UV-BLOCKING COATING WITH CAPPING LAYER FOR OPTICS

• US 20170052294A1
• Filed: 08/05/2016
• Published: 02/23/2017
• Est. Priority Date: 08/18/2015
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Cangemi, Michael Jerome, Oudard, Jean-Francois
• Granted Patent: US 10,459,134 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B29D 11/00009 Production of simple or compound lenses
• CPC Class Codes: C09J 2400/10 Presence of inorganic materials
• CPC Class Codes: C09J 5/02 involving pretreatment of the surfaces to be joined
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 13/143 for use with ultraviolet radiation
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G02B 5/22 Absorbing filters G02B5/201 - G02B5/208 take precedence
• CPC Class Codes: G02B 7/025 using glue

Abstract

An optical assembly and a method for making the optical assembly. The optical assembly includes an optical element; a blocking coating; a capping layer on the blocking coating; a holder; and an adhesive configured to adhere the optical element to the holder. The blocking coating includes a light absorber that does not transmit light with wavelengths from greater than or equal to about 250 nm to less than or equal to about 400 nm; The light absorber is positioned such that light having a wavelength from greater than or equal to about 190 nm to less than or equal to about 500 nm is not incident to the adhesive. The capping layer is made from a material having high transmission in the UV and enables use of aggressive cleaning treatments on the optical element significant impairment of the UV transmission of the optical element.

Claims

1. An optical assembly comprising:

an optical element;

a blocking coating in contact with the optical element, the blocking coating including a light absorber that does not transmit light with wavelengths from greater than or equal to about 190 nm to less than or equal to about 500 nm; and

a capping layer, the light absorber being positioned between the capping layer and the optical element.

2. The optical assembly of claim 1, wherein the blocking coating further includes an anti-reflective layer positioned between the optical element and the light absorber.

3. The optical assembly of claim 2, wherein the anti-reflective layer comprises a material selected from the group consisting of metal oxides, metal nitrides, metal carbides, and mixtures thereof.

4. The optical assembly of claim 1, wherein the light absorber comprises one or more materials selected from the group consisting of chromium, titanium, zinc, nickel, manganese, iron, niobium, silver, gold, halfnium, aluminum, tantalum, oxides thereof, nitrides thereof, and carbides thereof.

5. The optical assembly of claim 1, wherein the capping layer is in direct contact with the blocking coating.

6. An optical assembly comprising:

an optical element;

a holder for the optical element;

a blocking coating positioned between the optical element and the holder, the blocking coating including a light absorber that does not transmit light with wavelengths from greater than or equal to about 190 nm to less than or equal to about 500 nm;

a capping layer positioned between the light absorber and the holder; and

an adhesive configured to adhere the optical element to the holder;

wherein the light absorber is positioned such that light having a wavelength from greater than or equal to about 190 nm to less than or equal to about 500 nm is not incident to the adhesive.

7. The optical assembly of claim 6, wherein the optical element is a lens.

8. The optical assembly of claim 6, wherein the blocking coating further includes an anti-reflective layer positioned between the light absorber and the optical element.

9. The optical assembly of claim 8, wherein the anti-reflective layer comprises a material selected from the group consisting of metal oxides, metal nitrides, metal carbides, and mixtures thereof.

10. The optical assembly of claim 8, wherein the anti-reflective layer has a reflectance of less than or equal to about 20% for light with wavelengths of from greater than or equal to about 190 nm to less than or equal to about 500 nm.

11. The optical assembly of claim 6, wherein the light absorber comprises one or more materials selected from the group consisting of chromium, titanium, zinc, nickel, manganese, iron, niobium, silver, gold, hafnium, aluminum, tantalum, oxides thereof, nitrides thereof, and carbides thereof.

12. The optical assembly of claim 6, wherein the capping layer is in direct contact with the adhesive.

13. The optical assembly of claim 6, wherein the capping layer comprises a material selected from the group consisting of SiO₂, metal oxides, metal nitrides, and metal carbides.

14. The optical assembly of claim 6, wherein the capping layer has a transmittance, per mm thickness, at each wavelength in the range from 225 nm-380 nm of at least 85%.

15. The optical assembly of claim 6, wherein the capping layer has a transmittance, per mm thickness, at each wavelength in the range from 225 nm-380 nm of at least 95%.

16. The optical assembly of claim 6, wherein the optical element comprises CaF₂, the light absorber comprises Cr, and the capping layer comprises SiO₂.

17. The optical assembly of claim 6, further comprising an adhesion promoter positioned between the light absorber and the optical element.

18. The optical assembly of claim 17, wherein the optical element comprises a fluoride material and the adhesion promoter comprises a fluoride material.

19. The optical assembly of claim 17, wherein optical element comprises CaF₂ and the adhesion promoter comprises MgF₂.

20. A method for reducing degradation of an adhesive in a optical assembly, the method comprising:

applying a blocking coating to an optical element, the blocking coating including a light absorber that does not transmit light with wavelengths from greater than or equal to about 190 nm to less than or equal to about 500 nm;

applying a capping layer to the blocking coating, the capping layer comprising SiO₂ or a metal oxide material;

applying an adhesive to the capping layer; and

configuring the light absorber and the adhesive so that light with wavelengths from greater than or equal to about 190 nm to less than or equal to about 500 nm is not incident to the adhesive.