US4301426A
Expired / Lapsed
US
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Solid state laser and material
Assignee: United States Department of the Navy
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Filing: 1979-11-19
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Granted: 1981-11-17
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Expires: 1999-11-19
Abstract
Abstract Broadly tunable, c.w. laser action in the ir(infrared) spectral region is obtained from (F 2 + ) A color centers in an alkali halide crystal having F A , F B , F A ', F B ' (F 2 ) A and (F 2 + ) A color centers in a dynamic equilibrium. The laser material is prepared by additively coloring an alkali halide crystal, exposing the colored crystal to light in the high-energy edge (i.e., between 450-300 nm) of the F-center absortion range at a temperature from about 253K to about 300K, cooling the crystal to a temperature not greater than 100K, and re-exposing the crystal to the same light to create a dynamic equilibrium state in which (F 2 + ) A centers are present.
Inventors
- 👤 Irwin Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:11
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/16; H01S3/1681
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
91 words
A laser material for a solid-state tunable laser which comprises an alkali halide crystal with at least one cation impurity selected from the class consisting of lithium, sodium, potassium, rubidium, cesium, calcium, strontium, and barium, said crystal having a crystalographic structure with point defects consisting essentially of (F 2 ) A , (F 2 + ) A , F A , F B , F A ', and F B ' color centers in a state of dynamic equilibrium so that bleaching of (F 2 + ) A centers is avoided.
Claim 2
Dependent Claim
91 words
A laser material for a solid-state tunable laser which comprises an alkali halide crystal with at least one cation impurity selected from the class consisting of lithium, sodium, potassium, rubidium, cesium, calcium, strontium, and barium, said crystal having a crystalographic structure with point defects consisting essentially of (F 2 ) A , (F 2 + ) A , F A , F B , F A ', and F B ' color centers in a state of dynamic equilibrium so that bleaching of (F 2 + ) A centers is avoided.
Claim 3
Dependent Claim
24 words
The laser material of claim 1 wherein said alkali halide is selected from the class consisting of sodium, potassium, and rubidium chloride and fluoride.
Claim 4
Dependent Claim
32 words
The laser material of claim 2 wherein said cation impurity is selected from the class consisting of lithium, sodium and potassium and is smaller than the alkali metal of said alkali halide.
Claim 5
Dependent Claim
19 words
The laser material of claim 2 wherein alkali halide is selected from potassium chloride, potassium fluoride, and sodium fluoride.
Claim 6
Dependent Claim
14 words
The laser material of claim 1 wherein said alkali halide is an alkali iodide.
Claim 7
Dependent Claim
22 words
The laser material of claim 5 wherein said alkali halide is selected from the class consisting of sodium, potassium, and rubidium iodide.
Claim 8
Dependent Claim
21 words
The laser material of claim 6 wherein said alkali halide is selected from the class consisting of potassium and rubidium iodide.
Claim 9
Independent Claim
113 words
A method for generating (F 2 +) A color centers in an alkali halide crystal which comprises: additively coloring said crystal; quenching said crystal to a temperature from about 253K to about 300K; irradiating said crystal with light in approximately the high-energy portion of the F-center absorption band to produce, F A , F B , F 2 , and (F 2 ) A color centers until the F 2 and (F 2 ) A concentrations are maximized; cooling said crystal to a temperature of about 100K or less; irradiating said crystal with light in approximately the high-energy portion of the F-center absorption band to produce (F 2 + ) A color centers.
Claim 10
Independent Claim
113 words
A method for generating (F 2 +) A color centers in an alkali halide crystal which comprises: additively coloring said crystal; quenching said crystal to a temperature from about 253K to about 300K; irradiating said crystal with light in approximately the high-energy portion of the F-center absorption band to produce, F A , F B , F 2 , and (F 2 ) A color centers until the F 2 and (F 2 ) A concentrations are maximized; cooling said crystal to a temperature of about 100K or less; irradiating said crystal with light in approximately the high-energy portion of the F-center absorption band to produce (F 2 + ) A color centers.
Claim 11
Dependent Claim
36 words
The method of claim 8 wherein irradiating said crystal to produce F A , F B , F 2 , and (F 2 ) A color centers is done at a temperature from 292 to 297K.
Claim 12
Dependent Claim
27 words
The method of claim 9 wherein irradiating said crystal to produce (F 2 + ) A color centers is done at a temperature from 50 to 90K.
Claim 13
Dependent Claim
127 words
In an apparatus for amplifying light by stimulated emission of radiation the improvement which comprises: a laser medium, said laser medium being said alkali halide crystal of claim 1; means for exposing said crystal with light in the infrared absorption band of the (F 2 + ) A center of said crystal to produce a population inversion in the energy configuration of said crystal; an optical cavity, in which said crystal is located, said cavity being capable of resonating at the fluorescence bands of (F 2 + ) A centers and thus capable of stimulating the emission of coherent radiation from said color centers; means for illuminating said crystal with light absorbed in the F-band spectral region; and means for maintaining said crystal at 100K or lower.
Claim 14
Dependent Claim
27 words
The apparatus of claim 11 wherein said cavity has a three-mirror, astigmatically compensated configuration and said laser medium is located at the beam waist of said cavity.
Claim 15
Dependent Claim
20 words
The apparatus of claim 12 wherein said apparatus further comprises a means for tuning said emission from said color centers.
Claim 16
Dependent Claim
18 words
The apparatus of claim 13 wherein alkali halide is selected from potassium chloride, potassium fluoride, and sodium fluoride.
Claim 17
Dependent Claim
18 words
The apparatus of claim 12 wherein alkali halide is selected from potassium chloride, potassium fluoride, and sodium fluoride.
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) | 1984-11-16 | 1985-05-18 | 1985-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-16 | 1989-05-18 | 1989-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-16 | 1993-05-18 | 1993-11-17 | $7700.00 | Window Closed / Lapsed |