Development of a holographic image sensor for 3D digital holograms on mobile devices

3D holograms, previously only seen in science fiction movies, may soon find their way into our daily lives. Until now, 3D holograms based on the phase shift holography method could be captured using a large specialized camera with a polarizing filter. However, a Korean research group has just developed a technology capable of acquiring holograms on mobile devices, such as smartphones.

The Korea Institute of Science and Technology (KIST, Director Seok-jin Yoon) recently announced that a research team led by Dr. Min-Chul Park and Dr. Do Kyung Hwang from the Center for Opto-Electronic Materials and Devices, in collaboration with a research team led by Professor Seongil Im from the Department of Physics of Yonsei University, succeeded in developing a photodiode that detects the polarization of near-infrared light without additional polarization filters and thus, the realization of a miniaturized holographic image sensor for 3D digital holograms, using 2D semiconductor materials: rhenium diselenide and tungsten diselenide.

Photodiodes, which convert light into current signals, are essential components in the pixels of image sensors in digital cameras and smartphones. The introduction of the ability to detect the polarization of light to the image sensor of an ordinary camera provides a variety of new information, enabling the storage of 3D holograms. Previous bias detection cameras have an additional bias filter, several hundred micrometers in size, attached to an ultra-small optical diode image sensor, less than a micrometer in size. Thus, they could not be implemented in portable electronic devices due to their inability to be integrated and miniaturized.

The research group developed a photodiode by stacking an n-type semiconductor, rhenium diselenide, which exhibits a difference in light absorption as a function of the linear polarization angle of near-infrared light ( 980 nm), and a p-type semiconductor, tungsten diselenide, which exhibits no difference in photo-response as a function of polarization, but allows superior performance. The device is excellent at photodetecting various wavelengths ranging from ultraviolet to near-infrared, and is even capable of selectively detecting polarization characteristics of light in the near-infrared region. The research group used the device to create a digital holographic image sensor that records polarization characteristics to successfully capture holograms.

KIST’s Dr. Hwang said: “Research on downsizing and integrating individual elements is needed to ultimately miniaturize holographic systems. The results of our research will lay the foundation for the future development of miniaturized holographic camera sensor modules.“Furthermore,” Dr. Park remarked, “The new sensor can additionally detect near-infrared light, as well as previously undetectable visible light, opening up new opportunities in various fields such as 3D night vision, autonomous driving, biotechnology and near-infrared data acquisition for the analysis and restoration of cultural property. .”

Korea Institute of Science and Technology (KIST). Founded as the first government-funded multidisciplinary research institute in Korea, KIST established a national development strategy based on science and technology and disseminated various core industrial technologies. Now, half a century later, KIST is raising Korea’s status in science and technology through cutting-edge fundamental technology R&D. Looking to the future, KIST will continue to strive to be a leading research institute, pursuing a better future for Korea and all of humanity.

This research was supported by the Korean Ministry of Science and ICT (Minister Heysook Lim) as KIST Institutional R&D Projects and by the Korean Ministry of Culture, Sports and Tourism (Minister Hwang, Hee) as as an R&D project on Korea’s cultural technologies. Creative Content Agency – Culture, Arts, Sports and Tourism Technology Promotion Center. The results were published in the November issue of ACS Nano (IF: 15.881).

Source: https://www.nst.re.kr/nst_en/

Michael C. Garrison