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US3817604A
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Method of focusing a high-powered laser beam
Assignee: United States Atomic Energy Commission
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Filing: 1973-01-03
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Granted: 1974-06-18
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Expires: 1993-01-03
Abstract
Abstract A method of providing a focal spot position independent of the input optical power of a laser beam. A negative lens is interposed such that focal spot motion caused by a changing refractive index in one lens element is canceled by an opposing motion in the negative lens element.
Inventors
- 👤 B Watt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:55
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/23; H01S3/2308; H01S3/2316; B; B23; B23K; B23K26/00; B23K26/02; G; G02; G02B; G02B13/00; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4204; G02B6/4206; G02B6/4296
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
A method of focusing a high-powered laser beam wherein a focal spot position is maintained independent of the input optical power which comprises interposing a negative lens between a focusing lens and its focal point, said negative lens providing an opposing focal spot motion sufficient to cancel focal spot motion caused by a changing angle of refraction in the focusing lens, the refractive index n of each lens being given by the expression n no + n Alpha p where no is the normal index of refraction, n Alpha the nonlinear coefficient and p the pOwer density of the beam in the lens.
Claim 2
Independent Claim
103 words
A method of focusing a high-powered laser beam wherein a focal spot position is maintained independent of the input optical power which comprises interposing a negative lens between a focusing lens and its focal point, said negative lens providing an opposing focal spot motion sufficient to cancel focal spot motion caused by a changing angle of refraction in the focusing lens, the refractive index n of each lens being given by the expression n no + n Alpha p where no is the normal index of refraction, n Alpha the nonlinear coefficient and p the pOwer density of the beam in the lens.
Claim 3
Dependent Claim
45 words
The method of claim 1 wherein said negative lens is composed of a glass having values of no and n sufficiently different from those of said focusing lens that the requisite opposing focal spot motion is produced for the particular spaced relationship between said lenses.
Claim 4
Dependent Claim
58 words
The method of claim 1 wherein said focusing lens and said negative lens are composed of the same optical glass and said negative lens is located in a region of said beam wherein the optical power density is sufficiently different from that of the beam entering said focusing lens that the requisite opposing focal spot motion is produced.
Claim 5
Dependent Claim
132 words
A lens system for use in focusing a high-powered laser beam wherein a focal spot position is maintained independent of the input optical power which comprises (a) a focusing lens, (b) a negative lens interposed between said focusing lens and its focal point, said negative lens being in spaced relationship to said focusing lens whereby it provides an opposing focal spot motion sufficient to cancel focal spot motion caused by a changing angle of refraction in said focusing lens, and (c) means for holding said lenses in said spaced relationship, the refractive index n of each lens being given by the expression n no + n Alpha p where no is the normal index of refraction, n Alpha the nonlinear coefficient and p the power density of the beam in the lens.
Claim 6
Dependent Claim
132 words
A lens system for use in focusing a high-powered laser beam wherein a focal spot position is maintained independent of the input optical power which comprises (a) a focusing lens, (b) a negative lens interposed between said focusing lens and its focal point, said negative lens being in spaced relationship to said focusing lens whereby it provides an opposing focal spot motion sufficient to cancel focal spot motion caused by a changing angle of refraction in said focusing lens, and (c) means for holding said lenses in said spaced relationship, the refractive index n of each lens being given by the expression n no + n Alpha p where no is the normal index of refraction, n Alpha the nonlinear coefficient and p the power density of the beam in the lens.
Claim 7
Dependent Claim
45 words
The lens system of claim 4 wherein said negative lens is composed of a glass having values of no and n sufficiently different from those of said focusing lens that the requisite opposing focal spot motion is produced for the spaced relationship between said lenses.
Claim 8
Dependent Claim
54 words
The lens system of claim 4 wherein said lenses are composed of the same optical glass, and the spaced relationship between said lenses is determined by the difference in optical power densities of the region of the beam in which said lenses are located, said difference being sufficient to produce canceling focal spot motion.
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) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |