Optical element, image sensor, and image pickup apparatus

An image sensor comprising:

• an optical element;
• and
• a photoelectric converter configured to convert light from the optical element into electric charges,
• wherein the optical element includes:
• a substrate;
• and
• a concavo-convex structure formed on the substrate,
• wherein the concavo-convex structure has a plurality of structures that are periodically arranged and include at least one of a concave element and a convex element,
• wherein a plurality of annuli arranged along a radial direction of the substrate are formed on the substrate,
• wherein each of the plurality of annuli includes, along the radial direction, a first region and a second region having a phase smaller than that of the first region,
• wherein the plurality of structures include a plurality of first structures disposed in the first region and a plurality of second structures disposed in the second region, and
• wherein a base layer is provided between the substrate and at least one of the plurality of second structures.

An image pickup apparatus comprising:

• an optical system;
• and
• an image sensor configured to receive an image formed by the optical system,
• wherein the optical system includes a plurality of optical elements that includes an optical element that includes:
• a substrate;
• and
• a concavo-convex structure formed on the substrate,
• wherein the concavo-convex structure has a plurality of structures that are periodically arranged and include at least one of a concave element and a convex element,
• wherein a plurality of annuli arranged along a radial direction of the substrate are formed on the substrate,
• wherein each of the plurality of annuli includes, along the radial direction, a first region and a second region having a phase smaller than that of the first region,
• wherein the plurality of structures include a plurality of first structures disposed in the first region and a plurality of second structures disposed in the second region, and
• wherein a base layer is provided between the substrate and at least one of the plurality of second structures.