US4769290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High efficiency reflectors and methods for making them
Assignee: Raytheon Co
•
Filing: 1987-01-06
•
Granted: 1988-09-06
•
Expires: 2007-01-06
Abstract
Abstract An article of manufacture includes a substrate carrying at least two coating layers, one layer being of approximately quarter wave optical thickness, the other layer of approximately two quarter wave optical thickness, with the layers alternating between a material such as a dielectric having a first index of refraction and a second material such as a dielectric having a second index of refraction lower than the first index of refraction. These layers form a filtering system which removes narrow bands of light such as laser wavelengths by efficient reflection while permitting the remainder of the light spectrum to pass through the article. The coating layers have optical thicknesses and indices of refraction appropriate to reflect more than 99% of incident light at one or more predetermined wavelengths of light in the range of about 300 to about 1,200 nanometers and to transmit a substantial amount of all other incident light in the range. These articles are made by an electron beam evaporation technique under vacuum and under controlled conditions of temperature, partial pressure of oxygen, and deposition rates.
Inventors
- 👤 Herbert L. Hettich
- 👤 Samuel F. Pellicori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:28
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/285; G02B5/286; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/26; Y10T428/261; Y10T428/31504; Y10T428/31507
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
124 words
An article of manufacture comprising a substrate selected from the group consisting of glass and polymeric materials carrying at least two coating layers, one layer being of approximately quarter wave optical thickness, and the other being of approximately two quarter wave optical thickness, said layers alternating between a material having a first index of refraction and a material having a second index of refraction lower than said first index of refraction, said coating layers having optical thicknesses and indices of refraction suffficient to reflect more than 99% of incident light at substantially all wavelengths within one or more predetermined bandwidths of wavelengths, said bandwidths having a width of up to about 50 nanometers, and to transmit a substantial amount of all other incident light.
Claim 2
Dependent Claim
124 words
An article of manufacture comprising a substrate selected from the group consisting of glass and polymeric materials carrying at least two coating layers, one layer being of approximately quarter wave optical thickness, and the other being of approximately two quarter wave optical thickness, said layers alternating between a material having a first index of refraction and a material having a second index of refraction lower than said first index of refraction, said coating layers having optical thicknesses and indices of refraction suffficient to reflect more than 99% of incident light at substantially all wavelengths within one or more predetermined bandwidths of wavelengths, said bandwidths having a width of up to about 50 nanometers, and to transmit a substantial amount of all other incident light.
Claim 3
Dependent Claim
23 words
The article of claim 1 futher comprising in the range of about 10 to about 20 repeating groups of said alternating coating layers.
Claim 4
Dependent Claim
37 words
The article of claim 2 wherein said first index of refraction is in the range of about 1.9 to about 2.3, and said second index of refraction is in the range of about 1.43 to about 1.5.
Claim 5
Dependent Claim
35 words
The article of claim 3 wherein said first layer is selected from the group consisting of tantulum oxide, titanium oxide and hafnium oxide, and said second layer is silicon dioxide or Schott evaporation glass 8329.
Claim 6
Dependent Claim
29 words
The article of claim 4 wherein said article reflects more than 99% of incident light in narrow bandwidths of light wavelengths around 1,064 nanometers, 532 nanometers and 358 nanometers.
Claim 7
Dependent Claim
41 words
The article of claim 5 wherein said narrow bandwidths are of sufficient breadth to reflect said more than 99% of incident light where the angle of incidence of said incident light is in the range of about 0° to about 25°.
Claim 8
Dependent Claim
62 words
The article of claim 1 wherein each of said layers is a quarter wave optical thickness at a wavelength λ 0 , and wherein said article has a reflection band of said more than 99% of incident light of at least one wavelength equal to 3 λ 0 /4 m, wherein m is an integer 1, 2, 4, 5, 7 or 8.
Claim 9
Dependent Claim
109 words
The article of claim 1 wherein said substrate is polycarbonate or glass; said first layer is selected from the group consisting of tantalum oxide, titanium oxide, and hafnium oxide, and has an index of refraction in the range of about 1.9 to about 2.3, and said second layer is silicon dioxide with an index of refraction in the range of about 1.43 to about 1.5, and wherein said article reflects more than 99.99% of incident light in narrow bandwidths of wavelengths of incident light around 1,064 nanometers and 532 nanometers where the angle of incidence of the incident light is in the range of about 0° to about 25°.
Claim 10
Dependent Claim
22 words
The article of claim 1 made by electron beam evaporation, under vacuum, of said materials of first and second indices of refraction.
Claim 11
Dependent Claim
96 words
The article of claim 9 wherein said vacuum is below 2×10 -4 Torr; layer thicknesses are monitored and controlled with an optical reflectance monitor; deposition rate is measured with a quartz crystal; a partial pressure of oxygen is maintained within the vacuum zone, said partial pressure being not greater than about 2×10 -4 Torr ±20%; the deposition rate of said materials is controlled to a value within the range of about 5 to about 10 angstroms per second; and the temperature of said substrate is maintained below a temperature at which said substrate would be damaged.
Claim 12
Dependent Claim
156 words
An article of manufacture comprising a substrate selected from the group consisting of glass and polymeric materials carrying at least two coating layers, with one layer being of approximately quarter wave optical thickness, and the other layer of approximately two quarter wave optical thickness, said layers alternating between a material having a first index of refraction and a material having a second index of refraction lower than said first index of refraction, said coating layers having optical thicknesses and indices of refraction sufficient to reflect more than 99% of incident light at substantially all wavelengths within one or more predetermined bandwidths of wavelengths, said bandwidths having a width of up to about 50 nanometers, said bandwidths being of sufficient breadth to reflect more than 99% of incident light, where the angle of said incident light is in the range of about 0° to about 25° and to transmit a substantial amount of all other incident light.
Claim 13
Dependent Claim
156 words
An article of manufacture comprising a substrate selected from the group consisting of glass and polymeric materials carrying at least two coating layers, with one layer being of approximately quarter wave optical thickness, and the other layer of approximately two quarter wave optical thickness, said layers alternating between a material having a first index of refraction and a material having a second index of refraction lower than said first index of refraction, said coating layers having optical thicknesses and indices of refraction sufficient to reflect more than 99% of incident light at substantially all wavelengths within one or more predetermined bandwidths of wavelengths, said bandwidths having a width of up to about 50 nanometers, said bandwidths being of sufficient breadth to reflect more than 99% of incident light, where the angle of said incident light is in the range of about 0° to about 25° and to transmit a substantial amount of all other incident light.
Claim 14
Dependent Claim
37 words
The article of claim 11 wherein said first index of refraction is in the range of about 1.43 to about 1.5, and said second index of refraction is in the range of about 1.9 to about 2.3.
Claim 15
Dependent Claim
30 words
The article of claim 11 wherein said first layer is selected from the group consisting of tantalum oxide, titanium oxide and hafnium oxide, and said second layer is silicon dioxide.
Claim 16
Dependent Claim
29 words
The article of claim 11 wherein said article reflects more than 99% of incident light in narrow bandwidths of light wavelengths around 1,064 nanometers, 532 nanometers and 358 nanometers.
Claim 17
Dependent Claim
131 words
An article of manufacture comprising a substrate selected from the group consisting of glass and polymeric materials carrying at least about 10 repeating groups with each group comprising at least two coating layers being of approximately two quarter waves optical thickness, and the other layer being of approximately one quarter wave optical thickness, said layers alternating between a material having a first index of refraction and a second index of refraction, lower than said first index of refraction, said coating layers having optical thicknesses and indices of refraction sufficient to reflect more than 99% of incident light at substantially all wavelengths within one or more predetermined bandwidths of wavelengths, said bandwidths, having a width of up to about 50 nanometers, and to transmit a substantial amount of all other incident light.
Claim 18
Dependent Claim
131 words
An article of manufacture comprising a substrate selected from the group consisting of glass and polymeric materials carrying at least about 10 repeating groups with each group comprising at least two coating layers being of approximately two quarter waves optical thickness, and the other layer being of approximately one quarter wave optical thickness, said layers alternating between a material having a first index of refraction and a second index of refraction, lower than said first index of refraction, said coating layers having optical thicknesses and indices of refraction sufficient to reflect more than 99% of incident light at substantially all wavelengths within one or more predetermined bandwidths of wavelengths, said bandwidths, having a width of up to about 50 nanometers, and to transmit a substantial amount of all other incident light.
Claim 19
Dependent Claim
37 words
The article of claim 15 wherein said first index of refraction is in the range of about 1.9 to about 2.3 and said second index of refraction is in the range of about 1.43 to about 1.5.
Claim 20
Dependent Claim
30 words
The article of claim 15 wherein said first layer is selected from the group consisting of tantalum oxide, titanium oxide and hafnium oxide, and said second layer is silicon dioxide.
Claim 21
Dependent Claim
29 words
The article of claim 15 wherein said article reflects more than 99% of incident light in narrow bandwidths of light wavelengths around 1,064 nanometers, 532 nanometers and 358 nanometers.
References Cited (Backward Citations)
US2412496A
Cited
US2552185A
Cited
US3410626A
Cited
US3504959A
Cited
US4196246A
Cited
GB2070275A
Cited
JPS6064843A
Cited
US4659178A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |