Researchers have pioneered a 3D-SPI method that allows high-resolution imaging of microscopic objects, offering a transformative approach for biomedical research and optical sensing in the future.
A research team led by Professor Li Gong of the University of Science and Technology (USTC) of the Chinese Academy of Sciences (CAS) and collaborators developed a single-pixel imaging (3D-SPI) approach based on 3D light. Field illumination (3D-LFI), which enables volumetric imaging of microscopic objects at near-diffraction 3D optical resolution. They also demonstrated its ability to visualize 3D label-free optical absorption anisotropy by imaging single algal cells in vivo.
The study titled “Single Pixel Optical Volumetric Imaging by 3D Optical Field Illumination” was recently published in the journal Proceedings of the National Academy of Sciences (PNAS).
Advantages of SPI
Single pixel imaging (SPI) has become an attractive 3D imaging method. With single-pixel detectors instead of conventional sensors, SPI performance exceeds conventional performance in spectral range, detection efficiency, and timing response. Moreover, single-cell cameras outperform traditional imaging methods with low density, single-cell cameras.Photon Level, exact timing accuracy.
Challenges and achievements
3D-SPI techniques generally rely on time-of-flight (TOF) or stereo vision to extract depth information. However, current applications can only reach the millimeter level at best, which is not capable of imaging microscopic objects such as cells.
To push the limits of accuracy, the researchers built a 3D prototype – the LFI-SPM. As a result, the prototype achieves an imaging size of ~390 x 390 x 3,800 µm3 and a precision of 2.7 µm horizontally and 37 µm axially. They did a 3D photo shoot of the living without the stickers cocci pluvialis cells and successfully counted live cells in situ.
As expected, this approach can be applied to visualize different absorbance anisotropies of biological samples. With the ability to image in depth, scientists may be able to monitor cell morphology and growth in situ in the future. The research opens the door for high-performance 3D SPI with applications in biomedical research and optical sensing.
Reference: “Single-pixel optical volumetric imaging by 3D light-field illumination” By Yifan Liu, Panpan Yu, Yijing Wu, Jinghan Zhuang, Ziqiang Wang, Yinmei Li, Puxiang Lai, Jinyang Liang, Lei Gong, July 24, 2023, Available here. Proceedings of the National Academy of Sciences.