Optical design method and diffractive optical element

An optical design and manufacturing method comprising:

• a setting step of setting a first step pattern provided to a binary optic based on optical design of a configuration in which the binary optic and a conventional lens are used in combination;
• a first calculating step of calculating first phase data indicating a relation of a phase to a shape of a meta-atom based on a preliminarily set first wavelength;
• a first identifying step of calculating a first phase pattern from the first step pattern and identifying a fine pattern indicating the shape of the meta-atom corresponding to the first phase pattern by referring to the first phase data;
• a second calculating step of calculating second phase data different from the first phase data based on a preliminarily set second wavelength different from the first wavelength;
• a second identifying step of identifying a second phase pattern corresponding to the fine pattern by referring to the second phase data;
• a designing step of designing the conventional lens based on the second phase pattern for achieving optical design of the configuration in which a metalens having the fine pattern and the conventional lens are used in combination, and
• a producing step of producing the metalens based on the configuration designed through the designing step, wherein
• the first calculating step calculates the first phase data using optical software of a vector model,
• the designing step designs the conventional lens by optimizing only the conventional lens using optical design software for optical tracking without repeating calculations using the optical software of the vector model on the metalens.