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Zhang Y, Suo J, Wang Y, Dai Q. Doubling the pixel count limitation of single-pixel imaging via sinusoidal amplitude modulation. OPTICS EXPRESS 2018; 26:6929-6942. [PMID: 29609379 DOI: 10.1364/oe.26.006929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/20/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate a single-pixel imaging (SPI) method that can achieve pixel resolution beyond the physical limitation of the spatial light modulator (SLM), by adopting sinusoidal amplitude modulation and frequency filtering. Through light field analysis, we observe that the induced intensity with a squared value of the amplitude contains higher frequency components. By filtering out the zero frequency of the sinusoidal amplitude in the Fourier domain, we can separate out the higher frequency components, which enables SPI with higher resolving ability and thus beyond the limitation of the SLM. Further, to address the speed issue in grayscale spatial light modulation, we propose a fast implementation scheme with tens-of-kilohertz refresh rate. Specifically, we use a digital micromirror device (DMD) working at the full frame rate to conduct binarized sinusoidal patterning in the spatial domain and pinhole filtering eliminating the binarization error in the Fourier domain. For experimental validation, we build a single-pixel microscope to retrieve 1200 × 1200-pixel images via a sub-megapixel DMD, and the setup achieves comparable performance to array sensor microscopy and provides additional sectioning ability.
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Wu J, Tang AHL, Mok ATY, Yan W, Chan GCF, Wong KKY, Tsia KK. Multi-MHz laser-scanning single-cell fluorescence microscopy by spatiotemporally encoded virtual source array. BIOMEDICAL OPTICS EXPRESS 2017; 8:4160-4171. [PMID: 28966855 PMCID: PMC5611931 DOI: 10.1364/boe.8.004160] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/10/2017] [Accepted: 08/15/2017] [Indexed: 05/15/2023]
Abstract
Apart from the spatial resolution enhancement, scaling of temporal resolution, equivalently the imaging throughput, of fluorescence microscopy is of equal importance in advancing cell biology and clinical diagnostics. Yet, this attribute has mostly been overlooked because of the inherent speed limitation of existing imaging strategies. To address the challenge, we employ an all-optical laser-scanning mechanism, enabled by an array of reconfigurable spatiotemporally-encoded virtual sources, to demonstrate ultrafast fluorescence microscopy at line-scan rate as high as 8 MHz. We show that this technique enables high-throughput single-cell microfluidic fluorescence imaging at 75,000 cells/second and high-speed cellular 2D dynamical imaging at 3,000 frames per second, outperforming the state-of-the-art high-speed cameras and the gold-standard laser scanning strategies. Together with its wide compatibility to the existing imaging modalities, this technology could empower new forms of high-throughput and high-speed biological fluorescence microscopy that was once challenged.
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Affiliation(s)
- Jianglai Wu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Anson H. L. Tang
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Aaron T. Y. Mok
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Wenwei Yan
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Godfrey C. F. Chan
- Department of Pediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong Pokfulam Road, Hong Kong, China
| | - Kenneth K. Y. Wong
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Kevin K. Tsia
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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Olsovsky C, Shelton R, Carrasco-Zevallos O, Applegate BE, Maitland KC. Chromatic confocal microscopy for multi-depth imaging of epithelial tissue. BIOMEDICAL OPTICS EXPRESS 2013; 4:732-40. [PMID: 23667789 PMCID: PMC3646600 DOI: 10.1364/boe.4.000732] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/12/2013] [Accepted: 04/15/2013] [Indexed: 05/20/2023]
Abstract
We present a novel chromatic confocal microscope capable of volumetric reflectance imaging of microstructure in non-transparent tissue. Our design takes advantage of the chromatic aberration of aspheric lenses that are otherwise well corrected. Strong chromatic aberration, generated by multiple aspheres, longitudinally disperses supercontinuum light onto the sample. The backscattered light detected with a spectrometer is therefore wavelength encoded and each spectrum corresponds to a line image. This approach obviates the need for traditional axial mechanical scanning techniques that are difficult to implement for endoscopy and susceptible to motion artifact. A wavelength range of 590-775 nm yielded a >150 µm imaging depth with ~3 µm axial resolution. The system was further demonstrated by capturing volumetric images of buccal mucosa. We believe these represent the first microstructural images in non-transparent biological tissue using chromatic confocal microscopy that exhibit long imaging depth while maintaining acceptable resolution for resolving cell morphology. Miniaturization of this optical system could bring enhanced speed and accuracy to endomicroscopic in vivo volumetric imaging of epithelial tissue.
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Bedard N, Tkaczyk TS. Snapshot spectrally encoded fluorescence imaging through a fiber bundle. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:080508-1. [PMID: 23224159 PMCID: PMC3422462 DOI: 10.1117/1.jbo.17.8.080508] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 06/18/2012] [Accepted: 07/18/2012] [Indexed: 05/21/2023]
Abstract
Fiber optic endomicroscopy is a valuable tool for clinical diagnostics and animal studies because it can capture images of tissue in vivo with subcellular resolution. Current configurations for endomicroscopes have either limited spatial resolution or require a scanning mechanism at the distal end of the fiber, which can slow imaging speed and increase the probe size. We present a novel configuration that provides high contrast 350 × 350 pixel images at 7.2 frames per second, without the need for mechanical scanning at the proximal or distal end of the fiber. The proof-of-concept benchtop system is tested in fluorescence mode and can resolve 1.5 µm features of a high resolution 1951 USAF target.
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Affiliation(s)
- Noah Bedard
- Rice University, Department of Bioengineering, 6500 Main Street, MS-142, Houston, Texas 77005
| | - Tomasz S. Tkaczyk
- Rice University, Department of Bioengineering, 6500 Main Street, MS-142, Houston, Texas 77005
- Address all correspondence to: Tomasz S. Tkaczyk, Rice University, Department of Bioengineering, 6500 Main Street, MS-142, Houston, Texas 77005. E-mail:
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Lemire-Renaud S, Strupler M, Benboujja F, Godbout N, Boudoux C. Double-clad fiber with a tapered end for confocal endomicroscopy. BIOMEDICAL OPTICS EXPRESS 2011; 2:2961-72. [PMID: 22076259 PMCID: PMC3207367 DOI: 10.1364/boe.2.002961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/10/2011] [Accepted: 08/25/2011] [Indexed: 05/11/2023]
Abstract
We present a double-clad fiber coupler (DCFC) for use in confocal endomicroscopy to reduce speckle contrast, increase signal collection while preserving optical sectioning. The DCFC is made by incorporating a double-clad tapered fiber (DCTF) to a fused-tapered DCFC for achromatic transmission (from 1265 nm to 1325 nm) of > 95% illumination light trough the single mode (SM) core and collection of > 40% diffuse light through inner cladding modes. Its potential for confocal endomicroscopy is demonstrated in a spectrally-encoded imaging setup which shows a 3 times reduction in speckle contrast as well as 5.5 × increase in signal collection compared to imaging with a SM fiber.
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Affiliation(s)
- Simon Lemire-Renaud
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec,
Canada
- Centre d′Optique, Photonique et Laser, 2375, de la Terrasse Road, Quebec, Quebec,
Canada
| | - Mathias Strupler
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec,
Canada
- Sainte-Justine Mother and Child University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec,
Canada
| | - Fouzi Benboujja
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec,
Canada
- Sainte-Justine Mother and Child University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec,
Canada
| | - Nicolas Godbout
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec,
Canada
- Centre d′Optique, Photonique et Laser, 2375, de la Terrasse Road, Quebec, Quebec,
Canada
| | - Caroline Boudoux
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec,
Canada
- Centre d′Optique, Photonique et Laser, 2375, de la Terrasse Road, Quebec, Quebec,
Canada
- Sainte-Justine Mother and Child University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec,
Canada
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Abstract
Spectral imaging, i.e. the acquisition of the spectrum emitted from each sample location, is a powerful tool for a wide variety of applications in science and technology. For biomedical applications, spectral imaging is important for accurate analysis of a biological specimen and for assisting clinical diagnosis, however it could be challenging mainly due to the typically low damage thresholds and strict time constraints. Here, we present a fiber-based technique termed spectrally encoded spectral imaging (SESI), in which a fully emitted spectrum is captured from each resolvable point of a specimen using an additional lateral scanning of the spectrally encoded line. The technique is demonstrated by capturing spectral data cubes of a color print and of a green leaf, and its potential advantage in signal-to-noise ratio is theoretically discussed. Using a miniaturized grating-lens configuration, SESI could be conducted endoscopically, allowing minimally invasive color and spectral imaging in remote locations of the body.
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Affiliation(s)
- Avraham Abramov
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Technion City, Haifa, Israel
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