Optical member and method for manufacturing optical member

Abstract

An optical member includes a base material and an antireflective layer on the base material wherein the antireflective layer includes a plurality of fine protrusions on a surface thereof and a support layer for supporting the protrusions, and the support layer contains boron in an amount of 7×1019 atoms/cm3 or more and 2.5×1020 atoms/cm3 or less.

What is claimed is: 
     
         1 . An optical member comprising:
 a transparent base;   a plurality of protrusions disposed on the transparent base; and   an amorphous layer disposed between the transparent base and the plurality of protrusions,   wherein the plurality of protrusions are formed from crystals of aluminum oxide, and   wherein the amorphous layer contains aluminum oxide and boron.   
     
     
         2 . The optical member according to  claim 1 , wherein the amorphous layer is porous. 
     
     
         3 . The optical member according to  claim 2 , wherein a porosity of the amorphous layer is 20% or more and 45% or less. 
     
     
         4 . The optical member according to  claim 1 , wherein a thickness of the amorphous layer is 10 nm or more and 100 nm or less. 
     
     
         5 . The optical member according to  claim 1 , wherein a boron content of the amorphous layer is 7×10 19  atoms/cm 3  or more and 2.5×10 20  atoms/cm 3  or less. 
     
     
         6 . The optical member according to  claim 1 , wherein the crystals of aluminum oxide include boehmite crystal. 
     
     
         7 . The optical member according to  claim 1 , wherein a width at a height that is a half of a height of one of the plurality of protrusions is 5 nm or more and 50 nm or less. 
     
     
         8 . The optical member according to  claim 1 , wherein the optical member has an average surface roughness Ra′ of 15 nm or more and 100 nm or less. 
     
     
         9 . The optical member according to  claim 1 , wherein a distance from a surface of the transparent base to a top of one of the plurality of protrusions is 50 nm or more and 1000 nm or less. 
     
     
         10 . The optical member according to  claim 1 , wherein a reflectance of the optical member at light wavelengths between 530 nm to 570 nm is 0.1% or less. 
     
     
         11 . The optical member according to  claim 1 , wherein a material of the transparent base is glass. 
     
     
         12 . The optical member according to  claim 1 , wherein a material of the transparent base is plastic. 
     
     
         13 . The optical member according to  claim 1 , wherein the transparent base is a lens. 
     
     
         14 . The optical member according to  claim 1 , wherein the transparent base is a cover. 
     
     
         15 . A display comprising the optical member according to  claim 1 . 
     
     
         16 . A camera comprising the optical member according to  claim 1 . 
     
     
         17 . A photographing optical system comprising the optical member according to  claim 1 . 
     
     
         18 . An observing optical system comprising the optical member according to  claim 1 . 
     
     
         19 . A projecting optical system comprising the optical member according to  claim 1 . 
     
     
         20 . A scanning optical system comprising the optical member according to  claim 1 .