Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth Imaging
Depth imaging is very important for many emerging technologies, such as artificial intelligence, driverless vehicles and facial recognition. However, all these applications demand compact and low-power systems that are beyond the capabilities of most state-of-art depth cameras. Recently, metasurface...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/13/4/607 |
| _version_ | 1797444784088940544 |
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| author | Zhiyuan Ma Siyu Dong Xiong Dun Zeyong Wei Zhanshan Wang Xinbin Cheng |
| author_facet | Zhiyuan Ma Siyu Dong Xiong Dun Zeyong Wei Zhanshan Wang Xinbin Cheng |
| author_sort | Zhiyuan Ma |
| collection | DOAJ |
| description | Depth imaging is very important for many emerging technologies, such as artificial intelligence, driverless vehicles and facial recognition. However, all these applications demand compact and low-power systems that are beyond the capabilities of most state-of-art depth cameras. Recently, metasurface-based depth imaging that exploits point spread function (PSF) engineering has been demonstrated to be miniaturized and single shot without requiring active illumination or multiple viewpoint exposures. A pair of spatially adjacent metalenses with an extended depth-of-field (EDOF) PSF and a depth-sensitive double-helix PSF (DH-PSF) were used, using the former metalens to reconstruct clear images of each depth and the latter to accurately estimate depth. However, due to these two metalenses being non-coaxial, parallax in capturing scenes is inevitable, which would limit the depth precision and field of view. In this work, a bifunctional reconfigurable metalens for 3D depth imaging was proposed by dynamically switching between EDOF-PSF and DH-PSF. Specifically, a polarization-independent metalens working at 1550 nm with a compact 1 mm<sup>2</sup> aperture was realized, which can generate a focused accelerating beam and a focused rotating beam at the phase transition of crystalline and amorphous Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub> (GST), respectively. Combined with the deconvolution algorithm, we demonstrated the good capabilities of scene reconstruction and depth imaging using a theoretical simulation and achieved a depth measurement error of only 3.42%. |
| first_indexed | 2024-03-09T13:17:34Z |
| format | Article |
| id | doaj.art-85387235873f4fc4959ec2c0d119f983 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-09T13:17:34Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-85387235873f4fc4959ec2c0d119f9832023-11-30T21:34:20ZengMDPI AGMicromachines2072-666X2022-04-0113460710.3390/mi13040607Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth ImagingZhiyuan Ma0Siyu Dong1Xiong Dun2Zeyong Wei3Zhanshan Wang4Xinbin Cheng5MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, ChinaMOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, ChinaMOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, ChinaMOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, ChinaMOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, ChinaMOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, ChinaDepth imaging is very important for many emerging technologies, such as artificial intelligence, driverless vehicles and facial recognition. However, all these applications demand compact and low-power systems that are beyond the capabilities of most state-of-art depth cameras. Recently, metasurface-based depth imaging that exploits point spread function (PSF) engineering has been demonstrated to be miniaturized and single shot without requiring active illumination or multiple viewpoint exposures. A pair of spatially adjacent metalenses with an extended depth-of-field (EDOF) PSF and a depth-sensitive double-helix PSF (DH-PSF) were used, using the former metalens to reconstruct clear images of each depth and the latter to accurately estimate depth. However, due to these two metalenses being non-coaxial, parallax in capturing scenes is inevitable, which would limit the depth precision and field of view. In this work, a bifunctional reconfigurable metalens for 3D depth imaging was proposed by dynamically switching between EDOF-PSF and DH-PSF. Specifically, a polarization-independent metalens working at 1550 nm with a compact 1 mm<sup>2</sup> aperture was realized, which can generate a focused accelerating beam and a focused rotating beam at the phase transition of crystalline and amorphous Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub> (GST), respectively. Combined with the deconvolution algorithm, we demonstrated the good capabilities of scene reconstruction and depth imaging using a theoretical simulation and achieved a depth measurement error of only 3.42%.https://www.mdpi.com/2072-666X/13/4/607metalensdepth imagingreconfigurable metasurfacepoint spread function |
| spellingShingle | Zhiyuan Ma Siyu Dong Xiong Dun Zeyong Wei Zhanshan Wang Xinbin Cheng Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth Imaging Micromachines metalens depth imaging reconfigurable metasurface point spread function |
| title | Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth Imaging |
| title_full | Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth Imaging |
| title_fullStr | Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth Imaging |
| title_full_unstemmed | Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth Imaging |
| title_short | Reconfigurable Metalens with Phase-Change Switching between Beam Acceleration and Rotation for 3D Depth Imaging |
| title_sort | reconfigurable metalens with phase change switching between beam acceleration and rotation for 3d depth imaging |
| topic | metalens depth imaging reconfigurable metasurface point spread function |
| url | https://www.mdpi.com/2072-666X/13/4/607 |
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