News

3D digital holograms on smartphones?

A photodiode detects the polarization of light in the near-infrared region without additional polarization filters

21.01.2022 - The new sensor – made by KIST researchers – can detect near-infrared light, as well as previously undetectable visible light, opening up new opportunities in various fields.

3D holograms may soon make their way into our daily lives. Until now, 3D holograms based on phase shifting holo­graphy method could be captured using a large, specialized camera with a polari­zing filter. However, a Korean research group has just developed techno­logy that can acquire holograms on mobile devices, such as smartphones.

The Korea Institute of Science and Techno­logy (KIST) recently announced that a research team led by Min-Chul Park and Do Kyung Hwang of the Center for Opto-Elec­tronic Materials and Devices, in colla­boration with a research team led by 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 and thus, the realization of a minia­turized holographic image sensor for 3D digital holograms, using the 2D semi­conductor materials: rhenium diselenide and tungsten dise­lenide.

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 research group developed a photodiode by stacking an n-type semi­conductor, rhenium diselenide, which exhibits a dif­ference in light absorption dependent on the linear polari­zation angle of light in the near-infrared region, and a p-type semi­conductor, tungsten diselenide, which exhibits no difference in photo-response depen­dent on polari­zation, but enables superior per­formance. 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 success­fully capture holograms.

Do Kyung Hwang said, “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.” In addition, Min-Chul Park remarked, “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.” (Source: KIST)

Reference: J. Ahn et al.: Near-Infrared Self-Powered Linearly Polarized Photodetection and Digital Incoherent Holography Using WSe2/ReSe2 van der Waals Heterostructure, ACS Nano 15, 17917 (2021); DOI: 10.1021/acsnano.1c06234

Link: Center of Optoelectronic Materials and Devices, Post-Silicon Semiconductor Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea

Digital tools or software can ease your life as a photonics professional by either helping you with your system design or during the manufacturing process or when purchasing components. Check out our compilation:

Proceed to our dossier

Digital tools or software can ease your life as a photonics professional by either helping you with your system design or during the manufacturing process or when purchasing components. Check out our compilation:

Proceed to our dossier