Three variable optimization system for thin film coating design

• US 5,812,405 A
• Filed: 05/23/1995
• Issued: 09/22/1998
• Est. Priority Date: 05/23/1995
• Status: Expired due to Fees

• Current Assignee: Tru Vue Inc. (Apogee Enterprises Incorporated)
• Original Assignee: Viratec Thin Films, Inc. (Apogee Enterprises Incorporated)
• Inventors: Meredith, William A. Jr.
• Primary Examiner(s): Gordon, Paul P.
• Assistant Examiner(s): PATEL, RAMESH B
• Application Number:
  US08/448,233
• Time in Patent Office: 1,218 Days
• Field of Search: 364/473.03, 364/473.01, 364/473.02, 364/479.09, 364/473.05, 364/474.25, 364/468.03, 364/468.02, 428/34, 428/426, 428/428, 428/432, 359/586, 359/580, 359/588, 359/589, 350/166, 350/164, 257/436, 257/437, 427/162, 427/163.1, 205/169, 205/170, 205/143
• US Class Current: 700/157
• CPC Class Codes: G02B 27/0012 Optical design, e.g. procedures, algorithms, optimisation routines
• CPC Class Codes: G02B 5/285 comprising deposited thin solid films G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361

Abstract

A method and system for designing and manufacturing a high-performance, optimized optical interference coatings that have a minimal number of layers. Index of refraction, absorption coefficient, and thickness values are selected for each of the layers in the design so as to cause the reflectance of a coated object to be zero for a given wavelength. Materials that with the selected properties are manufactured by mixing two or more preexisting available materials.

Claims

1. A method of operating a computer to design an anti-reflective coating that is optimized for a given wavelength, wherein the anti-reflective coating comprises one or more layers, the method comprising the acts of:

accepting as input a layer count value, wherein the layer count value is the number of layers that will make up the anti-reflective coating;

finding, for each of the layers, three optimized values that will cause the reflectance properties of a substrate coated with the anti-reflective coating to be non-reflective for the given wavelength, wherein the three optimized values for each layer comprise an optimized absorption coefficient, an optimized index of refraction, and an optimized thickness, and wherein the three optimized values for at least one layer are all greater than zero; and

determining, for each of the layers, what proportion of two or more available thin film materials will result in a mixture that will match the three optimized values.

2. The method of claim 1, further comprising the act of:

applying the mixture of the available materials to the substrate in the determined proportions.

3. The method of claim 1, wherein the act of determining, for each of the layers, what proportion of two or more available thin film materials will result in a mixture that will match the three optimized values includes the act of:

selecting, for each of the layers, two or more available thin film materials.

4. The method of claim 3, further comprising the acts of:

mixing, for each of the layers, the selected available thin film materials; and

applying the mixture to the substrate.

5. The method of claim 1, wherein the two or more available thin film materials are combined in a mixture where the two or more available thin film materials are not bonded by a molecular bond.

6. A system for designing an anti-reflective coating that is optimized for a given wavelength, wherein the anti-reflective coating comprises one or more layers, the system comprising:

(a) a computer; and

(b) a data storage medium that is accessible by the computer, wherein the data storage medium has a program stored on it that is capable of being executed by the computer, and that is configured to cause the computer to;

accept as input a layer count value, wherein the layer count value is the number of layers that will make up the anti-reflective coating,

find, for each of the layers, three optimized values that will cause the reflectance properties of a substrate coated with the anti-reflective coating to be non-reflective for the given wavelength, wherein the three optimized values for each layer comprise an optimized absorption coefficient, an optimized index of refraction, and an optimized thickness, and wherein the three optimized values for at least one layer are all greater than zero, and

determine, for each of the layers, what proportion of two or more available thin film materials will result in a mixture that will match the three optimized values.

7. The system of claim 6, further comprising:

(c) a coating mechanism that is capable of coating the substrate, and which is controlled by the computer;

wherein the computer program is further configured to cause the computer to control the coating mechanism so that the mixture of the available materials is applied to the substrate in the determined proportions.

8. The system of claim 6, wherein the program is further configured to cause the computer to:

select, for each of the layers, two or more available thin film materials.

9. The system of claim 8, further comprising:

(c) mixing means for applying the selected available thin film materials; and

(d) coating means for applying the mixture to the substrate.

10. The system of claim 9, wherein the selected two or more available thin film materials are combined in a mixture where the two or more selected available thin film materials are not bonded by a molecular bond.

11. A system for designing an anti-reflective coating that is optimized for a given wavelength, wherein the anti-reflective coating comprises one or more layers, the system comprising:

means for accepting as input a layer count value, wherein the layer count value is the number of layers that will make up the anti-reflective coating;

means for finding, for each of the layers, three optimized values that will cause the reflectance of a substrate coated with the anti-reflective coating to be substantially zero for the given wavelength, wherein the three optimized values for each layer comprise an optimized absorption coefficient, an optimized index of refraction, and an optimized thickness, and wherein the three optimized values for at least one layer are all greater than zero; and

means for determining, for each of the layers, what proportion of two or more available thin film materials will result in a mixture that will match the three optimized values.

12. The system of claim 11, further comprising:

means for applying the mixture of the available materials to the substrate in the determined proportions.

13. A method of operating a computer to design an anti-reflective coating, wherein the anti-reflective coating comprises one or more layers, the method comprising the acts of:

accepting as input a layer count value, wherein the layer count value is the number of layers that will make up the anti-reflective coating;

finding, for each of the layers, three optimized values that will cause the reflectance properties of a substrate coated with the anti-reflective coating to be non-reflective, wherein the three optimized values for each layer comprise an optimized absorption coefficient, an optimized index of refraction, and an optimized thickness, and wherein the three optimized values for at least one layer are all greater than zero; and

determining, for each of the layers, what proportion of two or more available thin film materials will result in a combination that will match the three optimized values.