LENS WITH BROADBAND ANTI-REFLECTIVE STRUCTURES FORMED BY NANO ISLAND MASK AND METHOD OF MAKING THE SAME

• US 20130155522A1
• Filed: 11/26/2012
• Published: 06/20/2013
• Est. Priority Date: 11/24/2011
• Status: Active Grant

• Current Assignee: Kaist
• Original Assignee: Kaist
• Inventors: JEONG, Ki-Hun, JUNG, Hyukjin
• Granted Patent: US 9,170,350 B2
• Time in Patent Office: Days
• US Class Current: 359/664
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 1/118 having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures
• CPC Class Codes: G02B 3/00 Simple or compound lenses
• CPC Class Codes: G02B 3/0006 Arrays G02B3/02, G02B5/188 take precedence
• CPC Class Codes: G02B 3/02 with non-spherical faces G02B3/10 takes precedence

Abstract

The present invention provides a lens having broadband anti-reflective nanostructures formed using nano-island masks and a method for making the same, in which nanostructures having a size and period equal to or smaller than the light wavelength are formed on the surface of a lens to obtain a lens having decreased reflectance, increased transmittance and high efficiency. The lens having broadband anti-reflective nanostructures formed using nano-island masks comprises: a lens having a planar shape or a predetermined curvature; and anti-reflective nanostructures formed on one surface of the lens using nano-island masks, in which the horizontal and vertical cross-sections of the anti-reflective nanostructures have a size equal to or smaller than the light wavelength.

Claims

1. A lens having broadband anti-reflective nanostructures formed using nano-island masks, the lens comprising:

a lens having a planar shape or a predetermined curvature; and

anti-reflective nanostructures formed on one surface of the lens using nano-island masks, in which the horizontal and vertical cross-sections of the anti-reflective nanostructures have a size equal to or smaller than the light wavelength.

2. The lens of claim 1, wherein the period of the anti-reflective nanostructures has a size equal to or smaller than the light wavelength.

3. The lens of claim 1, wherein the lens is formed of photoresist, a polymer, silicon, glass or a group III-V semiconductor compound.

4. The lens of claim 1, wherein the lens has a spherical or non-spherical surface shape.

5. The lens of claim 1, wherein the lens consists of a plurality of lenses.

6. The lens of claim 1, wherein the lens is applied to an image device, an optical sensor or a projection lens.

7. A method for making a lens having broadband anti-reflective nanostructures formed using nano-island masks, the method comprising the steps of:

applying a mask material to the surface of a lens (mask material evaporation step);

forming the mask material into particles to form nano-islands (particle formation step);

etching the lens surface using the nano-islands using masks (etching step); and

removing the nano-islands from the lens to form anti-reflective nanostructures on the lens (nano-island removal step).

8. The method of claim 7, wherein the mask material that is applied to the lens surface in the mask material evaporation step is a metal or an alloy of two or more metals selected from the group consisting of silver, gold, platinum, aluminum, iron, zinc, copper, tin, bronze, brass and nickel.

9. The method of claim 7, wherein the mask material that is applied to the lens surface in the mask material evaporation step is any one or more materials selected from the group consisting of oxides, including SiO₂, TEOS (tetraethyl orthosilicate), ITO (indium tin oxide) and Al₂O₃, nitrides, including TiN and SiNx, low-molecular-weight compounds, including parylene, polymers, and carbon compounds, including CNTs (carbon nanotubes), graphite and graphene.

10. The method of claim 7, wherein the mask material in the particle formation step is formed into particles in an atmosphere of any one or more gases of inert gases, including nitrogen, argon, helium, neon, krypton or xenon, or a vacuum or air atmosphere.

11. The method of claim 7, wherein the particle formation in the particle formation step is performed using heat treatment, laser processing or electromagnetic wave irradiation.

12. The method of claim 11, wherein the heat treatment is performed using heat or convection current.

13. The method of claim 11, wherein the heat treatment is performed at a temperature between 30 and 2,000°

C.

14. The method of claim 11, wherein the heat treatment is performed at a temperature between 30 and 300°

C.

15. The method of claim 7, wherein the etching step is performed by etching the lens surface using isotropic or anisotropic etching.

16. The method of claim 7, wherein the horizontal and vertical cross-sections of the anti-reflective nanostructures in the nano-island removal step have a size equal to or smaller than the light wavelength.

17. The method of claim 7, wherein the period of the anti-reflective nanostructures in the nano-island removal step has a size equal to or smaller than the light wavelength.