1
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Jeong D, Jang H, Jung MU, Jeong T, Kim H, Yang S, Lee J, Kim CS. Spatio-spectral 4D coherent ranging using a flutter-wavelength-swept laser. Nat Commun 2024; 15:1110. [PMID: 38321004 PMCID: PMC10847489 DOI: 10.1038/s41467-024-45297-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 01/18/2024] [Indexed: 02/08/2024] Open
Abstract
Coherent light detection and ranging (LiDAR), particularly the frequency-modulated continuous-wave LiDAR, is a robust optical imaging technology for measuring long-range distance and velocity in three dimensions (3D). We propose a spatio-spectral coherent LiDAR based on a unique wavelength-swept laser to enable both axial coherent ranging and lateral spatio-spectral beam scanning simultaneously. Instead of the conventional unidirectional wavelength-swept laser, a flutter-wavelength-swept laser (FWSL) successfully decoupled bidirectional wavelength modulation and continuous wavelength sweep, which overcame the measurable distance limited by the sampling process. The decoupled operation in FWSL enabled sequential sampling of flutter-wavelength modulation across its wide spectral bandwidth of 160 nm and, thus, allowed simultaneous distance and velocity measurement over an extended measurable distance. Herein, complete four-dimensional (4D) imaging, combining real-time 3D distance and velocity measurements, was implemented by solid-state beam scanning. An acousto-optic scanner was synchronized to facilitate the other lateral beam scanning, resulting in an optimized solid-state coherent LiDAR system. The proposed spatio-spectral coherent LiDAR system achieved high-resolution coherent ranging over long distances and real-time 4D imaging with a frame rate of 10 Hz, even in challenging environments.
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Affiliation(s)
- Dawoon Jeong
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, 46241, Korea
- Engineering Research Center for Color-Modulated Extra-Sensory Perception Technology, Pusan National University, Busan, 46241, Korea
| | - Hansol Jang
- Ground Technology Research Institute, Agency for Defense Development, Daejeon, 34186, Korea
| | - Min Uk Jung
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, 46241, Korea
- Engineering Research Center for Color-Modulated Extra-Sensory Perception Technology, Pusan National University, Busan, 46241, Korea
| | - Taeho Jeong
- Energy Device Research Team, Hyundai Motor Company, Uiwang, Gyeonggi, 16082, Korea
| | - Hyunsoo Kim
- Electromagnetic Energy Materials Research Team, Hyundai Motor Company, Uiwang, Gyeonggi, 16082, Korea
| | - Sanghyeok Yang
- Electromagnetic Energy Materials Research Team, Hyundai Motor Company, Uiwang, Gyeonggi, 16082, Korea
| | - Janghyeon Lee
- Electromagnetic Energy Materials Research Team, Hyundai Motor Company, Uiwang, Gyeonggi, 16082, Korea
| | - Chang-Seok Kim
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, 46241, Korea.
- Engineering Research Center for Color-Modulated Extra-Sensory Perception Technology, Pusan National University, Busan, 46241, Korea.
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2
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Na Y, Kwak H, Ahn C, Lee SE, Lee W, Kang CS, Lee J, Suh J, Yoo H, Kim J. Massively parallel electro-optic sampling of space-encoded optical pulses for ultrafast multi-dimensional imaging. LIGHT, SCIENCE & APPLICATIONS 2023; 12:44. [PMID: 36792590 PMCID: PMC9932157 DOI: 10.1038/s41377-023-01077-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/16/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
High-speed and high-resolution imaging of surface profiles is critical for the investigation of various structures and mechanical dynamics of micro- and nano-scale devices. In particular, recent emergence of various nonlinear, transient and complex mechanical dynamics, such as anharmonic vibrations in mechanical resonators, has necessitated real-time surface deformation imaging with higher axial and lateral resolutions, speed, and dynamic range. However, real-time capturing of fast and complex mechanical dynamics has been challenging, and direct time-domain imaging of displacements and mechanical motions has been a missing element in studying full-field structural and dynamic behaviours. Here, by exploiting the electro-optic sampling with a frequency comb, we demonstrate a line-scan time-of-flight (TOF) camera that can simultaneously measure the TOF changes of more than 1000 spatial coordinates with hundreds megapixels/s pixel-rate and sub-nanometre axial resolution over several millimetres field-of-view. This unique combination of performances enables fast and precise imaging of both complex structures and dynamics in three-dimensional devices and mechanical resonators.
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Affiliation(s)
- Yongjin Na
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Hyunsoo Kwak
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Changmin Ahn
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Seung Eon Lee
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Woojin Lee
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Chu-Shik Kang
- Korea Research Institute of Standards and Science (KRISS), Daejeon, 34113, Korea
| | - Jungchul Lee
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Junho Suh
- Korea Research Institute of Standards and Science (KRISS), Daejeon, 34113, Korea
| | - Hongki Yoo
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Jungwon Kim
- Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea.
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3
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Raji H, Tayyab M, Sui J, Mahmoodi SR, Javanmard M. Biosensors and machine learning for enhanced detection, stratification, and classification of cells: a review. Biomed Microdevices 2022; 24:26. [PMID: 35953679 DOI: 10.1007/s10544-022-00627-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2022] [Indexed: 12/16/2022]
Abstract
Biological cells, by definition, are the basic units which contain the fundamental molecules of life of which all living things are composed. Understanding how they function and differentiating cells from one another, therefore, is of paramount importance for disease diagnostics as well as therapeutics. Sensors focusing on the detection and stratification of cells have gained popularity as technological advancements have allowed for the miniaturization of various components inching us closer to Point-of-Care (POC) solutions with each passing day. Furthermore, Machine Learning has allowed for enhancement in the analytical capabilities of these various biosensing modalities, especially the challenging task of classification of cells into various categories using a data-driven approach rather than physics-driven. In this review, we provide an account of how Machine Learning has been applied explicitly to sensors that detect and classify cells. We also provide a comparison of how different sensing modalities and algorithms affect the classifier accuracy and the dataset size required.
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Affiliation(s)
- Hassan Raji
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ, 08854, USA
| | - Muhammad Tayyab
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ, 08854, USA
| | - Jianye Sui
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ, 08854, USA
| | - Seyed Reza Mahmoodi
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ, 08854, USA
| | - Mehdi Javanmard
- Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ, 08854, USA.
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4
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Xiao S, Davison I, Mertz J. Scan multiplier unit for ultrafast laser scanning beyond the inertia limit. OPTICA 2021; 8:1403-1404. [PMID: 37275678 PMCID: PMC10237152 DOI: 10.1364/optica.445254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 10/09/2021] [Indexed: 06/07/2023]
Abstract
A passive add-on greatly multiplies the sweep rate of any mechanical scanner while also enhancing throughput, enabling a single linear scanner to produce ultrafast 1D or 2D laser scans for general applications.
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Affiliation(s)
- Sheng Xiao
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston MA 02215, USA
| | - Ian Davison
- Department of Biology, Boston University, 24 Cummington Mall, Boston MA 02215, USA
| | - Jerome Mertz
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston MA 02215, USA
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5
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Wang G, Shao L, Liu Y, Xu W, Xiao D, Liu S, Hu J, Zhao F, Shum P, Wang W, Zhou Y, Min R, Wang C. Low-cost compressive sensing imaging based on spectrum-encoded time-stretch structure. OPTICS EXPRESS 2021; 29:14931-14940. [PMID: 33985204 DOI: 10.1364/oe.421055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/17/2021] [Indexed: 06/12/2023]
Abstract
A low-cost compressive sensing imaging (CSI) system based on spectrum-encoded time-stretch (SETS) structure involving cascaded Mach-Zehnder Interferometers (MZIs) for spectral domain random mixing (also known as the optical random pattern generator) is proposed and experimentally demonstrated. A proof-of-principle simulation and experiment is performed. A mode-locked laser with a repetition rate of 50MHz and low-cost cascaded MZIs as the key devices enable fast CSI system. Data compression ratio from 6% to 25% are obtained using proposed CSI based SETS system. The proposed design solves the big data issue in the traditional time-stretch system. It has great potential in fast dynamic phenomena with low-cost and easy-access components.
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6
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Yang Y, Xiang X, Hou F, Quan R, Li B, Li W, Zhu N, Liu T, Zhang S, Dong R, Li M. Inherent resolution limit on nonlocal wavelength-to-time mapping with entangled photon pairs. OPTICS EXPRESS 2020; 28:7488-7497. [PMID: 32225975 DOI: 10.1364/oe.387146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 02/16/2020] [Indexed: 06/10/2023]
Abstract
Nonlocal wavelength-to-time mapping between frequency-entangled photon pairs generated with the process of spontaneous parametric down-conversion is theoretically analyzed and experimentally demonstrated. The spectral filtering pattern experienced by one photon in the photon pair will be non-locally mapped into the time domain when the other photon propagates inside a dispersion-compensation fiber with large group velocity dispersion. Our work, for the first time, points out that the spectral bandwidth of the pump laser will become the dominated factor preventing the improvement of the spectral resolution when the involved group velocity dispersion is large enough, which provides an excellent tool for characterizing the resolution of a nonlocal wavelength-to-time mapping for further quantum information applications.
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7
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Photonic Time-Stretch Technology with Prismatic Pulse Dispersion towards Fast Real-Time Measurements. PHOTONICS 2019. [DOI: 10.3390/photonics6030099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Photonic time-stretch (PTS) technology enables revolutionary technical breakthroughs in ultrafast electronic and optical systems. By means of employing large chromatic dispersion to map the spectrum of an ultrashort optical pulse into a stretched time-domain waveform (namely, using the dispersive Fourier transformation), PTS overcomes the fundamental speed limitations of conventional techniques. The chromatic dispersion utilized in PTS can be implemented using multiple optical prism arrays, which have the particular advantages of low loss in the extended spectrum outside of the specific telecommunication band, flexibility, and cost-effectiveness. In this article, we propose and demonstrate the PTS technology established for a pair of prisms, which works as a data acquisition approach in ultrafast digitizing, imaging, and measurement regimes.
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8
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Li Y, Mahjoubfar A, Chen CL, Niazi KR, Pei L, Jalali B. Deep Cytometry: Deep learning with Real-time Inference in Cell Sorting and Flow Cytometry. Sci Rep 2019; 9:11088. [PMID: 31366998 PMCID: PMC6668572 DOI: 10.1038/s41598-019-47193-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 07/09/2019] [Indexed: 01/22/2023] Open
Abstract
Deep learning has achieved spectacular performance in image and speech recognition and synthesis. It outperforms other machine learning algorithms in problems where large amounts of data are available. In the area of measurement technology, instruments based on the photonic time stretch have established record real-time measurement throughput in spectroscopy, optical coherence tomography, and imaging flow cytometry. These extreme-throughput instruments generate approximately 1 Tbit/s of continuous measurement data and have led to the discovery of rare phenomena in nonlinear and complex systems as well as new types of biomedical instruments. Owing to the abundance of data they generate, time-stretch instruments are a natural fit to deep learning classification. Previously we had shown that high-throughput label-free cell classification with high accuracy can be achieved through a combination of time-stretch microscopy, image processing and feature extraction, followed by deep learning for finding cancer cells in the blood. Such a technology holds promise for early detection of primary cancer or metastasis. Here we describe a new deep learning pipeline, which entirely avoids the slow and computationally costly signal processing and feature extraction steps by a convolutional neural network that directly operates on the measured signals. The improvement in computational efficiency enables low-latency inference and makes this pipeline suitable for cell sorting via deep learning. Our neural network takes less than a few milliseconds to classify the cells, fast enough to provide a decision to a cell sorter for real-time separation of individual target cells. We demonstrate the applicability of our new method in the classification of OT-II white blood cells and SW-480 epithelial cancer cells with more than 95% accuracy in a label-free fashion.
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Affiliation(s)
- Yueqin Li
- Department of Electrical & Computer Engineering, University of California, Los Angeles, California, 90095, USA.,California NanoSystems Institute, Los Angeles, California, 90095, USA.,Key Lab of All Optical Network & Advanced Telecommunication Network, Ministry of Education, Institute of Lightwave Technology, Beijing Jiaotong University, Beijing, 100044, China
| | - Ata Mahjoubfar
- Department of Electrical & Computer Engineering, University of California, Los Angeles, California, 90095, USA.,California NanoSystems Institute, Los Angeles, California, 90095, USA
| | - Claire Lifan Chen
- Department of Electrical & Computer Engineering, University of California, Los Angeles, California, 90095, USA.,California NanoSystems Institute, Los Angeles, California, 90095, USA
| | - Kayvan Reza Niazi
- California NanoSystems Institute, Los Angeles, California, 90095, USA.,NantWorks, LLC, Culver City, California, 90232, USA.,Department of Bioengineering, University of California, Los Angeles, California, 90095, USA
| | - Li Pei
- Key Lab of All Optical Network & Advanced Telecommunication Network, Ministry of Education, Institute of Lightwave Technology, Beijing Jiaotong University, Beijing, 100044, China
| | - Bahram Jalali
- Department of Electrical & Computer Engineering, University of California, Los Angeles, California, 90095, USA. .,California NanoSystems Institute, Los Angeles, California, 90095, USA. .,Department of Bioengineering, University of California, Los Angeles, California, 90095, USA. .,Department of Surgery, UCLA Geffen School of Medicine, Los Angeles, USA.
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9
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Tan S, Wei X, Li B, Lai QTK, Tsia KK, Wong KKY. Ultrafast optical imaging at 2.0 μm through second-harmonic-generation-based time-stretch at 1.0 μm. OPTICS LETTERS 2018; 43:3822-3825. [PMID: 30106892 DOI: 10.1364/ol.43.003822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/13/2018] [Indexed: 06/08/2023]
Abstract
The performance of ultrafast time-stretch imaging at long wavelengths (beyond 1.5 μm) has suffered from low detection sensitivity due to the increasing loss of optical dispersive fibers. Here, we report an ultrafast optical imaging system with a line scan rate of ∼19 MHz at the 2.0-μm wavelength window by combining second-harmonic generation (SHG) with the highly sensitive time-stretch detection at 1.0 μm. In this imaging system, the sample is illuminated by the pulsed laser source at 2.0 μm in the spectrally encoding manner. After SHG, the encoded spectral signal at 2.0 μm is converted to 1.0 μm and then mapped to the time domain through a highly dispersive fiber at 1.0 μm, which provides a superior dispersion-to-loss ratio of ∼53 ps/nm/dB, ∼50 times larger than that of the standard fibers at 2.0 μm (typically ∼1.1 ps/nm/dB). These efforts make it possible for time-stretch technology not only being translated to longer wavelengths, where unique optical absorption contrast exists, but also benefitting from the high detection sensitivity at shorter wavelengths.
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10
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Wang G, Yan Z, Yang L, Zhang L, Wang C. Improved Resolution Optical Time Stretch Imaging Based on High Efficiency In-Fiber Diffraction. Sci Rep 2018; 8:600. [PMID: 29330438 PMCID: PMC5766570 DOI: 10.1038/s41598-017-18920-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/19/2017] [Indexed: 11/10/2022] Open
Abstract
Most overlooked challenges in ultrafast optical time stretch imaging (OTSI) are sacrificed spatial resolution and higher optical loss. These challenges are originated from optical diffraction devices used in OTSI, which encode image into spectra of ultrashort optical pulses. Conventional free-space diffraction gratings, as widely used in existing OTSI systems, suffer from several inherent drawbacks: limited diffraction efficiency in a non-Littrow configuration due to inherent zeroth-order reflection, high coupling loss between free-space gratings and optical fibers, bulky footprint, and more importantly, sacrificed imaging resolution due to non-full-aperture illumination for individual wavelengths. Here we report resolution-improved and diffraction-efficient OTSI using in-fiber diffraction for the first time to our knowledge. The key to overcome the existing challenges is a 45° tilted fiber grating (TFG), which serves as a compact in-fiber diffraction device offering improved diffraction efficiency (up to 97%), inherent compatibility with optical fibers, and improved imaging resolution owning to almost full-aperture illumination for all illumination wavelengths. 50 million frames per second imaging of fast moving object at 46 m/s with improved imaging resolution has been demonstrated. This conceptually new in-fiber diffraction design opens the way towards cost-effective, compact and high-resolution OTSI systems for image-based high-throughput detection and measurement.
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Affiliation(s)
- Guoqing Wang
- School of Engineering and Digital Arts, University of Kent, Canterbury, United Kingdom, CT2 7NT
| | - Zhijun Yan
- School of Optical and Electronic Information (SOEI), Next Generation Internet Access National Engineering Laboratory (NGIAS), Huazhong University of Science and Technology, Wuhan, 430074, China.,Aston Institute of Photonic Technologies, Aston University, Birmingham, United Kingdom, B4 7ET
| | - Lei Yang
- School of Engineering and Digital Arts, University of Kent, Canterbury, United Kingdom, CT2 7NT.,College of Precision Instrument and Optoelectronic Engineering, Tianjin University, Tianjin, 300072, China
| | - Lin Zhang
- Aston Institute of Photonic Technologies, Aston University, Birmingham, United Kingdom, B4 7ET
| | - Chao Wang
- School of Engineering and Digital Arts, University of Kent, Canterbury, United Kingdom, CT2 7NT.
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11
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Kobayashi H, Lei C, Wu Y, Mao A, Jiang Y, Guo B, Ozeki Y, Goda K. Label-free detection of cellular drug responses by high-throughput bright-field imaging and machine learning. Sci Rep 2017. [PMID: 28963483 DOI: 10.1038/s41598‐017‐12378‐4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In the last decade, high-content screening based on multivariate single-cell imaging has been proven effective in drug discovery to evaluate drug-induced phenotypic variations. Unfortunately, this method inherently requires fluorescent labeling which has several drawbacks. Here we present a label-free method for evaluating cellular drug responses only by high-throughput bright-field imaging with the aid of machine learning algorithms. Specifically, we performed high-throughput bright-field imaging of numerous drug-treated and -untreated cells (N = ~240,000) by optofluidic time-stretch microscopy with high throughput up to 10,000 cells/s and applied machine learning to the cell images to identify their morphological variations which are too subtle for human eyes to detect. Consequently, we achieved a high accuracy of 92% in distinguishing drug-treated and -untreated cells without the need for labeling. Furthermore, we also demonstrated that dose-dependent, drug-induced morphological change from different experiments can be inferred from the classification accuracy of a single classification model. Our work lays the groundwork for label-free drug screening in pharmaceutical science and industry.
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Affiliation(s)
| | - Cheng Lei
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan.
| | - Yi Wu
- Department of Computational Biology, Carnegie Mellon University, Pittsburgh, Pennsylvania, 15213, USA
| | - Ailin Mao
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Yiyue Jiang
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Baoshan Guo
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Yasuyuki Ozeki
- Department of Electrical Engineering and Information Systems, University of Tokyo, Tokyo, 113-8656, Japan
| | - Keisuke Goda
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan. .,Japan Science and Technology Agency, Kawaguchi, 332-0012, Japan. .,Department of Electrical Engineering, University of California, Los Angeles, California, 90095, USA.
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12
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Kobayashi H, Lei C, Wu Y, Mao A, Jiang Y, Guo B, Ozeki Y, Goda K. Label-free detection of cellular drug responses by high-throughput bright-field imaging and machine learning. Sci Rep 2017; 7:12454. [PMID: 28963483 PMCID: PMC5622112 DOI: 10.1038/s41598-017-12378-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 09/07/2017] [Indexed: 12/25/2022] Open
Abstract
In the last decade, high-content screening based on multivariate single-cell imaging has been proven effective in drug discovery to evaluate drug-induced phenotypic variations. Unfortunately, this method inherently requires fluorescent labeling which has several drawbacks. Here we present a label-free method for evaluating cellular drug responses only by high-throughput bright-field imaging with the aid of machine learning algorithms. Specifically, we performed high-throughput bright-field imaging of numerous drug-treated and -untreated cells (N = ~240,000) by optofluidic time-stretch microscopy with high throughput up to 10,000 cells/s and applied machine learning to the cell images to identify their morphological variations which are too subtle for human eyes to detect. Consequently, we achieved a high accuracy of 92% in distinguishing drug-treated and -untreated cells without the need for labeling. Furthermore, we also demonstrated that dose-dependent, drug-induced morphological change from different experiments can be inferred from the classification accuracy of a single classification model. Our work lays the groundwork for label-free drug screening in pharmaceutical science and industry.
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Affiliation(s)
| | - Cheng Lei
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan.
| | - Yi Wu
- Department of Computational Biology, Carnegie Mellon University, Pittsburgh, Pennsylvania, 15213, USA
| | - Ailin Mao
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Yiyue Jiang
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Baoshan Guo
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Yasuyuki Ozeki
- Department of Electrical Engineering and Information Systems, University of Tokyo, Tokyo, 113-8656, Japan
| | - Keisuke Goda
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan. .,Japan Science and Technology Agency, Kawaguchi, 332-0012, Japan. .,Department of Electrical Engineering, University of California, Los Angeles, California, 90095, USA.
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13
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Kim C, Mahjoubfar A, Chan JCK, Yazaki A, Noh YC, Jalali B. Matrix Analysis of Warped Stretch Imaging. Sci Rep 2017; 7:11150. [PMID: 28894142 PMCID: PMC5593985 DOI: 10.1038/s41598-017-11238-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 08/21/2017] [Indexed: 11/16/2022] Open
Abstract
Sensitive and fast optical imaging is needed for scientific instruments, machine vision, and biomedical diagnostics. Many of the fundamental challenges are addressed with time stretch imaging, which has been used for ultrafast continuous imaging for a diverse range of applications, such as biomarker-free cell classification, the monitoring of laser ablation, and the inspection of flat panel displays. With frame rates exceeding a million scans per second, the firehose of data generated by the time stretch camera requires optical data compression. Warped stretch imaging technology utilizes nonuniform spectrotemporal optical operations to compress the image in a single-shot real-time fashion. Here, we present a matrix analysis method for the evaluation of these systems and quantify important design parameters and the spatial resolution. The key principles of the system include (1) time/warped stretch transformation and (2) the spatial dispersion of ultrashort optical pulse, which are traced with simple computation of ray-pulse matrix. Furthermore, a mathematical model is constructed for the simulation of imaging operations while considering the optical and electrical response of the system. The proposed analysis method was applied to an example time stretch imaging system via simulation and validated with experimental data.
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Affiliation(s)
- Chanju Kim
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Republic of Korea.
| | - Ata Mahjoubfar
- Department of Electrical Engineering, University of California, Los Angeles, California, 90095, USA.,California NanoSystems Institute, Los Angeles, California, 90095, USA
| | - Jacky C K Chan
- Department of Electrical Engineering, University of California, Los Angeles, California, 90095, USA
| | - Akio Yazaki
- Yokohama Research Laboratory, Hitachi, Ltd., Kanagawa, 244-0817, Japan
| | - Young-Chul Noh
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Republic of Korea
| | - Bahram Jalali
- Department of Electrical Engineering, University of California, Los Angeles, California, 90095, USA.,California NanoSystems Institute, Los Angeles, California, 90095, USA.,Department of Bioengineering, University of California, Los Angeles, California, 90095, USA
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14
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Tan S, Yang L, Wei X, Li C, Chen N, Tsia KK, Wong KKY. High-speed wavelength-swept source at 2.0 μm and its application in imaging through a scattering medium. OPTICS LETTERS 2017; 42:1540-1543. [PMID: 28409792 DOI: 10.1364/ol.42.001540] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report a high-speed wavelength-swept source operating at 2.0 μm through advanced time-stretch technology. It sweeps over 30 nm at a speed of 3.3×109 nm/s and a repetition rate of ∼19 MHz. To the best of our knowledge, this is the first time that a megahertz-stable swept source has been implemented at such a long wavelength. A wide bandwidth is enabled by a simple mode-locked fiber laser that covers a wavelength range of ∼60 nm. The all-optical wavelength sweeping is realized by a chirped fiber Bragg grating (CFBG), which shows a superior temporal stability and power efficiency, compared with commonly used dispersive fibers, particularly in the 2.0 μm wavelength window. To showcase its specialties, here we employ it to perform high-speed spectrally-encoded microscopy (i.e., time-stretch imaging) through a scattering medium at a line-scan rate of up to ∼19 MHz. Better image quality is achieved, compared with a conventional imaging window at 1.0 μm. It is believed that the potential applications of this new high-speed swept source will benefit the transient diagnosis that requires deep penetration through a scattering medium.
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15
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Kim H, An H, Kim J, Lee S, Park K, Lee S, Hong S, Vazquez-Zuniga LA, Lee SY, Lee B, Jeong Y. Corrugation-assisted metal-coated angled fiber facet for wavelength-dependent off-axis directional beaming. OPTICS EXPRESS 2017; 25:8366-8385. [PMID: 28380950 DOI: 10.1364/oe.25.008366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We propose a fiber-optic-plasmonic hybrid device that is based on a corrugation-assisted metal-coated angled fiber facet (CA-MCAFF) for wavelength-dependent off-axis directional beaming (WODB). The device breaks into two key structures: One is the MCAFF structure, which is a modified Kretschmann configuration implemented onto a fiber platform, thereby being able to generate a unidirectional surface plasmon with dramatically enhanced properties in terms of non-confined diffracted radiation loss and operational bandwidth. The other is the periodic corrugation structure put on the MCAFF, thereby enabling WODB functionality out of the whole structures. The corrugated metal surface out-couples the surface plasmon mode to free-space optical radiation into a direction that varies with the wavelength of the optical radiation with excellent linearity. We perform extensive numerical investigations based on the finite-element-method and analyze the out-coupling efficiency (OCEout) and spectral bandwidth (SBout) of the proposed device for various designs and conditions. We determine the seven structural parameters of the device via taking sequential optimization steps. We deduce two optimal conditions particularly for the fiber-facet angle, in terms of the averaged OCEout or the SBout in the whole visible wavelength range (400 - 700 nm), which eventually leads to OCEout = 30.4% and SBout = 230 nm or to OCEout = 24.5% and SBout = 245 nm, respectively. These results suggest substantial enhancements in both OCEout and SBout, in comparison with the performance properties of a typical nano-slit-based device having a similar type of WODB functionality. The proposed CA-MCAFF is a simple, compact and efficient WODB device that is fully compatible with the state-of-the-art optical fiber technology.
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16
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Wu JL, Xu YQ, Xu JJ, Wei XM, Chan ACS, Tang AHL, Lau AKS, Chung BMF, Cheung Shum H, Lam EY, Wong KKY, Tsia KK. Ultrafast laser-scanning time-stretch imaging at visible wavelengths. LIGHT, SCIENCE & APPLICATIONS 2017; 6:e16196. [PMID: 30167195 PMCID: PMC6061895 DOI: 10.1038/lsa.2016.196] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 08/04/2016] [Accepted: 08/11/2016] [Indexed: 05/10/2023]
Abstract
Optical time-stretch imaging enables the continuous capture of non-repetitive events in real time at a line-scan rate of tens of MHz-a distinct advantage for the ultrafast dynamics monitoring and high-throughput screening that are widely needed in biological microscopy. However, its potential is limited by the technical challenge of achieving significant pulse stretching (that is, high temporal dispersion) and low optical loss, which are the critical factors influencing imaging quality, in the visible spectrum demanded in many of these applications. We present a new pulse-stretching technique, termed free-space angular-chirp-enhanced delay (FACED), with three distinguishing features absent in the prevailing dispersive-fiber-based implementations: (1) it generates substantial, reconfigurable temporal dispersion in free space (>1 ns nm-1) with low intrinsic loss (<6 dB) at visible wavelengths; (2) its wavelength-invariant pulse-stretching operation introduces a new paradigm in time-stretch imaging, which can now be implemented both with and without spectral encoding; and (3) pulse stretching in FACED inherently provides an ultrafast all-optical laser-beam scanning mechanism at a line-scan rate of tens of MHz. Using FACED, we demonstrate not only ultrafast laser-scanning time-stretch imaging with superior bright-field image quality compared with previous work but also, for the first time, MHz fluorescence and colorized time-stretch microscopy. Our results show that this technique could enable a wider scope of applications in high-speed and high-throughput biological microscopy that were once out of reach.
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Affiliation(s)
- Jiang-Lai Wu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Yi-Qing Xu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Jing-Jiang Xu
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Xiao-Ming Wei
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Antony CS Chan
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Anson HL Tang
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Andy KS Lau
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Bob MF Chung
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Ho Cheung Shum
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Edmund Y Lam
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Kenneth KY Wong
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Kevin K Tsia
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
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17
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Wang G, Wang C, Yan Z, Zhang L. Highly efficient spectrally encoded imaging using a 45° tilted fiber grating. OPTICS LETTERS 2016; 41:2398-2401. [PMID: 27244373 DOI: 10.1364/ol.41.002398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A novel highly efficient, fiber-compatible spectrally encoded imaging (SEI) system using a 45° tilted fiber grating (TFG) is proposed and experimentally demonstrated for the first time, to the best of our knowledge. The TFG serves as an in-fiber lateral diffraction element, eliminating the need for bulky and lossy free-space diffraction gratings in conventional SEI systems. Under proper polarization control, due to the strong tilted reflection, the 45° TFG offers a diffraction efficiency as high as 93.5%. Our new design significantly reduces the volume of the SEI system and improves energy efficiency and system stability. As a proof-of-principle experiment, spectrally encoded imaging of a customer-designed sample (9.6 mm×3.0 mm) using the TFG-based system is demonstrated. The lateral resolution of the SEI system is measured to be 42 μm in our experiment.
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18
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Hu S, Yao J, Liu M, Luo AP, Luo ZC, Xu WC. Gain-guided soliton fiber laser with high-quality rectangle spectrum for ultrafast time-stretch microscopy. OPTICS EXPRESS 2016; 24:10786-10796. [PMID: 27409899 DOI: 10.1364/oe.24.010786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The ultrafast time-stretch microscopy has been proposed to enhance the temporal resolution of a microscopy system. The optical source is a key component for ultrafast time-stretch microscopy system. Herein, we reported on the gain-guided soliton fiber laser with high-quality rectangle spectrum for ultrafast time-stretch microscopy. By virtue of the excellent characteristics of the gain-guided soliton, the output power and the 3-dB bandwidth of the stable mode-locked soliton could be up to 3 mW and 33.7 nm with a high-quality rectangle shape, respectively. With the proposed robust optical source, the ultrafast time-stretch microscopy with the 49.6 μm resolution and a scan rate of 11 MHz was achieved without the external optical amplification. The obtained results demonstrated that the gain-guided soliton fiber laser could be used as an alternative high-quality optical source for ultrafast time-stretch microscopy and will introduce some applications in fields such as biology, chemical, and optical sensing.
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19
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Lau AKS, Shum HC, Wong KKY, Tsia KK. Optofluidic time-stretch imaging - an emerging tool for high-throughput imaging flow cytometry. LAB ON A CHIP 2016; 16:1743-56. [PMID: 27099993 DOI: 10.1039/c5lc01458a] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Optical imaging is arguably the most effective tool to visualize living cells with high spatiotemporal resolution and in a nearly noninvasive manner. Driven by this capability, state-of-the-art cellular assay techniques have increasingly been adopting optical imaging for classifying different cell types/stages, and thus dissecting the respective cellular functions. However, it is still a daunting task to image and characterize cell-to-cell variability within an enormous and heterogeneous population - an unmet need in single-cell analysis, which is now widely advocated in modern biology and clinical diagnostics. The challenge stems from the fact that current optical imaging technologies still lack the practical speed and sensitivity for measuring thousands to millions of cells down to the single-cell precision. Adopting the wisdom in high-speed fiber-optics communication, optical time-stretch imaging has emerged as a completely new optical imaging concept which is now proven for ultrahigh-throughput optofluidic single-cell imaging, at least 1-2 orders-of-magnitude higher (up to ∼100 000 cells per second) compared to the existing imaging flow cytometers. It also uniquely enables quantification of intrinsic biophysical markers of individual cells - a largely unexploited class of single-cell signatures that is known to be correlated with the overwhelmingly investigated biochemical markers. With the aim of reaching a wider spectrum of experts specializing in cellular assay developments and applications, this paper highlights the essential basics of optical time-stretch imaging, followed by reviewing the recent developments and applications of optofluidic time-stretch imaging. We will also discuss the current challenges of this technology, in terms of providing new insights in basic biology and enriching the clinical diagnostic toolsets.
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Affiliation(s)
- Andy K S Lau
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China.
| | - Ho Cheung Shum
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China
| | - Kenneth K Y Wong
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China.
| | - Kevin K Tsia
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, China.
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20
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Dai B, Zhuo R, Yin S, Lv M, Hong R, Wang Q, Zhang D, Wang X. Ultrafast imaging with anti-aliasing based on optical time-division multiplexing. OPTICS LETTERS 2016; 41:882-885. [PMID: 26974070 DOI: 10.1364/ol.41.000882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Serial time-encoded amplified microscopy (STEAM) is a novel ultrafast imaging technique that is based on space-to-time-to-wavelength mapping. Nevertheless, the technique requires a high-cost electronic digitizer of several tens of gigahertz sampling rate to read out sufficient image information. To acquire a large amount of image information by using a relatively low-sampling-rate electronic digitizer, an anti-aliasing technique based on optical time-division multiplexing is proposed. A 38.88 MHz line-scan imaging system is demonstrated experimentally. By using the proposed anti-aliasing technique, a 20 GS/s sampling rate is achieved by employing a 10 GS/s electronic digitizer. Defects and scratches on the target that were not identifiable originally can be clearly distinguished after using the proposed technique. Numerical analysis shows that the image quality can be improved by 4.16 dB, compared to that not using the anti-aliasing technique and at least 2.3 dB comparing to those obtained by bilinear, bicubic, and nearest-neighbor interpolation and Lanczos resampling techniques.
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21
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Wei X, Lau AKS, Xu Y, Tsia KK, Wong KKY. 28 MHz swept source at 1.0 μm for ultrafast quantitative phase imaging. BIOMEDICAL OPTICS EXPRESS 2015; 6:3855-64. [PMID: 26504636 PMCID: PMC4605045 DOI: 10.1364/boe.6.003855] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/18/2015] [Accepted: 08/31/2015] [Indexed: 05/04/2023]
Abstract
Emerging high-throughput optical imaging modalities, in particular those providing phase information, necessitate a demanding speed regime (e.g. megahertz sweep rate) for those conventional swept sources; while an effective solution is yet to be demonstrated. We demonstrate a stable breathing laser as inertia-free swept source (BLISS) operating at a wavelength sweep rate of 28 MHz, particularly for the ultrafast interferometric imaging modality at 1.0 μm. Leveraging a tunable dispersion compensation element inside the laser cavity, the wavelength sweep range of BLISS can be tuned from ~10 nm to ~63 nm. It exhibits a good intensity stability, which is quantified by the ratio of standard deviation to the mean of the pulse intensity, i.e. 1.6%. Its excellent wavelength repeatability, <0.05% per sweep, enables the single-shot imaging at an ultrafast line-scan rate without averaging. To showcase its potential applications, it is applied to the ultrafast (28-MHz line-scan rate) interferometric time-stretch (iTS) microscope to provide quantitative morphological information on a biological specimen at a lateral resolution of 1.2 μm. This fiber-based inertia-free swept source is demonstrated to be robust and broadband, and can be applied to other established imaging modalities, such as optical coherence tomography (OCT), of which an axial resolution better than 12 μm can be achieved.
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22
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Chen CL, Mahjoubfar A, Jalali B. Optical data compression in time stretch imaging. PLoS One 2015; 10:e0125106. [PMID: 25906244 PMCID: PMC4408077 DOI: 10.1371/journal.pone.0125106] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/20/2015] [Indexed: 01/23/2023] Open
Abstract
Time stretch imaging offers real-time image acquisition at millions of frames per second and subnanosecond shutter speed, and has enabled detection of rare cancer cells in blood with record throughput and specificity. An unintended consequence of high throughput image acquisition is the massive amount of digital data generated by the instrument. Here we report the first experimental demonstration of real-time optical image compression applied to time stretch imaging. By exploiting the sparsity of the image, we reduce the number of samples and the amount of data generated by the time stretch camera in our proof-of-concept experiments by about three times. Optical data compression addresses the big data predicament in such systems.
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Affiliation(s)
- Claire Lifan Chen
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California, United States of America
- California NanoSystems Institute, Los Angeles, California, United States of America
- * E-mail:
| | - Ata Mahjoubfar
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California, United States of America
- California NanoSystems Institute, Los Angeles, California, United States of America
| | - Bahram Jalali
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California, United States of America
- California NanoSystems Institute, Los Angeles, California, United States of America
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, United States of America
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23
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Dispersive Fourier Transformation for Versatile Microwave Photonics Applications. PHOTONICS 2014. [DOI: 10.3390/photonics1040586] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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24
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Metz P, Adam J, Gerken M, Jalali B. Compact, transmissive two-dimensional spatial disperser design with application in simultaneous endoscopic imaging and laser microsurgery. APPLIED OPTICS 2014; 53:376-382. [PMID: 24514122 DOI: 10.1364/ao.53.000376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 12/08/2013] [Indexed: 06/03/2023]
Abstract
Minimally invasive surgery procedures benefit from a reduced size of endoscopic devices. A prospective path to implement miniaturized endoscopy is single optical-fiber-based spectrally encoded imaging. While simultaneous spectrally encoded inertial-scan-free imaging and laser microsurgery have been successfully demonstrated in a large table setup, a highly miniaturized optical design would promote the development of multipurpose endoscope heads. This paper presents a highly scalable, entirely transmissive axial design for a spectral 2D spatial disperser. The proposed design employs a grating prism and a virtual imaged phased array (VIPA). Based on semi-analytical device modeling, we performed a systematic parameter analysis to assess the spectral disperser's manufacturability and to obtain an optimum application-specific design. We found that, in particular, a low grating period combined with a high optical input bandwidth and low VIPA tilt showed favorable results in terms of a high spatial resolution, a small device diameter, and a large field of view. Our calculations reveal that a reasonable imaging performance can be achieved with system diameters of below 5 mm, which renders the proposed 2D spatial disperser design highly suitable for use in future endoscope heads that combine mechanical-scan-free imaging and laser microsurgery.
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25
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Lau AKS, Wong TTW, Ho KKY, Tang MTH, Chan ACS, Wei X, Lam EY, Shum HC, Wong KKY, Tsia KK. Interferometric time-stretch microscopy for ultrafast quantitative cellular and tissue imaging at 1 μm. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:76001. [PMID: 24983913 DOI: 10.1117/1.jbo.19.7.076001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 05/29/2014] [Indexed: 05/20/2023]
Abstract
Quantitative phase imaging (QPI) has been proven to be a powerful tool for label-free characterization of biological specimens. However, the imaging speed, largely limited by the image sensor technology, impedes its utility in applications where high-throughput screening and efficient big-data analysis are mandated. We here demonstrate interferometric time-stretch (iTS) microscopy for delivering ultrafast quantitative phase cellular and tissue imaging at an imaging line-scan rate >20 MHz—orders-of-magnitude faster than conventional QPI. Enabling an efficient time-stretch operation in the 1-μm wavelength window, we present an iTS microscope system for practical ultrafast QPI of fixed cells and tissue sections, as well as ultrafast flowing cells (at a flow speed of up to 8 m∕s). To the best of our knowledge, this is the first time that time-stretch imaging could reveal quantitative morphological information of cells and tissues with nanometer precision. As many parameters can be further extracted from the phase and can serve as the intrinsic biomarkers for disease diagnosis, iTS microscopy could find its niche in high-throughput and high-content cellular assays (e.g., imaging flow cytometry) as well as tissue refractometric imaging (e.g., whole-slide imaging for digital pathology).
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Affiliation(s)
- Andy K S Lau
- University of Hong Kong, Faculty of Engineering, Department of Electrical and Electronic Engineering, Pokfulam Road, Hong Kong, China
| | - Terence T W Wong
- University of Hong Kong, Faculty of Engineering, Department of Electrical and Electronic Engineering, Pokfulam Road, Hong Kong, China
| | - Kenneth K Y Ho
- University of Hong Kong, Faculty of Engineering, Department of Mechanical Engineering, Pokfulam Road, Hong Kong, China
| | - Matthew T H Tang
- University of Hong Kong, Faculty of Engineering, Department of Mechanical Engineering, Pokfulam Road, Hong Kong, China
| | - Antony C S Chan
- University of Hong Kong, Faculty of Engineering, Department of Electrical and Electronic Engineering, Pokfulam Road, Hong Kong, China
| | - Xiaoming Wei
- University of Hong Kong, Faculty of Engineering, Department of Electrical and Electronic Engineering, Pokfulam Road, Hong Kong, China
| | - Edmund Y Lam
- University of Hong Kong, Faculty of Engineering, Department of Electrical and Electronic Engineering, Pokfulam Road, Hong Kong, China
| | - Ho Cheung Shum
- University of Hong Kong, Faculty of Engineering, Department of Mechanical Engineering, Pokfulam Road, Hong Kong, ChinacUniversity of Hong Kong-Shenzhen Institute of Research and Innovation, Shenzhen Software Park, Shenzhen, China
| | - Kenneth K Y Wong
- University of Hong Kong, Faculty of Engineering, Department of Electrical and Electronic Engineering, Pokfulam Road, Hong Kong, China
| | - Kevin K Tsia
- University of Hong Kong, Faculty of Engineering, Department of Electrical and Electronic Engineering, Pokfulam Road, Hong Kong, China
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26
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Adam J, Mahjoubfar A, Diebold ED, Buckley BW, Jalali B. Spectrally encoded angular light scattering. OPTICS EXPRESS 2013; 21:28960-28967. [PMID: 24514410 DOI: 10.1364/oe.21.028960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The angular light scattering profile of microscopic particles significantly depends on their morphological parameters, such as size and shape. This dependency is widely used in state-of-the-art flow cytometry methods for particle classification. We introduce a new spectrally encoded angular light scattering method, with potential application in scanning flow cytometry. We show that a one-to-one wavelength-to-angle mapping enables the measurement of the angular dependence of scattered light from microscopic particles over a wide dynamic range. Improvement in dynamic range is obtained by equalizing the angular dependence of scattering via wavelength equalization. Continuous angular spectrum is obtained without mechanical scanning enabling single-shot measurement. Using this information, particle morphology can be determined with improved accuracy. We derive and experimentally verify an analytic wavelength-to-angle mapping model, facilitating rapid data processing. As a proof of concept, we demonstrate the method's capability of distinguishing differently sized polystyrene beads. The combination of this technique with time-stretch dispersive Fourier transform offers real-time and high-throughput (high frame rate) measurements and renders the method suitable for integration in standard flow cytometers.
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27
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Xing F, Chen H, Chen M, Yang S, Xie S. Simple approach for fast real-time line scan microscopic imaging. APPLIED OPTICS 2013; 52:7049-7053. [PMID: 24085222 DOI: 10.1364/ao.52.007049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/11/2013] [Indexed: 06/02/2023]
Abstract
A simple fast line scan microscopic imaging approach based on a wavelength-space-time mapping technique has been proposed. With a lab-made subpicosecond pulse laser with 10 dB bandwidth of 12 nm, we experimentally demonstrate a free-space optical apparatus designed for fast line scan imaging of microscopic objects. This system has a spatial resolution of 22 μm, field-of-view of 2.5 mm, and line scan rate of 20.9 MHz. By imaging a modified unitraveling carrier photodetector, we demonstrate the application of semiconductor device inspection for speeding up quality control.
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28
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Mahjoubfar A, Goda K, Betts G, Jalali B. Optically amplified detection for biomedical sensing and imaging. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2013; 30:2124-2132. [PMID: 24322867 DOI: 10.1364/josaa.30.002124] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Optical sensing and imaging methods for biomedical applications, such as spectroscopy and laser-scanning fluorescence microscopy, are incapable of performing sensitive detection at high scan rates due to the fundamental trade-off between sensitivity and speed. This is because fewer photons are detected during short integration times and hence the signal falls below the detector noise. Optical postamplification can, however, overcome this challenge by amplifying the collected optical signal after collection and before photodetection. Here we present a theoretical analysis of the sensitivity of high-speed biomedical sensing and imaging systems enhanced by optical postamplifiers. As a case study, we focus on Raman amplifiers because they produce gain at any wavelength within the gain medium's transparency window and are hence suitable for biomedical applications. Our analytical model shows that when limited by detector noise, such optically postamplified systems can achieve a sensitivity improvement of up to 20 dB in the visible to near-infrared spectral range without sacrificing speed. This analysis is expected to be valuable for design of fast real-time biomedical sensing and imaging systems.
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29
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Ilgayev O, Yelin D. Phase-sensitive imaging of tissue acoustic vibrations using spectrally encoded interferometry. OPTICS EXPRESS 2013; 21:19681-9. [PMID: 24105515 DOI: 10.1364/oe.21.019681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Acoustic vibrations in tissue are often difficult to image, requiring high-speed scanning, high sensitivity and nanometer-scale axial resolution. Here we use spectrally encoded interferometry to measure the vibration pattern of two-dimensional surfaces, including the skin of a volunteer, at nanometric resolution, without the need for rapid lateral scanning and with no prior knowledge of the driving acoustic waveform. Our results demonstrate the feasibility of this technique for measuring tissue biomechanics using simple and compact imaging probes.
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30
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Chen H, Wang C, Yazaki A, Kim C, Goda K, Jalali B. Ultrafast web inspection with hybrid dispersion laser scanner. APPLIED OPTICS 2013; 52:4072-4076. [PMID: 23759858 DOI: 10.1364/ao.52.004072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 05/15/2013] [Indexed: 06/02/2023]
Abstract
We report an ultrafast web inspector that operates at a 1000 times higher scan rate than conventional methods. This system is based on a hybrid dispersion laser scanner that performs line scans at nearly 100 MHz. Specifically, we demonstrate web inspection with detectable resolution of 48.6 μm/pixel (scan direction) × 23 μm (web flow direction) within a width of view of 6 mm at a record high scan rate of 90.9 MHz. We demonstrate the identification and evaluation of particles on silicon wafers. This method holds great promise for speeding up quality control and hence reducing manufacturing costs.
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Affiliation(s)
- Hongwei Chen
- Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA
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31
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Mahjoubfar A, Chen C, Niazi KR, Rabizadeh S, Jalali B. Label-free high-throughput cell screening in flow. BIOMEDICAL OPTICS EXPRESS 2013; 4:1618-25. [PMID: 24049682 PMCID: PMC3771832 DOI: 10.1364/boe.4.001618] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/24/2013] [Accepted: 08/06/2013] [Indexed: 05/05/2023]
Abstract
Flow cytometry is a powerful tool for cell counting and biomarker detection in biotechnology and medicine especially with regards to blood analysis. Standard flow cytometers perform cell type classification both by estimating size and granularity of cells using forward- and side-scattered light signals and through the collection of emission spectra of fluorescently-labeled cells. However, cell surface labeling as a means of marking cells is often undesirable as many reagents negatively impact cellular viability or provide activating/inhibitory signals, which can alter the behavior of the desired cellular subtypes for downstream applications or analysis. To eliminate the need for labeling, we introduce a label-free imaging-based flow cytometer that measures size and cell protein concentration simultaneously either as a stand-alone instrument or as an add-on to conventional flow cytometers. Cell protein concentration adds a parameter to cell classification, which improves the specificity and sensitivity of flow cytometers without the requirement of cell labeling. This system uses coherent dispersive Fourier transform to perform phase imaging at flow speeds as high as a few meters per second.
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Affiliation(s)
- Ata Mahjoubfar
- Department of Electrical Engineering, University of California, Los Angeles, California 90095 USA
- California NanoSystems Institute, Los Angeles, California 90095 USA
| | - Claire Chen
- Department of Electrical Engineering, University of California, Los Angeles, California 90095 USA
- California NanoSystems Institute, Los Angeles, California 90095 USA
| | - Kayvan R. Niazi
- California NanoSystems Institute, Los Angeles, California 90095 USA
- Department of Bioengineering, University of California, Los Angeles, California 90095 USA
- NantWorks, LLC, Culver City, California 90232 USA
| | - Shahrooz Rabizadeh
- California NanoSystems Institute, Los Angeles, California 90095 USA
- Department of Bioengineering, University of California, Los Angeles, California 90095 USA
- NantWorks, LLC, Culver City, California 90232 USA
| | - Bahram Jalali
- Department of Electrical Engineering, University of California, Los Angeles, California 90095 USA
- California NanoSystems Institute, Los Angeles, California 90095 USA
- Department of Bioengineering, University of California, Los Angeles, California 90095 USA
- Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, California 90095 USA
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