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US4846561A
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Monolithic optical power limiter based on two-photon absorption
Assignee: CENTER FOR RESEARCH IN ELECTRO-OPTICS AND LASERS (CREOL)
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Filing: 1988-06-21
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Granted: 1989-07-11
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Expires: 2008-06-21
Abstract
Abstract Collimated incident optical radiation which might contain high-intensity or high-power radiation is focused into the body of a limiter by a first lens formed at one end of the limiter. The body is a cylinder of revolution with an axis along the optical axis between radiation and a sensitive detector. Radiation of normal intensity or power freely passes through the body and is recollimated by a second lens formed at the other end of the limiter from the first lens. The body is made of material which is subject to two-photon absorption such that high-intensity or high-power radiation undergoes absorption and is consequently self-defocused such that it is diverted from the optical path. For visible light, the material may be ZeSe or ZnS; for ultraviolet, copper chloride; for infrared, HgCgTe.
Inventors
- 👤 Marion J. Soileau, Jr.
- 👤 Eric W. Van Stryland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:21
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/23; G02F; G02F1/00; G02F1/35; G02F1/3526
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
156 words
A unitary device for protecting a sensitive optical detector from high-power or high-intensity radiation of a particular wavelength or band of wavelengths, wherein said device is in the form of a cooled cylindrical body with a longitudinal axis and with positive lenses on either end of said body along said axis, whereby said body is made of a material subject to two-photon absorption of incident radiation and is chosen from the group consisting of: ZnSe, ZnS, copper chloride, and Hg 1-x Cd x Te, and whereby said body is placed with its axis colinear with the optical axis is an optical system such that incident radiation below a threshold intensity or power level mostly transmits through said body but incident radiation above said level undergoes two-photon absorption with consequent self-defocusing in said body whereby the self-defocussed radiation is diverted from said detector, and the radiation which transmits through said body is limited to said threshold level.
Claim 2
Dependent Claim
156 words
A unitary device for protecting a sensitive optical detector from high-power or high-intensity radiation of a particular wavelength or band of wavelengths, wherein said device is in the form of a cooled cylindrical body with a longitudinal axis and with positive lenses on either end of said body along said axis, whereby said body is made of a material subject to two-photon absorption of incident radiation and is chosen from the group consisting of: ZnSe, ZnS, copper chloride, and Hg 1-x Cd x Te, and whereby said body is placed with its axis colinear with the optical axis is an optical system such that incident radiation below a threshold intensity or power level mostly transmits through said body but incident radiation above said level undergoes two-photon absorption with consequent self-defocusing in said body whereby the self-defocussed radiation is diverted from said detector, and the radiation which transmits through said body is limited to said threshold level.
Claim 3
Dependent Claim
22 words
The device as set forth in claim 1 wherein the length of said body is twice the focal length of said lenses.
Claim 4
Dependent Claim
37 words
The device as set forth in claim 1 wherein x is determined from the following formula: Eg=-0.302+1.93x+5.35(10.sup.-4)T(1-2x)-0.810x.sup.2 +0.832x.sup.3 and wherein Eg is the energy gap corresponding to said particular wavelength and T is temperature in degrees Kelvin.
Claim 5
Dependent Claim
37 words
The device as set forth in claim 2 wherein x is determined from the following formula: Eg=-0.302+1.93x+5.35(10.sup.-4)T(1-2x)-0.810x.sup.2 +0.832x.sup.3 and wherein Eg is the energy gap corresponding to said particular wavelength and T is temperature in degrees Kelvin.
Claim 6
Dependent Claim
117 words
A unitary device for protecting a sensitive optical detector from high-power or high-intensity radiation of a particular wavelength or band of wavelengths, wherein the device is of a cooled material subject to two-photon absorption of incident radiation and wherein the material is a body of revolution with a length L along an optical axis between said radiation and said detector, and includes a first end formed as a lens for focusing collimated incident radiation as a spot into said body, and a second end formed as a lens for recollimating radiation which transmits through said body onto said detector, whereby high-power or high-intensity radiation of said particular wavelength or band of wavelengths is self-defocused by said material.
Claim 7
Dependent Claim
117 words
A unitary device for protecting a sensitive optical detector from high-power or high-intensity radiation of a particular wavelength or band of wavelengths, wherein the device is of a cooled material subject to two-photon absorption of incident radiation and wherein the material is a body of revolution with a length L along an optical axis between said radiation and said detector, and includes a first end formed as a lens for focusing collimated incident radiation as a spot into said body, and a second end formed as a lens for recollimating radiation which transmits through said body onto said detector, whereby high-power or high-intensity radiation of said particular wavelength or band of wavelengths is self-defocused by said material.
Claim 8
Dependent Claim
29 words
The device as set forth in claim 5 wherein said lenses have the same focal length and wherein L is equal to twice the focal length of each lens.
References Cited (Backward Citations)
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