US4395090A
Expired / Lapsed
US
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Optical cut-off filter
Assignee: Siemens AG
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Filing: 1981-03-05
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Granted: 1983-07-26
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Expires: 2001-03-05
Abstract
Abstract An optical cut-off filter characterized by a multi-layer system comprising of a sequence of dielectric layers which are bordered on each side by a transparent medium having an equal or same index of refraction with the index of refraction of each of the dielectric layers being selected so that for a preselected radiation angle of incidence, the band paths of the filter have an envelope of reflected secondary maximum for a component vibrating perpendicular to the radiation plane of incidence and the envelope for a component vibrating parallel to the radiation of planar incidence of the electrical field vector of incident radiation, and both envelopes exhibit zero locations which have a different wavelength due to the selection of the index of refraction of the dielectric layers forming the filter.
Inventors
- 👤 Hans F. Mahlein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:22
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/281; G02B5/282
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
176 words
In an optical cut-off filter in the form of a multilayer system comprising a sequence of dielectric layers A and B interposed between a transparent bordering medium having an index of refraction n 0 , and with an index of refraction n A for each of the layers A and an index of refraction n B for each of said layers B selected so that, for a preselected radiation angle of incidence θ, the pass band of the filter has an envelope E s of the reflecting secondary maxima for the s-component vibrating perpendicular to the radiation plane of incidence and an envelope E p for the p-component vibrating parallel to the radiation plane of incidence of the electrical field vector of the incident radiation, and wherein each envelope has a zero location, the improvement comprising having the indices of refraction n A and n B of the dielectric layers A and B of the filter selected so that the zero locations of the two envelopes E s and E p lie at somewhat different wavelengths.
Claim 2
Dependent Claim
176 words
In an optical cut-off filter in the form of a multilayer system comprising a sequence of dielectric layers A and B interposed between a transparent bordering medium having an index of refraction n 0 , and with an index of refraction n A for each of the layers A and an index of refraction n B for each of said layers B selected so that, for a preselected radiation angle of incidence θ, the pass band of the filter has an envelope E s of the reflecting secondary maxima for the s-component vibrating perpendicular to the radiation plane of incidence and an envelope E p for the p-component vibrating parallel to the radiation plane of incidence of the electrical field vector of the incident radiation, and wherein each envelope has a zero location, the improvement comprising having the indices of refraction n A and n B of the dielectric layers A and B of the filter selected so that the zero locations of the two envelopes E s and E p lie at somewhat different wavelengths.
Claim 3
Dependent Claim
73 words
The optical cut-off filter according to claim 1, wherein the multi-system layer exhibits a layer structure ##EQU32## wherein ##EQU33## signifies k multiple sequences of symmetrical layers A and B layers of a fundamental period of ##EQU34## wherein the layer A/2 has the index of refraction n A and the layer B has the index of refraction n B and S signifies the bordering transparent medium having an index of refraction n 0 .
Claim 4
Dependent Claim
20 words
The optical cut-off filter according to claim 2, wherein n 0 =1.46, n A =2.35, n B =1.70 and k=13.
Claim 5
Dependent Claim
20 words
The optical cut-off filter according to claim 2, wherein n 0 =1.46, n A =2.35, n B =1.90 and k=18.
Claim 6
Dependent Claim
20 words
The optical cut-off filter according to claim 2, wherein n 0 =1.46, n A =2.35, n B =1.65 and k=13.
Claim 7
Dependent Claim
14 words
The optical cut-off filter according to claim 2, wherein n A >n B .
Claim 8
Dependent Claim
32 words
The optical cut-off filter according to claim 2, wherein the indices of refraction n A and n B are greater than the index of refraction n 0 of the transparent medium S.
Claim 9
Dependent Claim
14 words
The optical cut-off filter according to claim 7, wherein n A >n B .
Claim 10
Dependent Claim
36 words
The optical cut-off filter according to claim 7, wherein the radiation angle of incidence θ is at θ=45° and the indices of refraction n B , n A and n 0 satisfy the following relationship: ##EQU35##
Claim 11
Dependent Claim
14 words
The optical cut-off filter according to claim 9, wherein n A >n B .
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) | 1986-07-25 | 1987-01-24 | 1987-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-25 | 1991-01-24 | 1991-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-25 | 1995-01-24 | 1995-07-26 | $7700.00 | Window Closed / Lapsed |