OPTICAL MEMBER WITH POROUS GLASS LAYER, IMAGE PICKUP APPARATUS, AND METHOD FOR MANUFACTURING OPTICAL MEMBER

摘要

To provide an optical member in which crystallization is suppressed and which has a porous glass layer on a base material. An optical member has a base material (1) and a porous glass layer (2) which is formed on the base material (1) and has a three-dimensional through pore, in which the existence ratio of crystals of 0.2 micrometer or more in the porous glass layer (2) is 1.0% or lower. The optical member is manufactured by heating a glass powder layer at a temperature elevation rate of 50 degree/min or higher to form a base glass layer which is then phase separated and etched.