A solid state-imaging element including photoelectric conversion element and an optical element such as a photonic crystal is disclosed. The optical element is formed on the photoelectric conversion element, and has a refractive index periodic structure made up of stacked layers of materials with different refractive indices. The refractive index periodic structure is defined by multiple layers along a stacking direction and by a group of concentric similar shapes along an in-plane direction. The optical element may be fabricated via lithography and etching, or an autocloning technique. A solid state-imaging device including an arrangement of several solid-state imaging elements is also disclosed.