992-04-26
Abstract
Abstract Stimulated emission at the approximate wavelengths of 840 nm, 1860 nm, 2050 nm, 2690 nm, and 2830 nm is obtained from birefrigent laser single crystals of calcium fluoride and the fluorides selected from the trivalent rare earth elements. Each crystal has a structure which deviates from the cubic lattice structure of calcium fluoride and tends toward the hexagonal lattice structure of the rare earth fluorides. The deivation in crystal structure is generally produced by increasing the percent by weight of the rare earth fluoride in excess of 3% and up to 50% of the crystalline solution. Examples of the fluorescent composition include CaF2:xErF3:yYbf3:zTmF3:wHoF3, where x varies from 3% to 50%, y varies from 0% to 3%, z varies from 0% to 3% and w varies from 0% to 3% (all percent by weight). Other rare earth ions, having absorption bands which overlap the output spectum of the pumping means over a wide region, may be used in place of erbium ions.
Inventors
- 👤 M Robinson
- 👤 D Devor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:51
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/16; C; C30; C30B; C30B11/00; C30B29/00; C30B29/10; C30B29/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
A laser system as in claim 1 wherein the ions of said rare earth fluorides consist essentially of trivalent erbium and wherein the percentage by weight of said erbium fluoride is about 12.5 percent and further including temperature control means coupled to said expanded lattice structure for providing the temperature of said expanded lattice structure at 298* K whereby the wavelength of the coherent radiation is produced at approximately 2690 nanometers.
Claim 2
Dependent Claim
88 words
A laser system as in claim 1 wherein the ions of said rare earth fluorides comprise trivalent erbium and trivalent thulium and wherein the percentage by weight of said erbium fluoride is 10 to 23 percent and the percentage by weight of said thulium fluoride is approximately 0.5 percent and further including temperature control means coupled to said expanded lattice structure for providing the temperature thereof at about 100* K + or - 30* K whereby the wavelength of the coherent radiatIon is produced at about 840 nanometers.
Claim 3
Dependent Claim
38 words
A laser system as in claim 1 wherein one ion of said rare fluorides is trivalent holmium and further including temperature control means coupled to said expanded lattice structure for providing the laser wavelength at approximately 2830 nanometers.
Claim 4
Dependent Claim
56 words
A laser system as in claim 1 wherein at least one ion of said rare earth fluorides is trivalent thulium and further including temperature control means coupled to said structure for providing the temperature thereof at about 100* K + or - 50* K whereby the wavelength of the coherent radiation is produced at 1860 nanometers.
Claim 5
Dependent Claim
82 words
A laser system as in claim 1 wherein the ions of said rare earth fluorides consist of erbium, ytterbium, thulium and holmium and further including temperature control means coupled to said structure for providing the specified temperature thereof at about 298* K and about 100* K + or - 30* K to produce cross relaxation and energy transfer to said holmium ions to cause a laser transition is said holmium ions at the respective wavelengths of approximately 2060 nanometers and 2050 nanometers.
Claim 6
Dependent Claim
70 words
A laser system as in claim 7 wherein the percentage by weight of said erbium fluoride is about 10 to 15 percent, of said ytterbium fluoride is about 1 to 3 percent, of said thulium fluoride is about 1 to 3 percent and of said holmium fluoride is about 0.5 to 3 percent, said temperature control means providing the structure temperature at about 100* K, thus producing continuous coherent radiation.
Claim 7
Dependent Claim
133 words
A laser system for producing monochromatic coherent radiation continuously at a wavelength of approximately 2060 nanometers comprising a substantially monocrystalline structure intermediate a cubic structure and a hexagonal structure consisting essentially of about 83.5% calcium fluoride by weight, about 10 % erbium fluoride by weight, about 3% ytterbium fluoride by weight, about 3% thulium fluoride by weight and about 0.5% holmium fluoride by weight, pumping means including an optical pump source optically coupled to said structure for pumping said structure and for producing a population inversion at specified electronic energy levels of ions of said holmium within said momocrystalline structure at the temperature of cold nitrogen gas by means of cross relaxation and energy transfer to said holmium ions and means coupled to said structure for stimulating the coherent radiation at the wavelength.
Claim 8
Dependent Claim
111 words
A laser system for producing a continuous wave, monochromatic coherent radiation comprising a substantially monocrystalline expanded lattice structure intermediate a cubic structure and a hexagonal structure consisting essentially of calcium fluoride, erbium fluoride, ytterbium fluoride, thulium fluoride, and holmium fluoride, pumping means including an optical pump source optically coupled to said structure for pumping said structure and for producing a population inversion at specified electronic energy levels of ions of said holmium within said expanded lattice structure at a specified temperature by means of cross relaxation and energy transfer to said holmium ions, and means coupled to said structure for stimulating the coherent radiation as a result of the population inversion.
Claim 9
Dependent Claim
133 words
A laser system for producing monochromatic coherent radiation at different wavelengths comprising a substantially monocrystalline expanded lattice structure intermediate to a cubic structure and a hexagonal structure consisting essentially of fluoride compounds selected from the group consisting of divalent calcium ion fluorides and the trivalent rare earth ion fluorides, pumping means including an optical pump source coupled to said structure for pumping said structure and for producing energy transfer between specified energy levels of the ions of said rare earth ion fluorides within sAid expanded lattice structure, and means coupled to said structure for stimulating the coherent radiation from said structure at the different wavelengths, at least one ion of said trivalent rare earth ion fluorides having energy levels absorption bands overlapping the output spectrum of said pumping means over a wide region.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |