This feature issue of Applied Optics is dedicated to the international meeting of Information Photonics 2020 (IP’20), which was held September 11–12, 2020, in Taipei, Taiwan. IP’20 covered a broad range of topics, including advanced display techniques, optical computing, and optical storage. This feature issue, however, limits topics to unconventional imaging techniques, such as digital holography, artificial-intelligence associated imaging, compressive imaging, and single-pixel imaging.
© 2021 Optical Society of America
The Information Photonics (IP) meeting got its start in the U.S., first in Aspen, Colorado, in 1999, as the succeeding meeting of Optics in Computing, organized by the Optical Society of America (OSA). Subsequent IP meetings were held in Lake Tahoe, Nevada, in 2001, Washington, D.C., in 2003, and Charlotte, North Carolina, in 2005. The following IP meeting was held at Awaji, Japan in 2008, organized by the Group of Information Photonics of the Optical Society of Japan. After that, the IP meetings were continued at Ottawa, Canada, in 2011, and Warsaw, Poland, in 2013. In 2019, the IP meeting (IP’19) was restarted as a sub-conference of Optics & Photonics International Congress at Yokohama, Japan. In IP’19, IP 2020 (IP’20) was determined to be held in Taiwan. Unfortunately, the COVID-19 epidemic disturbed some of the plans, and IP’20 was almost discontinued. Nevertheless, as the epidemic in Taiwan slowed down in August, the General Chair, Prof. Chau-Jern Cheng, decided to go on. Eventually, the IP’20 was successfully held in a hybrid form, both in person and online, September 11–12, 2020, at National Taiwan Normal University in Taipei, Taiwan.
The scope of IP covers the use of optics and photonics for information optoelectronics and applied research. Topics include optical computing, information processing, digital optics, nanophotonic information system, optical biomimetic computing, optical cryptology, computer-generated holography, three-dimensional and volumetric displays, light-field technique, digital holography, quantitative phase imaging, computational imaging, compressive imaging, adaptive imaging, optical memory, etc. In IP’20, the number of accepted papers was 70, including 4 keynote talks, 25 oral presentations (including contributed papers and invited papers), and 41 poster presentations. The total participants are 199 from 12 countries, as shown in Fig. 1. The next IP meeting will be held at Yokohama, Japan, in April 2022.
Although information photonics covers a wide range of categories, this feature issue focuses on a relatively narrow topic. The term unconventional imaging (UI) encompasses techniques that are not based solely on images generated by geometrical optics. Computational process is primarily involved in the UI systems, and the retrieved image can be high-dimensional. Typical UI techniques include single-pixel imaging, light-field technique, digital holography, compressive imaging, structured illumination imaging, ptychography, lensless imaging, and ultrafast imaging. In addition, artificial intelligence-associated imaging is also an explosive topic of UI. We have sought to bring the methods and applications of unconventional imaging to the forefront in order to explore the state of the art and shake up the field of modern imaging. In creating this feature issue, one of our objectives is to promote the development of modern imaging techniques and to speed up the progress of industry applications. As a result, this feature issue contains 2 review papers, 6 invited papers, and 11 research papers. We thank all the contributors for their continuing dedication and the role they have played in advancing the science and technology of modern imaging techniques. We also thank the staff of Applied Optics for their support throughout the creation of this feature issue.