US4890075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical radiation limiter
Assignee: SRI International Inc
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Filing: 1986-07-31
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Granted: 1989-12-26
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Expires: 2006-07-31
Abstract
Abstract A nonlinear optical fluid with radiation-absorbing small particles uniformly suspended in the fluid. For radiation below a threshold value, radiation passes through with slight attenuation. Above the threshold, only a limited level of radiation is passed, the limit being below the damage level of a sensitive optical detector.
Inventors
- 👤 Juergen L. W. Pohlmann
- 👤 Richard C. Honey
- 👤 John L. Guagliardo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:01
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/3523
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
112 words
An optical energy and/or power limiter for protecting a sensitive optical detector from high-energy or high-power optical radiation and including: a limiting cell containing a nonlinear optical fluid essentially transparent to optical radiation below a first energy or power threshold, and only partially transparent to said radiation above said threshold, and further containing optical radiation absorbers in the form of finely divided particles essentially uniformly distributed throughout said fluid and, means for focusing said radiation into said cell, whereby said cell is interposed between said means and said detector is only partially transparent to radiation above a second energy or power threshold, and wherein said second threshold is lower than first threshold.
Claim 2
Dependent Claim
112 words
An optical energy and/or power limiter for protecting a sensitive optical detector from high-energy or high-power optical radiation and including: a limiting cell containing a nonlinear optical fluid essentially transparent to optical radiation below a first energy or power threshold, and only partially transparent to said radiation above said threshold, and further containing optical radiation absorbers in the form of finely divided particles essentially uniformly distributed throughout said fluid and, means for focusing said radiation into said cell, whereby said cell is interposed between said means and said detector is only partially transparent to radiation above a second energy or power threshold, and wherein said second threshold is lower than first threshold.
Claim 3
Dependent Claim
23 words
The device as set forth in claim 1 wherein said particles are carbon with dimensions comparable to or less than the radiation wavelengths.
Claim 4
Dependent Claim
25 words
The device as set for the in claim 1 wherein said particles are metallic blacks with dimensions comparable to or less than the radiation wavelengths.
References Cited (Backward Citations)
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US3614211A
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US3458249A
Cited
US4407565A
Cited
US4536061A
Cited
US4632517A
Cited
US4622174A
Cited
US4622174B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |