Optical element, optical lowpass filter, and solid-state imaging device

Abstract

To provide an optical element, an optical lowpass filter, and a solid-state imaging device of which quality and capability are hard to deteriorate even if they are continually subject to both of a high-temperature, high-humid environment and a normal environment. An optical lowpass filter includes a first birefringent plate, an IR-cut glass, a ¼ retardation film, a second birefringent plate, and a pressure sensitive adhesive as a bonding layer bonding these members. The pressure sensitive adhesive primarily contains a pressure sensitive adhesive main agent polymer composed of a monomer including many hydrophilic groups so as to enhance permeableness of water within the pressure sensitive adhesive. In addition, by selecting a mixing weight ratio of the pressure sensitive adhesive main agent polymer, the permeableness can be further enhanced. Therefore, such an optical element and an optical component can be obtained that are hard to become white turbid under the high-humidity environment by making the pressure sensitive adhesive thereof have efficient and saturated water; and that discharge water that is inside the pressure sensitive adhesive from the periphery thereof to the air so as to recover their optical properties in a short period of time under the normal environment.