ANTIREFLECTION COATING AND OPTICAL ELEMENT USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an antireflection coating which has <=1% or <=0.5% reflectance and enables the production yield to be enhanced in anticipation of variance in the characteristics and to provide an optical element having the antireflection coating. SOLUTION: The antireflection coating has a first layer 11 made of a coating having a refractive index of n1 and an optical thickness coating d1 formed on a substantially transparent lens 10 having a refractive index n0 and has a second layer 12 made of a SiO2 coating having an optical thickness coating d2 formed on the first layer 11. The antireflection coating is formed in such a manner that n0 , n1 , d1 and d2 satisfy 1.42<=n0 <=1.53, 1.95<=n1 <=2.35, 0.40λ<=d1 <=0.44λ and 0.17λ<=d2 <=0.18λ wherein λis the center wavelength of the objective light for antireflection.