The following section is the special issue for the 12th International Conference on Optics-photonics Design and Fabrication (ODF’20 in 2021) held on June 1st–3rd, 2021 originally at Taoyuan, Taiwan. Due to COVID-19, it was postponed a year and was changed into an all-virtual web conference format. The special section contains contributed papers based on the presentations at ODF’20 in 2021. These papers were reviewed and accepted according to the editorial policy of Optical Review.

The ODF conference has been held biyearly since 1998 and is an international forum for engineers and scientists in the field of optics-photonics design and fabrication to exchange their ideas and achievements to promote future progress in the field. This special issue covers wide range of optical technologies from design, prototyping, and fabrication of optical devices, components, and systems.

ODF’20 in 2021 was organized by Optics Design Group of the Optical Society of Japan and National Central University/Taiwan. It was sponsored by the Japan Society of Applied Physics, Asia Optical Co., Inc./Taiwan, Cybernet Systems Taiwan Co., Ltd., Ministry of Science and Technology/Taiwan, Photonics Industry & Technology Development Association/Taiwan, and Taiwan Photonics Society. We sincerely thank 31 other organizations for their cooperation.

At ODF’20 in 2021, the plenary session, a special session on “AR/VR/MR Optics” and the four sessions on Optical Design/Simulation, Optical Components/Devices, Optical Systems and New Technologies were provided. The total number of papers reached 195, and the total number of participants was 931 from 22 countries. The conference was successful and is followed by the 13th International Conference on Optics-photonics Design and Fabrication (ODF’22) to be held in Sapporo, Japan, on August 3rd–5th, 2022.

Finally, we would like to express our sincere gratitude to all who contributed to ODF’20 in 2021 and the Editor’s thank goes to honest reviewers for their fair judgments.

April 2022.

Editor in Chief of Special Section

Kenji Konno