11 Jan 2022
Korea based team says 3D digital holograms are enabled by a new type of polarization image sensor.
The Korea Institute of Science and Technology (KIST, directed by Seok-jin Yoon) last week announced that a research team led by Dr. Min-Chul Park and Dr. Do Kyung Hwang of the Center for Opto-Electronic Materials and Devices, in collaboration with a research team led by Prof. Seongil Im of the Department of Physics at Yonsei University, was successful in developing a photodiode that detects the polarization of light in the near-infrared region without additional polarization filters.
By this means the team has been able to realize a miniaturized holographic image sensor for 3D digital holograms, using the 2D semiconductor materials rhenium diselenide and tungsten diselenide. The work is described in ACS Nano.
Photodiodes, which convert light into current signals, are essential components within the pixels of image sensors in digital and smartphone cameras. Introducing the ability to sense 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 polarization-sensing cameras have an additional polarization 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 into portable electronic devices because of their inability to be integrated and miniaturized.
The device is excellent in the photodetection of various wavelengths from ultraviolet to near-infrared, even capable of selectively detecting the polarization characteristics of light in the near-infrared region. The research group utilized the device to create a digital holographic image sensor that records polarization characteristics to capture holograms.
Dr. Hwang of KIST commented, “Research on the downsizing and integration of individual elements is required to ultimately miniaturize holographic systems. The results of our research will lay the foundation for the future development of miniaturized holographic camera sensor modules.”
Dr. Park added, “The new sensor can further detect near-infrared light, as well as previously undetectable visible light, opening up new opportunities in various fields such as 3D night vision, self-driving, biotechnology, and near-infrared data acquisition for analyzing and restoring cultural assets.”