OMNIDIRECTIONAL UV-IR REFLECTOR

• US 20110134515A1
• Filed: 01/26/2011
• Published: 06/09/2011
• Est. Priority Date: 08/12/2007
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Motor Corporation, Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Banerjee, Debasish, Zhang, Minjuan, Ishii, Masahiko
• Granted Patent: US 9,229,140 B2
• Time in Patent Office: Days
• US Class Current: 359/359
• CPC Class Codes: G02B 5/281 designed for the infrared light
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• CPC Class Codes: G02B 5/283 designed for the ultraviolet
• 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

The present invention provides an omnidirectional ultraviolet (UV)-infrared (IR) reflector. The omnidirectional UV-IR reflector includes a multilayer stack having at least three layers, the at least three layers having at least one first index of refraction material A1 and at least one second index of refraction layer B1. The at least one first index of refraction material layer and the at least one second index of refraction material layer can be alternately stacked on top of each other to provide the at least three layers. In addition, the at least one first index of refraction material layer and the at least one second index of refraction material layer each have a predefined thickness of d_A1 and d_B1, respectively, with the thickness d_A1 not being generally equal to the d_B1 thickness such that the multilayer stack has a non-periodic layered structure.

Claims

1. An omnidirectional UV-IR reflector comprising:

a multilayer stack having at least three layers, said at least three layers having at least one first index of refraction material layer H1 and at least two second index of refraction material layers L1 and L2, said at least one first index of refraction material layer and said at least two second index of refraction material layers alternately stacked on top of each other;

said at least three layers each having a predefined thicicness of d_H1, d_L1, d_L2 with said d_L1 thickness not generally equal to said d_L2 thickness such that said multilayer stack has a non-periodic layered structure; and

wherein said multilayer stack, at incident angles between 0 to 45 degrees, has a first omnidirectional reflection band for electromagnetic radiation having a wavelength of less than about 400 nanometers, a second omnidirectional reflection band for electromagnetic radiation having a wavelength of greater than about 800 nanometers, and an omnidirectional transparency band between said first omnidirectional reflection band and said second omnidirectional reflection band.

2. The omnidirectional UV-IR reflector of claim 1, wherein said multilayer stack, at incident angles between 0 to 45 degrees, has a transparency of at least 20% at a wavelength of about 850 nanometers.

3. The omnidirectional UV-IR reflector of claim 1, wherein said first omnidirectional reflection band and said second omnidirectional reflection band reflect at least 50% of said electromagnetic radiation having a wavelength of less than about 400 nanometers and at least 50% of said electromagnetic radiation having a wavelength of greater than about 800 nanometers, respectively.

4. The omnidirectional UV-IR reflector of claim 3, wherein said first omnidirectional reflection band and said second omnidirectional reflection band reflect at least 75% of said electromagnetic radiation having a wavelength of less than about 400 nanometers and at least 75% of said electromagnetic radiation having a wavelength of greater than about 800 nanometers, respectively.

5. The omnidirectional UV-IR reflector of claim 3, wherein said omnidirectional transparency band is greater than 80% transparent for electromagnetic radiation having a wavelength between about 400 to 800 nanometers.

6. The omnidirectional UV-IR reflector of claim 5, wherein said omnidirectional transparency band is greater than 90% transparent for electromagnetic radiation having a wavelength between about 400 to 800 nanometers.

7. The omnidirectional UV-IR reflector of claim 1, wherein said multilayer stack reflects greater than 50% of electromagnetic radiation having wavelengths between about 800 and 1400 nanometers.

8. The omnidirectional UV-IR reflector of claim 1, wherein said multilayer stack reflects greater than 75% of electromagnetic radiation having wavelengths between about 800 and 1400 nanometers.

9. The omnidirectional UV-IR reflector of claim 1, further comprising at least one third index of refraction material layer M1, said at least one first index of refraction material layer, said at least two second index of refraction layers and at least one third index of refraction material layer alternately stacked on top of each other such that said multilayer stack has at least four layers;

said at least four layers each having a predefined thickness of d_H1, d_L1, d_L2, d_M1 with said d_L1 thickness not generally equal to said d_L2 thickness such that said multilayer stack has a non-periodic layered structure.

10. The omnidirectional UV-IR reflector of claim 9, wherein said multilayer stack, at incident angles between 0 to 45 degrees, has a transparency of at least 20% at a wavelength of about 850 nanometers.

11. The omnidirectional UV-IR reflector of claim 9, wherein said first omnidirectional reflection band and said second omnidirectional reflection band reflect at least 50% of said electromagnetic radiation having a wavelength of less than about 400 nanometers and at least 50% of said electromagnetic radiation having a wavelength of greater than about 800 nanometers, respectively.

12. The omnidirectional UV-IR reflector of claim 11, wherein said first omnidirectional reflection band and said second omnidirectional reflection band reflect at least 75% of said electromagnetic radiation having a wavelength of less than about 400 nanometers and at least 75% of said electromagnetic radiation having a wavelength of greater than about 800 nanometers, respectively.

13. The omnidirectional UV-IR reflector of claim 9, wherein said omnidirectional transparency band is greater than 80% transparent for electromagnetic radiation having a wavelength between about 400 to 800 nanometers.

14. The omnidirectional UV-IR reflector of claim 13, wherein said omnidirectional transparency band is greater than 90% transparent for electromagnetic radiation having a wavelength between about 400 to 800 nanometers.

15. The omnidirectional UV-IR reflector of claim 9, wherein said multilayer stack reflects greater than 50% of electromagnetic radiation having wavelengths between about 800 and 1400 nanometers.

16. The omnidirectional UV-IR reflector of claim 9, wherein said multilayer stack reflects greater than 75% of electromagnetic radiation having wavelengths between about 800 and 1400 nanometers.

17. A process for omnidirectionally reflecting UV and IR electromagnetic radiation, the process comprising:

providing a multilayer stack having at least three layers, the at least three layers having at least one first index of refraction material layer H1 and at least two second index of refraction layers L1 and L2, the at least one first index of refraction material layer and the at least two second index of refraction material layers alternately stacked on top of each other;

the at least three layers each having a predefined thickness of d_H1, d_L1, d_{L2 with the dL1} thickness not generally equal to the d_L2 thickness such that the multilayer stack has a non-periodic layered structure;

wherein the multilayer stack, at incident angles between 0 to 45 degrees, has a first omnidirectional reflection band for electromagnetic radiation having a wavelength of less than about 400 nanometers, a second omnidirectional reflection band for electromagnetic radiation having a wavelength of greater than about 800 nanometers, and an omnidirectional transparency band between the first omnidirectional reflection band and the second omnidirectional reflection band;

providing a source of broadband electromagnetic radiation;

exposing the multilayer stack to the source of broadband electromagnetic radiation; and

reflecting at least 50% of the electromagnetic radiation having a wavelength of less than about 400 nanometers and at least 50% of the electromagnetic radiation having a wavelength of greater than about 800 nanometers.

18. The process of claim 17, wherein the multilayer stack, at incident angles between 0 to 45 degrees, is transparent to at least 20% of the electromagnetic radiation having a wavelength of about 850 nanometers.

19. The process of claim 17, further including reflecting at least 75% of the electromagnetic radiation having a wavelength of less than about 400 nanometers and at least 75% of the electromagnetic radiation having a wavelength of greater than about 800 nanometers.

20. The process of claim 17, wherein the multilayer stack is transparent to at least 80% of the electromagnetic radiation having a wavelength between about 400 to 800 nanometers.

21. The process of claim 17, further including reflecting greater than 75% of electromagnetic radiation having wavelengths between about 800 and 1400 nanometers.