Article
Multidisciplinary Sciences
Saeed Sharif Azadeh, Jason C. C. Mak, Hong Chen, Xianshu Luo, Fu-Der Chen, Hongyao Chua, Frank Weiss, Christopher Alexiev, Andrei Stalmashonak, Youngho Jung, John N. Straguzzi, Guo-Qiang Lo, Wesley D. Sacher, Joyce K. S. Poon
Summary: Laser beam scanning is crucial in many applications and the miniaturization of scanners into microchips has driven the development of photonic integrated circuits. However, achieving a compact size, broad wavelength operation, and low power consumption remains a challenge. In this study, we present a laser beam scanner that meets these requirements using microcantilevers embedded with silicon nitride nanophotonic circuitry. These microcantilevers demonstrate broadband, one- and two-dimensional steering of light with a wide range of wavelengths. The microcantilevers have a small area, consume low power, are easy to control, and emit a single light beam. They are integrated on silicon wafers, enabling versatile, power-efficient, and broadband laser scanner microchips.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Hong-Jib Yoon, Byung-Wook Min
Summary: This paper presents a fast far-field phased array calibration/beamforming method using an improved version of the REV method. Experimentally verified, the improved method reduces the number of required measurements and enhances the accuracy and efficiency of the calibration process.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Multidisciplinary Sciences
T. Mizuno, E. Hase, T. Minamikawa, Y. Tokizane, R. Oe, H. Koresawa, H. Yamamoto, T. Yasui
Summary: This study demonstrates scan-less full-field FLIM based on frequency-multiplexed RF signals, allowing for rapid acquisition of bimodal images of fluorescence amplitude and lifetime without the need for mechanical scanning. This technique has the potential to be useful for quantitative fluorescence imaging in life science.
Article
Optics
Bibek R. Samanta, Flavio Pardo, Todd Salamon, Rose Kopf, Michael S. Eggleston
Summary: This paper presents an electrothermally actuated MEMS mirror capable of reliable linear raster scanning with a large angular range of motion. A simple pulse design technique and segmented polysilicon microheaters are used to achieve high-speed scanning and low power consumption.
Article
Optics
Ying Tian, Huotao Gao, Wang Yao, Jiong Wu, Linyan Guo
Summary: This paper proposes antenna elements with low profile and high front-to-back (FB) ratio, achieved by attaching broadband polarization conversion metasurfaces (PCMs) as parasitic patches. The array formed by these elements is arranged in a checkerboard form, resulting in lower radar cross section (RCS) in X- and Ku- bands. The proposed antenna elements maintain a small size even with PCMs loaded, enabling beam scanning and suitability for phased array.
Article
Optics
Zihan Zang, Zhi Li, Yi Luo, Yanjun Han, Hongtao Li, Xuanyi Liu, H. Y. Fu
Summary: This study combines all-optical encoders with wavelength-division multiplexing devices to achieve fast and efficient acquisition of light detection and ranging (LiDAR) technology. By implementing parallel detection and fast spectral scanning, the fastest single-pixel LiDAR to date is achieved, with scalability to increase detection speed. This approach breaks the limitations of current ultrafast single-pixel LiDAR and opens up new possibilities for ultrafast-frame-rate imaging systems.
Article
Optics
Mathias Prost, Jon Oyvind Kjellman, Sarvagya Dwivedi, Aleksandrs Marinins, Hemant Kumar Tyagi, Tangla David Kongnyuy, Philippe Soussan, Marcus S. Dahlem, Xavier Rottenberg, Roelof Jansen
Summary: This paper demonstrates an on-chip integrated phase calibration system for optical phased arrays (OPAs), which includes compact phase interrogator structures and readout photodiodes. The calibration enables high-fidelity beam steering and arbitrary pattern generation.
Article
Optics
Guang Zhu Zhou, Bao-jie Chen, Geng-bo Wu, Shi-wei Qu, Chi Hou Chan
Summary: This study reports a plasmonic optical leaky-wave antenna with low sidelobe level (SLL). By modulating the electric-field amplitude, the antenna achieves the conversion between guided waves and free-space waves, and reduces the SLL by controlling the aperture field. Experimental results demonstrate high directivity and low SLL, and the antenna allows for arbitrary wavefront shaping.
PHOTONICS RESEARCH
(2023)
Article
Physics, Applied
Kim Robert Tekseth, Jonas Rudshaug, Mahdieh Gholami Mayani, Muhammad Nadeem Akram, Tore Borvik, Dag Werner Breiby
Summary: Glass is increasingly used as a load-carrying construction material, making the investigation of its mechanical properties and surface defects crucial. This study demonstrates the use of Fourier ptychographic microscopy to detect and measure glass surface defects through quantitative phase images. The proposed technique allows for quantitative and scalable defect analysis over extended areas, which can contribute to better mechanical models for predicting glass failure.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Wenchang Lai, Guozhong Lei, Qi Meng, Yanxing Ma, Wenda Cui, Dongfeng Shi, Hao Liu, Yan Wang, Kai Han
Summary: This article proposes the use of a Fermat spiral laser array as an illumination source in ghost imaging. The array successfully achieves high-quality ghost imaging through experimental demonstration and the combination with a compressive sensing reconstruction algorithm. This method has great potential for application in remote sensing.
Article
Optics
Wenchang Lai, Guozhong Lei, Qi Meng, Yanxing Ma, Wenda Cui, Dongfeng Shi, Hao Liu, Yan Wang, Kai Han
Summary: A novel laser array is proposed as an illumination source for ghost imaging. Experimental demonstration shows that the method can achieve high-quality ghost imaging. This technology is expected to be applied in the field of remote sensing.
Article
Engineering, Multidisciplinary
WenFa Zhu, YanXun Xiang, HaiYan Zhang, Yao Cheng, GuoPeng Fan, Hui Zhang
Summary: Rail damage is a major factor affecting the safe operation of trains, and it is important to accurately detect this damage. In this study, the phased array total focus method (TFM) imaging was applied to rail-damage detection, and a new method called directivity correction-based sparse TFM imaging method (DC-TFM) was proposed to improve the accuracy and computing time of the existing methods. Experimental results showed that the proposed method significantly improved the accuracy and speed of rail-damage detection.
Article
Optics
Thomas Haddad, Carlos Biurrun-Quel, Peng Lu, Jonas Tebart, Benedikt Sievert, Sumer Makhlouf, Marcel Grzeslo, Jorge Teniente, Carlos Del-Rio, Andreas Stoehr
Summary: A novel photonic-assisted 2-D Terahertz beam steering chip using only two tuning elements is proposed, achieving control of both elevation and azimuth beam angles. Theoretical predictions and experimental results show good agreement, with a maximum angle deviation below 5 degrees. Experimental scanning angles are limited by mechanical constraints and on-wafer integration.
Article
Optics
Guangzhu Zhou, Shi-Wei Qu, Baojie Chen, Yuansong Zeng, Chi Hou Chan
Summary: This paper presents a metasurface-based Fourier lens fed by compact plasmonic optical antennas for wide-angle beam steering. The proposed device has a wide beam steering range, good radiation characteristics, small footprint, and ease of integration, making it suitable for various integrated photonics applications.
Article
Physics, Applied
Ryo Tetsuya, Takemasa Tamanuki, Hiroyuki Ito, Hiroshi Abe, Ryo Kurahashi, Miyoshi Seki, Minoru Ohtsuka, Nobuyuki Yokoyama, Makoto Okano, Toshihiko Baba
Summary: Photonic crystal waveguide slow-light grating can emit and steer optical beams, and is used as a beam scanner for light detection and ranging (LiDAR). Dividing the waveguide into multiple antennas in a serial array configuration improves reception performance.
APPLIED PHYSICS LETTERS
(2021)
Article
Neurosciences
Chi Wah Wong, Pamela N. DeYoung, Thomas T. Liu
Article
Neurosciences
Thomas T. Liu
Article
Neurosciences
Alican Nalci, Bhaskar D. Rao, Thomas T. Liu
Reprint
Neurosciences
Thomas T. Liu
Article
Neurosciences
Thomas T. Liu, Alican Nalci, Maryam Falahpour
Article
Psychology, Clinical
Tanya T. Nguyen, Sanja Kovacevic, Sheena I. Dev, Kun Lu, Thomas T. Liu, Lisa T. Eyler
Article
Multidisciplinary Sciences
Qiu Ge, Wei Peng, Jian Zhang, Xuchu Weng, Yong Zhang, Thomas Liu, Yu-Feng Zang, Ze Wang
Article
Neuroimaging
Alexandra L. Clark, Katherine J. Bangen, Scott F. Sorg, Dawn M. Schiehser, Nicole D. Evangelista, Benjamin McKenna, Thomas T. Liu, Lisa Delano-Wood
NEUROIMAGE-CLINICAL
(2017)
Article
Engineering, Electrical & Electronic
Alican Nalci, Igor Fedorov, Maher Al-Shoukairi, Thomas T. Liu, Bhaskar D. Rao
IEEE TRANSACTIONS ON SIGNAL PROCESSING
(2018)
Article
Neurosciences
Maryam Falahpour, Catie Chang, Chi Wah Wong, Thomas T. Liu
Review
Nutrition & Dietetics
Peter J. Joris, Ronald P. Mensink, Tanja C. Adam, Thomas T. Liu
Article
Multidisciplinary Sciences
Juergen Dukart, Stefan Holiga, Christopher Chatham, Peter Hawkins, Anna Forsyth, Rebecca McMillan, Jim Myers, Anne R. Lingford-Hughes, David J. Nutt, Emilio Merlo-Pich, Celine Risterucci, Lauren Boak, Daniel Umbricht, Scott Schobel, Thomas Liu, Mitul A. Mehta, Fernando O. Zelaya, Steve C. Williams, Gregory Brown, Martin Paulus, Garry D. Honey, Suresh Muthukumaraswamy, Joerg Hipp, Alessandro Bertolino, Fabio Sambataro
SCIENTIFIC REPORTS
(2018)
Article
Medicine, Research & Experimental
Thomas T. Liu
WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE
(2020)
Article
Neurosciences
Thomas T. Liu, Bochao Li, Brice Fernandez, Suchandrima Banerjee
Summary: In multi-echo fMRI research, tSNR and dCNR are two important metrics for evaluating performance. The study identified three main patterns of weight dependence for these metrics, namely tSNR-robust regime, dCNR-robust regime, and within-type robust regime.
Article
Health Care Sciences & Services
Chelsea C. Hays Weeks, Alison A. Moore, Matthew Allison, Kevin Patrick, Mark W. Bondi, Camille Nebeker, Thomas Liu, David Wing, Michael Higgins, Sheri J. Hartman, Robert A. Rissman, Zvinka Z. Zlatar
Summary: This study aims to develop an innovative intervention that utilizes mobile health technology to help older adults increase physical activity in free-living environments. By providing real-time feedback, older adults can maintain moderate-to-vigorous physical activity during exercise sessions to reduce the burden of Alzheimer's disease and related dementias and improve quality of life. The importance of this study lies in applying laboratory findings to everyday life and better understanding the impact of moderate-to-vigorous physical activity on brain and cognitive health.
JMIR RESEARCH PROTOCOLS
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Slimane Tounekti, Mahdi Alizadeh, Devon Middleton, James S. Harrop, Bassem Hiba, Laura Krisa, Choukri Mekkaoui, Feroze B. Mohamed
Summary: This study proposes and demonstrates a new method combining reduced field-of-view strategy with phase segmented EPI to address geometric distortion in post-operative DTI scans of patients with metal implants. The results show that the new method outperforms traditional techniques in reducing distortion.
MAGNETIC RESONANCE IMAGING
(2024)
Article
Radiology, Nuclear Medicine & Medical Imaging
Silvia Minosse, Eliseo Picchi, Valentina Ferrazzoli, Noemi Pucci, Valerio Da Ros, Raffaella Giocondo, Roberto Floris, Francesco Garaci, Francesca Di Giuliano
Summary: The aim of this study was to investigate the variation of DCE-MRI-derived kinetic parameters in brain tumors as a function of acquisition time. The results showed that K-ep and V-e were time-dependent and required longer scan times to obtain reliable parameter values, while K-trans was time-independent and remained the same in all acquisition times, making it a reliable parameter for short acquisition times.
MAGNETIC RESONANCE IMAGING
(2024)
Article
Radiology, Nuclear Medicine & Medical Imaging
Xingmin Guan, Xinheng Zhang, Hsin-Jung Yang, Rohan Dharmakumar
Summary: This study aims to investigate why DIR-prepared dark-blood T2* weighted images have lower SNR, CNR, and diagnostic accuracy for intramyocardial hemorrhage (IMH) detection compared to non-DIR-prepared bright-blood T2* images. Through phantom and animal studies, it was confirmed that the signal loss on DIR-prepared T2* images mainly originates from spin-relaxation during the DIR preparation. Therefore, when used for IMH detection, extra attention should be paid to the SNR of DIR-prepared dark-blood T2* imaging protocols.
MAGNETIC RESONANCE IMAGING
(2024)
Article
Radiology, Nuclear Medicine & Medical Imaging
Beatriz Laureano, Hassna Irzan, Helen OReilly, Sebastian Ourselin, Neil Marlow, Andrew Melbourne
Summary: Prematurity and preterm stressors have significant effects on the development of infants, especially at earlier gestations. While neonatal care advances have reduced preterm mortality rates, disability rates continue to grow in middle-income settings. Imaging the preterm brain using MR technology has improved our understanding of its development and the affected regions and networks. This research aims to support interventions, improve neurodevelopment, and provide accurate prognoses for preterm infants. This study focuses on the fully developed brain of extremely preterm subjects and examines myelin-related biomarkers to assess long-term effects. The findings suggest altered connectivity and cognitive outcomes in the adult preterm brain.
MAGNETIC RESONANCE IMAGING
(2024)
Article
Radiology, Nuclear Medicine & Medical Imaging
Julian Rauch, Frederik B. Laun, Peter Bachert, Mark E. Ladd, Tristan A. Kuder
Summary: This study presents a method for reducing concomitant field effects in double diffusion encoding (DDE) sequences by adding oscillating gradient pulses. The modified sequences successfully reduced accumulated concomitant phase without significant changes in the original sequence characteristics. The proposed method led to an increase in signal-to-noise ratio (SNR) for phantom and in vivo experiments, supported by simulations.
MAGNETIC RESONANCE IMAGING
(2024)
Article
Radiology, Nuclear Medicine & Medical Imaging
Marlon Bran Lorenzana, Shekhar S. Chandra, Feng Liu
Summary: Sparse reconstruction is important in MRI for reducing acquisition time and improving spatial-temporal resolution. This paper introduces two decoupling techniques for explicit 1D regularization and a combined 1D + 2D reconstruction technique that improves image quality.
MAGNETIC RESONANCE IMAGING
(2024)
Article
Radiology, Nuclear Medicine & Medical Imaging
Yifan Gou, W. Christopher Golden, Zixuan Lin, Jennifer Shepard, Aylin Tekes, Zhiyi Hu, Xin Li, Kumiko Oishi, Marilyn Albert, Hanzhang Lu, Peiying Liu, Dengrong Jiang
Summary: ARTS algorithm improves the reliability of Y-v estimation in noncompliant subjects, enhancing the utility of Y-v as a biomarker for brain diseases.
MAGNETIC RESONANCE IMAGING
(2024)
