Shenyu Zhu - Academia.edu (original) (raw)
Papers by Shenyu Zhu
Frontiers in Optics + Laser Science 2022 (FIO, LS)
We demonstrate compressive non-line-of-sight imaging with downsampling ratio of 6.25% by using a ... more We demonstrate compressive non-line-of-sight imaging with downsampling ratio of 6.25% by using a convolutional neural network (CNN). Photon arrival-time histogram with 10 picosecond resolution enables high-quality image reconstruction with CNN trained purely by using simulated dataset.
Physical Review Applied
In non-line-of-sight (NLOS) imaging, the spatial information of hidden targets is reconstructed f... more In non-line-of-sight (NLOS) imaging, the spatial information of hidden targets is reconstructed from the time-of-light (TOF) of the multiple bounced signal photons. The need for NLOS imagers to perform extensive scanning in the transverse spatial dimensions constrains the imaging speed and reconstruction quality while limiting their applications on static scenes. Utilizing a photon TOF histogram with picosecond temporal resolution, we develop compressive non-line-of-sight imaging enabled by deep learning. Two-dimensional images (32 × 32 pixels) of the NLOS targets can be reconstructed with superior reconstruction quality via a convolutional neural network (CNN), using significantly downscaled data (8 × 8 scanning points) at a downsampling ratio of 6.25% compared to the traditional methods. The CNN is end-to-end trained purely using simulated data but robust for image reconstruction with experiment data. Our results suggest that deep learning is effective for reducing the scanning points and total capture time towards scanningless NLOS imaging and videography.
Cornell University - arXiv, Oct 31, 2022
We demonstrate a photon-sensitive, three-dimensional camera by active near-infrared illumination ... more We demonstrate a photon-sensitive, three-dimensional camera by active near-infrared illumination and fast time-of-flight gating. It uses pico-second pump pulses to selectively up-convert the backscattered photons according to their spatiotemporal modes via sum-frequency generation in a χ 2 nonlinear crystal, which are then detected by electron-multiplying CCD with photon sensitive detection. As such, it achieves sub-millimeter depth resolution, exceptional noise suppression, and high detection sensitivity. Our results show that it can accurately reconstruct the surface profiles of occluded targets placed behind highly scattering and lossy obscurants of 14 optical depth (round trip), using only milliwatt illumination power. This technique may find applications in biomedical imaging, environmental monitoring, and wide-field light detection and ranging.
Photonics Research
We demonstrate a photon-sensitive, three-dimensional (3D) camera by active near-infrared illumina... more We demonstrate a photon-sensitive, three-dimensional (3D) camera by active near-infrared illumination and fast time-of-flight gating. It uses picosecond pump pulses to selectively upconvert the backscattered photons according to their spatiotemporal modes via sum-frequency generation in a χ 2 nonlinear crystal, which are then detected by an electron-multiplying CCD with photon sensitive detection. As such, it achieves sub-millimeter depth resolution, exceptional noise suppression, and high detection sensitivity. Our results show that it can accurately reconstruct the surface profiles of occluded targets placed behind highly scattering and lossy obscurants of 14 optical depth (round trip), using only milliwatt illumination power. This technique may find applications in biomedical imaging, environmental monitoring, and wide-field light detection and ranging.
Supplementary information on quantum parametric mode sorting
Applied Optics, 2021
We explore an active illumination approach to remote material recognition, based on quantum param... more We explore an active illumination approach to remote material recognition, based on quantum parametric mode sorting and single-photon detection. By measuring a photon’s time of flight at picosecond resolution, 97.8% recognition is demonstrated by illuminating only a single point on the materials. Thanks to the exceptional detection sensitivity and noise rejection, a high recognition accuracy of 96.1% is achieved even when the materials are occluded by a lossy and multiscattering obscurant.
Optics Express, 2021
Non-invasive optical imaging through opaque and multi-scattering media remains highly desirable a... more Non-invasive optical imaging through opaque and multi-scattering media remains highly desirable across many application domains. The random scattering and diffusion of light in such media inflict exponential decay and aberration, prohibiting diffraction-limited imaging. By non-interferometric few picoseconds optical gating of backscattered photons, we demonstrate single photon sensitive non-invasive 3D imaging of targets occluded by strongly scattering media with optical thicknesses reaching 9.5ls (19ls round trip). It achieves diffraction-limited imaging of a target placed 130 cm away through the opaque media, with millimeter lateral and depth resolution while requiring only one photon detection out of 50,000 probe pulses. Our single photon sensitive imaging technique does not require wavefront shaping nor computationally-intensive image reconstruction algorithms, promising practical solutions for diffraction-limited imaging through highly opaque and diffusive media with low illumination power.
2019 Conference on Lasers and Electro-Optics (CLEO), 2019
We demonstrate noise-tolerant 3D imaging with 8 dB noise rejection beyond the theoretical limit o... more We demonstrate noise-tolerant 3D imaging with 8 dB noise rejection beyond the theoretical limit of linear-optical matched filters. We perform the imaging from only 0.0006 detected signal photons per pulse despite being swamped by 50-folds stronger background noise. © 2019 The Author(s)
Conference on Lasers and Electro-Optics, 2021
We demonstrated a non-line-of-sight imaging and tracking system with picosecond optical-gated sin... more We demonstrated a non-line-of-sight imaging and tracking system with picosecond optical-gated single photon detection. It sees through obscureness while achiev-ing high resolution NLOS 3D imaging and position retrieval.
Quantum parametric mode sorting has been shown to enable photon counting with precise time gating... more Quantum parametric mode sorting has been shown to enable photon counting with precise time gating and exceptional noise rejection that significantly exceeds what is possible with linear filters. While previous experimental demonstrations were in a collinear optical configuration, its response to off-axis scattering must be understood to apply it more broadly in remote sensing missions. To evaluate this prospect, we use a laboratory testbed to examine its performance for detecting photons at small angles, along both forward and backward directions, after passing through strongly scattering media. Our results find no measurable degradation in detecting noncollinear photons along both directions. This finding indicates that the key intra-pulse coherence essential to quantum parametric mode sorting is maintained at a small scattering angle, permitting its applications on a moving platform.
Non-line-of-sight (NLOS) optical imaging and sensing of objects imply new capabilities valuable t... more Non-line-of-sight (NLOS) optical imaging and sensing of objects imply new capabilities valuable to autonomous technology, machine vision, and other applications. Existing NLOS imaging methods rely heavily on the prowess of computational algorithms to reconstruct the images from weak triply scattered signals. Here, we introduce a new approach to NLOS imaging and sensing using the picosecond gated single photon detection generated by quantum frequency conversion. With exceptional signal isolation, this approach can reliably sense obscured objects around the corner and substantially simplify the data processing needed for position retrieval and surface profiling. For each pixel, only 4×10−3 photons are needed to be detected per pulse to position and profile occluded objects with high resolution. Furthermore, the vibration frequencies of different objects can be resolved by analyzing the photon number fluctuation received within in a ten-picosecond window, allowing NLOS acoustic sensing...
2015 International Conference on Optical Instruments and Technology: Optoelectronic Imaging and Processing Technology, 2015
Microscopy research and technique, 2016
For the design of a passive autofocusing (AF) system for optical microscopes, many time-consuming... more For the design of a passive autofocusing (AF) system for optical microscopes, many time-consuming and tedious experiments have been performed to determine and design a better focus criterion function, owing to the sample-dependence of this function. To accelerate the development of the AF systems in optical microscopes and to increase AF speed as well as maintain the AF accuracy, this study proposes a self-adaptive and nonmechanical motion AF system. The presented AF system does not require the selection and design of a focus criterion function when it is developed. Instead, the system can automatically determine a better focus criterion function for an observed sample by analyzing the texture features of the sample and subsequently perform an AF procedure to bring the sample into focus in the objective of an optical microscope. In addition, to increase the AF speed, the Z axis scanning of the mechanical motion of the sample or the objective is replaced by focusing scanning performe...
Frontiers in Optics + Laser Science 2022 (FIO, LS)
We demonstrate compressive non-line-of-sight imaging with downsampling ratio of 6.25% by using a ... more We demonstrate compressive non-line-of-sight imaging with downsampling ratio of 6.25% by using a convolutional neural network (CNN). Photon arrival-time histogram with 10 picosecond resolution enables high-quality image reconstruction with CNN trained purely by using simulated dataset.
Physical Review Applied
In non-line-of-sight (NLOS) imaging, the spatial information of hidden targets is reconstructed f... more In non-line-of-sight (NLOS) imaging, the spatial information of hidden targets is reconstructed from the time-of-light (TOF) of the multiple bounced signal photons. The need for NLOS imagers to perform extensive scanning in the transverse spatial dimensions constrains the imaging speed and reconstruction quality while limiting their applications on static scenes. Utilizing a photon TOF histogram with picosecond temporal resolution, we develop compressive non-line-of-sight imaging enabled by deep learning. Two-dimensional images (32 × 32 pixels) of the NLOS targets can be reconstructed with superior reconstruction quality via a convolutional neural network (CNN), using significantly downscaled data (8 × 8 scanning points) at a downsampling ratio of 6.25% compared to the traditional methods. The CNN is end-to-end trained purely using simulated data but robust for image reconstruction with experiment data. Our results suggest that deep learning is effective for reducing the scanning points and total capture time towards scanningless NLOS imaging and videography.
Cornell University - arXiv, Oct 31, 2022
We demonstrate a photon-sensitive, three-dimensional camera by active near-infrared illumination ... more We demonstrate a photon-sensitive, three-dimensional camera by active near-infrared illumination and fast time-of-flight gating. It uses pico-second pump pulses to selectively up-convert the backscattered photons according to their spatiotemporal modes via sum-frequency generation in a χ 2 nonlinear crystal, which are then detected by electron-multiplying CCD with photon sensitive detection. As such, it achieves sub-millimeter depth resolution, exceptional noise suppression, and high detection sensitivity. Our results show that it can accurately reconstruct the surface profiles of occluded targets placed behind highly scattering and lossy obscurants of 14 optical depth (round trip), using only milliwatt illumination power. This technique may find applications in biomedical imaging, environmental monitoring, and wide-field light detection and ranging.
Photonics Research
We demonstrate a photon-sensitive, three-dimensional (3D) camera by active near-infrared illumina... more We demonstrate a photon-sensitive, three-dimensional (3D) camera by active near-infrared illumination and fast time-of-flight gating. It uses picosecond pump pulses to selectively upconvert the backscattered photons according to their spatiotemporal modes via sum-frequency generation in a χ 2 nonlinear crystal, which are then detected by an electron-multiplying CCD with photon sensitive detection. As such, it achieves sub-millimeter depth resolution, exceptional noise suppression, and high detection sensitivity. Our results show that it can accurately reconstruct the surface profiles of occluded targets placed behind highly scattering and lossy obscurants of 14 optical depth (round trip), using only milliwatt illumination power. This technique may find applications in biomedical imaging, environmental monitoring, and wide-field light detection and ranging.
Supplementary information on quantum parametric mode sorting
Applied Optics, 2021
We explore an active illumination approach to remote material recognition, based on quantum param... more We explore an active illumination approach to remote material recognition, based on quantum parametric mode sorting and single-photon detection. By measuring a photon’s time of flight at picosecond resolution, 97.8% recognition is demonstrated by illuminating only a single point on the materials. Thanks to the exceptional detection sensitivity and noise rejection, a high recognition accuracy of 96.1% is achieved even when the materials are occluded by a lossy and multiscattering obscurant.
Optics Express, 2021
Non-invasive optical imaging through opaque and multi-scattering media remains highly desirable a... more Non-invasive optical imaging through opaque and multi-scattering media remains highly desirable across many application domains. The random scattering and diffusion of light in such media inflict exponential decay and aberration, prohibiting diffraction-limited imaging. By non-interferometric few picoseconds optical gating of backscattered photons, we demonstrate single photon sensitive non-invasive 3D imaging of targets occluded by strongly scattering media with optical thicknesses reaching 9.5ls (19ls round trip). It achieves diffraction-limited imaging of a target placed 130 cm away through the opaque media, with millimeter lateral and depth resolution while requiring only one photon detection out of 50,000 probe pulses. Our single photon sensitive imaging technique does not require wavefront shaping nor computationally-intensive image reconstruction algorithms, promising practical solutions for diffraction-limited imaging through highly opaque and diffusive media with low illumination power.
2019 Conference on Lasers and Electro-Optics (CLEO), 2019
We demonstrate noise-tolerant 3D imaging with 8 dB noise rejection beyond the theoretical limit o... more We demonstrate noise-tolerant 3D imaging with 8 dB noise rejection beyond the theoretical limit of linear-optical matched filters. We perform the imaging from only 0.0006 detected signal photons per pulse despite being swamped by 50-folds stronger background noise. © 2019 The Author(s)
Conference on Lasers and Electro-Optics, 2021
We demonstrated a non-line-of-sight imaging and tracking system with picosecond optical-gated sin... more We demonstrated a non-line-of-sight imaging and tracking system with picosecond optical-gated single photon detection. It sees through obscureness while achiev-ing high resolution NLOS 3D imaging and position retrieval.
Quantum parametric mode sorting has been shown to enable photon counting with precise time gating... more Quantum parametric mode sorting has been shown to enable photon counting with precise time gating and exceptional noise rejection that significantly exceeds what is possible with linear filters. While previous experimental demonstrations were in a collinear optical configuration, its response to off-axis scattering must be understood to apply it more broadly in remote sensing missions. To evaluate this prospect, we use a laboratory testbed to examine its performance for detecting photons at small angles, along both forward and backward directions, after passing through strongly scattering media. Our results find no measurable degradation in detecting noncollinear photons along both directions. This finding indicates that the key intra-pulse coherence essential to quantum parametric mode sorting is maintained at a small scattering angle, permitting its applications on a moving platform.
Non-line-of-sight (NLOS) optical imaging and sensing of objects imply new capabilities valuable t... more Non-line-of-sight (NLOS) optical imaging and sensing of objects imply new capabilities valuable to autonomous technology, machine vision, and other applications. Existing NLOS imaging methods rely heavily on the prowess of computational algorithms to reconstruct the images from weak triply scattered signals. Here, we introduce a new approach to NLOS imaging and sensing using the picosecond gated single photon detection generated by quantum frequency conversion. With exceptional signal isolation, this approach can reliably sense obscured objects around the corner and substantially simplify the data processing needed for position retrieval and surface profiling. For each pixel, only 4×10−3 photons are needed to be detected per pulse to position and profile occluded objects with high resolution. Furthermore, the vibration frequencies of different objects can be resolved by analyzing the photon number fluctuation received within in a ten-picosecond window, allowing NLOS acoustic sensing...
2015 International Conference on Optical Instruments and Technology: Optoelectronic Imaging and Processing Technology, 2015
Microscopy research and technique, 2016
For the design of a passive autofocusing (AF) system for optical microscopes, many time-consuming... more For the design of a passive autofocusing (AF) system for optical microscopes, many time-consuming and tedious experiments have been performed to determine and design a better focus criterion function, owing to the sample-dependence of this function. To accelerate the development of the AF systems in optical microscopes and to increase AF speed as well as maintain the AF accuracy, this study proposes a self-adaptive and nonmechanical motion AF system. The presented AF system does not require the selection and design of a focus criterion function when it is developed. Instead, the system can automatically determine a better focus criterion function for an observed sample by analyzing the texture features of the sample and subsequently perform an AF procedure to bring the sample into focus in the objective of an optical microscope. In addition, to increase the AF speed, the Z axis scanning of the mechanical motion of the sample or the objective is replaced by focusing scanning performe...