US4099854A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical notch filter utilizing electric dipole resonance absorption
Assignee: United States Department of the Navy
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Filing: 1976-10-12
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Granted: 1978-07-11
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Expires: 1996-10-12
Abstract
Abstract An optical notch filter having a suspension of small absorbing particles which blocks a narrow band of frequencies. The small absorbent particles are suspended as a colloidal system which can have either a solid, liquid or gas as host material. The absorbing particles can be incorporated in a solid matrix as a transmission filter or used on the surface of a mirror as a reflection filter. The filter can be tuned by an externally applied electric field or by applying hydrostatic pressure.
Inventors
- 👤 Donald L. Decker
- 👤 William M. Tolles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:17
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/17; G02F1/172; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/24
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
80 words
An optical notch filter comprising: a suspending material wherein said suspending material comprises a material selected from the group consisting of air, KBr, NaF, CaF 2 , BaF 2 , LiF, KCl, NaCl, KRS-5 and ZnSe; and a plurality of absorbing particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength.
Claim 2
Dependent Claim
80 words
An optical notch filter comprising: a suspending material wherein said suspending material comprises a material selected from the group consisting of air, KBr, NaF, CaF 2 , BaF 2 , LiF, KCl, NaCl, KRS-5 and ZnSe; and a plurality of absorbing particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength.
Claim 3
Dependent Claim
33 words
An optical notch filter as recited in claim 1 further comprising a means for reflecting said incident radiation situated such that said colloidal system is between said reflecting means and said incident radiation.
Claim 4
Dependent Claim
87 words
An optical notch filter comprising: a suspending material; and a plurality of absorbing particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength. wherein said absorbing particles comprise a material selected from the group consisting of MgO, BeO, αAl 2 O 3 , BN, Ag 1-x Cd x alloy system, Ag 1-x Zn x alloy system and Ag.
Claim 5
Dependent Claim
87 words
An optical notch filter comprising: a suspending material; and a plurality of absorbing particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength. wherein said absorbing particles comprise a material selected from the group consisting of MgO, BeO, αAl 2 O 3 , BN, Ag 1-x Cd x alloy system, Ag 1-x Zn x alloy system and Ag.
Claim 6
Dependent Claim
36 words
An optical notch filter as recited in claim 3 wherein said Ag 1-x Cd x and Ag 1-x Zn x alloy systems comprise Ag alloyed with Cd and Zn, respectively, to at least 30% atomic concentration.
Claim 7
Dependent Claim
33 words
An optical notch filter as recited in claim 3 further comprising a means for reflecting said incident radiation, situated such that said colloidal system is between said reflecting means and said incident radiation.
Claim 8
Dependent Claim
21 words
An optical notch filter as recited in claim 3 wherein said suspending material comprises a material transparent to said incident radiation.
Claim 9
Dependent Claim
16 words
An optical notch filter as recited in claim 3 wherein said suspending material comprises a solid.
Claim 10
Dependent Claim
16 words
An optical notch filter as recited in claim 3 wherein said suspending material comprises a fluid.
Claim 11
Dependent Claim
15 words
An optical notch filter as recited in claim 8 wherein said fluid is a gas.
Claim 12
Dependent Claim
15 words
An optical notch filter as recited in claim 8 wherein said fluid is a liquid.
Claim 13
Dependent Claim
17 words
An optical notch filter as recited in claim 10 wherein said liquid is a miscible lyophilic liquid.
Claim 14
Dependent Claim
57 words
An optical notch filter comprising a suspending material; a plurality of absoring particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength; and means for tuning said filter.
Claim 15
Dependent Claim
57 words
An optical notch filter comprising a suspending material; a plurality of absoring particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength; and means for tuning said filter.
Claim 16
Dependent Claim
30 words
An optical notch filter as recited in claim 12 wherein said tuning means comprises a means for applying an external electric field to said filter to vary said dielectric constant.
Claim 17
Dependent Claim
34 words
An optical notch filter as recited in claim 13 wherein said absorbing particles are non-spherical in shape so that the resonant absorption condition is dependent upon the geometric shape and orientation of said particles.
Claim 18
Dependent Claim
23 words
An optical notch filter as recited in claim 13 wherein said tuning means comprises a means for applying hydrostatic pressure to said filter.
Claim 19
Dependent Claim
27 words
An optical notch filter as set forth in claim 12 wherein said filter's absorption wavelength is shifted by predetermined changes in the composition of said suspending material.
Claim 20
Dependent Claim
27 words
An optical notch filter as set forth in claim 12 wherein said filter's absorption wavelength is shifted by predetermined changes in the composition of said absorbing particles.
Claim 21
Independent Claim
77 words
A method for producing an optical notch filter comprising the steps of: mulling a plurality of absorbing particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength, together with a finely ground powder of a suspending material without changing the character of said absorbing particles; and pressing said mulled powder mixture in a vacuum to form a solid matrix.
Claim 22
Independent Claim
77 words
A method for producing an optical notch filter comprising the steps of: mulling a plurality of absorbing particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength, together with a finely ground powder of a suspending material without changing the character of said absorbing particles; and pressing said mulled powder mixture in a vacuum to form a solid matrix.
Claim 23
Dependent Claim
37 words
A method for producing an optical notch filter as recited in claim 18 further comprising the step of heating said mulled powder mixture to a temperature of about 150° to 350° C while pressing said powder mixture.
Claim 24
Dependent Claim
29 words
A method for producing an optical notch filter as recited in claim 19 wherein the step of pressing comprises pressing with a pressure of 100,000 lb/in 2 or less.
Claim 25
Dependent Claim
106 words
An optical notch filter comprising; a suspending material selected from the group consisting of air, KBr, NaF, CaF 2 , BaF 2 , LiF, KCl, NaCl, KRS-5 and ZnSe; and a plurality of absorbing particles within said suspending material to form a colloidal system said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength, wherein said absorbing particles are selected from the group consisting of MgO, BeO, αAl 2 O 3 , BN, Ag 1-x Cd x alloy system, Ag 1-x Zn x alloy system and Ag.
Claim 26
Dependent Claim
106 words
An optical notch filter comprising; a suspending material selected from the group consisting of air, KBr, NaF, CaF 2 , BaF 2 , LiF, KCl, NaCl, KRS-5 and ZnSe; and a plurality of absorbing particles within said suspending material to form a colloidal system said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength, wherein said absorbing particles are selected from the group consisting of MgO, BeO, αAl 2 O 3 , BN, Ag 1-x Cd x alloy system, Ag 1-x Zn x alloy system and Ag.
Claim 27
Dependent Claim
32 words
An optical notch filter as recited in claim 21 further comprising a means for reflecting said incident radiation such that said colloidal system is between said reflecting means and said incident radiation.
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) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |