US4436363A
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Broadband antireflection coating for infrared transmissive materials
Assignee: Westinghouse Electric Corp
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Filing: 1982-08-06
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Granted: 1984-03-13
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Expires: 2002-08-06
Abstract
Abstract A broadband antireflection multilayer coating for infrared transmissive materials comprises a first thin film layer selected from the group consisting of zinc-selenide and zinc-sulfide, a second thin film layer selected from the group consisting of lead-fluoride and aluminum oxide and a third thin film layer selected from the group consisting of magnesium-fluoride, barium-fluoride and calcium-fluoride. This antireflection coating is particularly useful with acousto-optic tunable filter systems, wire grid polarizers and infrared frequency doublers.
Inventors
- 👤 Kenneth B. Steinbruegge
- 👤 Johanna S. Schruben
- 👤 Lyle H. Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:54
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/285
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
96 words
A broadband antireflection coating for use on infrared transmissive materials comprising: a first thin layer, of a compound selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on the transmissive material; a second thin layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer; and a third thin layer of a compound, selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 2
Dependent Claim
96 words
A broadband antireflection coating for use on infrared transmissive materials comprising: a first thin layer, of a compound selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on the transmissive material; a second thin layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer; and a third thin layer of a compound, selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 3
Dependent Claim
37 words
The broadband antireflection coating of claim 1 wherein the first thin film layer is zinc-selenide (ZnSe): the second thin film layer is lead-fluoride (PbF 2 ); and the third thin film layer is calcium-fluoride (CaF 2 ).
Claim 4
Dependent Claim
42 words
The broadband antireflection coating of claim 2 wherein the first thin film layer is approximately 0.230 μm in thickness; the second thin film layer is approximately 0.365 μm in thickness; and the third thin film layer is approximately 0.396 μm in thickness.
Claim 5
Dependent Claim
37 words
The broadband antireflection coating of claim 1 wherein the first thin film layer is zinc-selenide (ZnSe); the second thin film layer is lead-fluoride (PbF 2 ); and the third thin film layer is magnesium-fluoride (MgF 2 ).
Claim 6
Dependent Claim
23 words
The broadband antireflection coating of claim 1 wherein the infrared trasmissive material is a crystal with the formula Tl 3 AsSe 3 .
Claim 7
Dependent Claim
135 words
An infrared transmissive device comprising a rhombohedial crystal having the formula Tl 3 AsSe 3 and including at least two polished opposing faces, in combination with a multilayer thin film antireflection coating disposed on at least the aforesaid two opposing faces, said multilayer thin film coating consisting of a first thin film layer, of a compound selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on said faces; a second thin film layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer; and a third thin film layer, of a compound selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 8
Dependent Claim
135 words
An infrared transmissive device comprising a rhombohedial crystal having the formula Tl 3 AsSe 3 and including at least two polished opposing faces, in combination with a multilayer thin film antireflection coating disposed on at least the aforesaid two opposing faces, said multilayer thin film coating consisting of a first thin film layer, of a compound selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on said faces; a second thin film layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer; and a third thin film layer, of a compound selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 9
Dependent Claim
42 words
The infrared transmissive device according to claim 6 wherein the antireflection coating comprises a first thin film layer of zinc-selenide (ZnSe), a second thin film layer of lead-fluoride (PbF 2 ), and a third thin film layer of magnesium-fluoride (MgF 2 ).
Claim 10
Dependent Claim
42 words
The infrared transmissive device according to claim 6 wherein the antireflection coating comprises a first thin film layer of zinc-selenide (ZnSe), a second thin film layer of lead-fluoride (PbF 2 ) and a third thin film layer of calcium-fluoride (CaF 2 ).
Claim 11
Dependent Claim
50 words
The infrared transmissive device according to claim 8 wherein the first thin film layer of the antireflection coating has a thickness of approximately 0.380 μm, the second thin film layer has a thickness of approximately 0.735 μm; and the third thin film layer has a thickness of approximately 0.640 μm.
Claim 12
Dependent Claim
110 words
In combination with a wire grid polarizer having an infrared transmitting substrate, a multilayer thin film antireflection coating disposed on said substrate, said antireflection coating comprising a first thin film layer of a compound, selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on said substrate, a second thin film layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer, and a third thin film layer, selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 13
Dependent Claim
110 words
In combination with a wire grid polarizer having an infrared transmitting substrate, a multilayer thin film antireflection coating disposed on said substrate, said antireflection coating comprising a first thin film layer of a compound, selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on said substrate, a second thin film layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer, and a third thin film layer, selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 14
Dependent Claim
39 words
The multilayer thin film antireflection coating of claim 10 wherein the first thin film layer is zinc-selenide (ZnSe); the second thin film layer is lead-fluoride (PbF 2 ); and the third thin film layer is calcium-fluoride (CaF 2 ).
Claim 15
Dependent Claim
44 words
The multilayer thin film antireflection coating of claim 11 wherein the first thin film layer is approximately 0.380 μm in thickness; the second thin film layer is approximately 0.735 μm in thickness; and the third thin film layer is approximately 0.649 μm in thickness.
Claim 16
Dependent Claim
37 words
The broadband antireflection coating of claim 10 wherein the first thin film layer is zinc-selenide (ZnSe), the second thin film layer is lead-fluoride (PbF 2 ), and the third thin film layer is magnesium-fluoride (MgF 2 ).
Claim 17
Dependent Claim
137 words
In combination with a crystal device with two opposing faces configured as a frequency doubler, a multilayer thin film antireflection coating disposed on at least said two opposing faces in order to promote infrared transmission at wavelengths of approximately 5 μm and 10 μm, said multilayer antireflection coating comprising: a first thin film layer, of a compound selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on said faces; a second thin film layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer; and a third thin film layer, selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 18
Dependent Claim
137 words
In combination with a crystal device with two opposing faces configured as a frequency doubler, a multilayer thin film antireflection coating disposed on at least said two opposing faces in order to promote infrared transmission at wavelengths of approximately 5 μm and 10 μm, said multilayer antireflection coating comprising: a first thin film layer, of a compound selected from the group consisting of zinc-selenide (ZnSe) and zinc-sulfide (ZnS), disposed on said faces; a second thin film layer, of a compound selected from the group consisting of lead-fluoride (PbF 2 ) and aluminum oxide (Al 2 O 3 ), disposed on said first layer; and a third thin film layer, selected from the group consisting of magnesium-fluoride (MgF 2 ), barium-fluoride (MgF 2 ), barium-fluoride (BaF 2 ) and calcium-fluoride (CaF 2 ), disposed on said second layer.
Claim 19
Dependent Claim
39 words
The multilayer thin film antireflection coating of claim 14 wherein the first thin film layer is zinc-selenide (ZnSe); the second thin film layer is lead-fluoride (PbF 2 ); and the third thin film layer is calcium-fluoride (CaF 2 ).
Claim 20
Dependent Claim
44 words
The multilayer thin film antireflection coating of claim 15 wherein the first thin film layer is approximately 0.601 μm in thickness; the second thin film layer is approximately 0.918 μm in thickness; and the third thin film layer is approximately 0.707 μm in thickness.
References Cited (Backward Citations)
US2858240A
Cited
US3792287A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |