| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve the durability compared with a conventional type without reducing the transmissivity of light. <P>SOLUTION: An antireflection coating 6 provided on a lens 5 which passes through at least two wavelengths of light in the wavelength range of 1,300 to 1,600 nm, wherein the antireflection coating comprises: two high refractive index layers 60 and 62; two low refractive index layers 63 and 65 having a refractive index lower than the refractive index of the high refractive index layers 60 and 62; and two supplementary layers 61 and 64 having a composition different from the composition of the high refractive index layers 60 and 62 and from the composition of the low refractive index layers 63 and 65, and being provided adjacent to the high refractive index layers 60 and 62 or to the low refractive index layers 63 and 65. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
