Virtual Journal of Biomedical Optics
Full-field optical coherence tomography using nematic liquid-crystal phase shifter
Sheng-Hua Lu, Chien-Yell Wang, Cho-Yen Hsieh, Kuan-Yu Chiu, Hui-Yu Chen
We present a polarization Linnik interference microscope with a nematic liquid-crystal (NLC) phase shifter for full-field optical coherence tomography of high-quality images. The rotating half-wave plate in conventional achromatic phase shifters was replaced by three liquid-crystal (LC) half-wave ... [Virtual J. Biomed. Opt. 51, 1361-1366 (2012)]
We present a polarization Linnik interference microscope with a nematic liquid-crystal (NLC) phase shifter for full-field optical coherence tomography of high-quality images. The rotating half-wave plate in conventional achromatic phase shifters was replaced by three liquid-crystal (LC) half-wave ... [Virtual J. Biomed. Opt. 51, 1361-1366 (2012)]
Nano-lens diffraction around a single heated nano particle
Markus Selmke, Marco Braun, Frank Cichos
The action of a nanoscopic spherically symmetric refractive index profile on a focused Gaussian beam may easily be envisaged as the action of a phase-modifying element, i.e. a lens: Rays traversing the inhomogeneous refractive index field n(r) collect an additional phase along their trajectory ... [Virtual J. Biomed. Opt. 20, 8055-8070 (2012)]
The action of a nanoscopic spherically symmetric refractive index profile on a focused Gaussian beam may easily be envisaged as the action of a phase-modifying element, i.e. a lens: Rays traversing the inhomogeneous refractive index field n(r) collect an additional phase along their trajectory ... [Virtual J. Biomed. Opt. 20, 8055-8070 (2012)]
Photonic-crystal membranes for optical detection of single nano-particles, designed for biosensor application
Jon Olav Grepstad, Peter Kaspar, Olav Solgaard, Ib-Rune Johansen, Aasmund S. Sudbø
A sensor designed to detect bio-molecules is presented. The sensor exploits a planar 2D photonic crystal (PC) membrane with sub-micron thickness and through holes, to induce high optical fields that allow detection of nano-particles smaller than the diffraction limit of an optical microscope. We ... [Virtual J. Biomed. Opt. 20, 7954-7965 (2012)]
A sensor designed to detect bio-molecules is presented. The sensor exploits a planar 2D photonic crystal (PC) membrane with sub-micron thickness and through holes, to induce high optical fields that allow detection of nano-particles smaller than the diffraction limit of an optical microscope. We ... [Virtual J. Biomed. Opt. 20, 7954-7965 (2012)]
Comparative intrinsic optical signal imaging of wild-type and mutant mouse retinas
Qiu-Xiang Zhang, Youwen Zhang, Rong-Wen Lu, Yi-Chao Li, Steven J. Pittler, Timothy W. Kraft, Xin-Cheng Yao
Functional measurement is important for retinal study and disease diagnosis. Transient intrinsic optical signal (IOS) response, tightly correlated with functional stimulation, has been previously detected in normal retinas. In this paper, comparative IOS imaging of wild-type (WT) and ... [Virtual J. Biomed. Opt. 20, 7646-7654 (2012)]
Functional measurement is important for retinal study and disease diagnosis. Transient intrinsic optical signal (IOS) response, tightly correlated with functional stimulation, has been previously detected in normal retinas. In this paper, comparative IOS imaging of wild-type (WT) and ... [Virtual J. Biomed. Opt. 20, 7646-7654 (2012)]
High-resolution imaging of microvasculature in human skin in-vivo with optical coherence tomography
Gangjun Liu, Wangcun Jia, Victor Sun, Bernard Choi, Zhongping Chen
In this paper, the features of the intensity-based Doppler variance (IBDV) method were analyzed systemically with a flow phantom. The effects of beam scanning density, flow rate and the time interval between neighboring A-lines on the performance of this method were investigated. The IBDV method ... [Virtual J. Biomed. Opt. 20, 7694-7705 (2012)]
In this paper, the features of the intensity-based Doppler variance (IBDV) method were analyzed systemically with a flow phantom. The effects of beam scanning density, flow rate and the time interval between neighboring A-lines on the performance of this method were investigated. The IBDV method ... [Virtual J. Biomed. Opt. 20, 7694-7705 (2012)]
Unconventional structure-assisted optical manipulation of high-index nanowires in liquid crystals
David Engström, Michael C.M. Varney, Martin Persson, Rahul P. Trivedi, Kris A. Bertness, Mattias Goksör, Ivan I. Smalyukh
Stable optical trapping and manipulation of high-index particles in low-index host media is often impossible due to the dominance of scattering forces over gradient forces. Here we explore optical manipulation in liquid crystalline structured hosts and show that robust optical manipulation of ... [Virtual J. Biomed. Opt. 20, 7741-7748 (2012)]
Stable optical trapping and manipulation of high-index particles in low-index host media is often impossible due to the dominance of scattering forces over gradient forces. Here we explore optical manipulation in liquid crystalline structured hosts and show that robust optical manipulation of ... [Virtual J. Biomed. Opt. 20, 7741-7748 (2012)]
Detailed validation of the bidirectional effect in various Case I and Case II waters
Arthur C.R. Gleason, Kenneth J. Voss, Howard R. Gordon, Michael Twardowski, James Sullivan, Charles Trees, Alan Weidemann, Jean-François Berthon, Dennis Clark, Zhong-Ping Lee
Simulated bidirectional reflectance distribution functions (BRDF) were compared with measurements made just beneath the water’s surface. In Case I water, the set of simulations that varied the particle scattering phase function depending on chlorophyll concentration agreed more closely with ... [Virtual J. Biomed. Opt. 20, 7630-7645 (2012)]
Simulated bidirectional reflectance distribution functions (BRDF) were compared with measurements made just beneath the water’s surface. In Case I water, the set of simulations that varied the particle scattering phase function depending on chlorophyll concentration agreed more closely with ... [Virtual J. Biomed. Opt. 20, 7630-7645 (2012)]
Analytic model for the direct and diffuse components of downwelling spectral irradiance in water
Peter Gege
The direct and diffuse components of downwelling irradiance have in general different path lengths in water, and hence they decrease differently with sensor depth. Furthermore, the ever-changing geometry of a wind-roughened and wave-modulated water surface induces uncorrelated intensity changes to ... [Virtual J. Biomed. Opt. 51, 1407-1419 (2012)]
The direct and diffuse components of downwelling irradiance have in general different path lengths in water, and hence they decrease differently with sensor depth. Furthermore, the ever-changing geometry of a wind-roughened and wave-modulated water surface induces uncorrelated intensity changes to ... [Virtual J. Biomed. Opt. 51, 1407-1419 (2012)]
Collective behavior of impedance matched plasmonic nanocavities
A. Polyakov, M. Zolotorev, P. J. Schuck, H. A. Padmore
Nanometer sized cavities arranged as a subwavelength metallic grating can provide omni-directional and complete absorption of light. We present an explanation of this extraordinary phenomenon as a collective resonant response of a system based on a surface impedance model. This model gives a ... [Virtual J. Biomed. Opt. 20, 7685-7693 (2012)]
Nanometer sized cavities arranged as a subwavelength metallic grating can provide omni-directional and complete absorption of light. We present an explanation of this extraordinary phenomenon as a collective resonant response of a system based on a surface impedance model. This model gives a ... [Virtual J. Biomed. Opt. 20, 7685-7693 (2012)]
Improved 800 nm emission of Tm^3+ sensitized by Yb^3+ and Ho^3+ in β-NaYF_4 nanocrystals under 980 nm excitation
Lili Wang, Weiping Qin, Zhenyu Liu, Dan Zhao, Guanshi Qin, Weihua Di, Chunfeng He
In vitro and in vivo bioimaging, Yb/Tm doped fluoride nanocrystals (NCs) as nanoprobes have attracted much attention due to their near infrared (NIR) upconversion (UC) emission at 800 nm under NIR 980 nm excitation. Our paper presents a simple and general method which can further improve the ... [Virtual J. Biomed. Opt. 20, 7602-7607 (2012)]
In vitro and in vivo bioimaging, Yb/Tm doped fluoride nanocrystals (NCs) as nanoprobes have attracted much attention due to their near infrared (NIR) upconversion (UC) emission at 800 nm under NIR 980 nm excitation. Our paper presents a simple and general method which can further improve the ... [Virtual J. Biomed. Opt. 20, 7602-7607 (2012)]
Adaptive synthetic-aperture focusing technique for microvasculature imaging using photoacoustic microscopy
Zilin Deng, Xiaoquan Yang, Hui Gong, Qingming Luo
To improve the lateral resolution of the blood vessels along arbitrary direction out of focus in photoacoustic microscopy (PAM), we propose an adaptive synthetic-aperture focusing technique (ASAFT) for microvasculature imaging which can be automatically applied to each branch of blood vessels, ... [Virtual J. Biomed. Opt. 20, 7555-7563 (2012)]
To improve the lateral resolution of the blood vessels along arbitrary direction out of focus in photoacoustic microscopy (PAM), we propose an adaptive synthetic-aperture focusing technique (ASAFT) for microvasculature imaging which can be automatically applied to each branch of blood vessels, ... [Virtual J. Biomed. Opt. 20, 7555-7563 (2012)]
Automated measurement of choroidal thickness in the human eye by polarization sensitive optical coherence tomography
Teresa Torzicky, Michael Pircher, Stefan Zotter, Marco Bonesi, Erich Götzinger, Christoph K. Hitzenberger
We present a new method to automatically segment the thickness of the choroid in the human eye by polarization sensitive optical coherence tomography (PS-OCT). A swept source PS-OCT instrument operating at a center wavelength of 1040 nm is used. The segmentation method is based entirely on ... [Virtual J. Biomed. Opt. 20, 7564-7574 (2012)]
We present a new method to automatically segment the thickness of the choroid in the human eye by polarization sensitive optical coherence tomography (PS-OCT). A swept source PS-OCT instrument operating at a center wavelength of 1040 nm is used. The segmentation method is based entirely on ... [Virtual J. Biomed. Opt. 20, 7564-7574 (2012)]
Silicon-Germanium multi-quantum well photodetectors in the near infrared
Efe Onaran, M. Cengiz Onbasli, Alper Yesilyurt, Hyun Yong Yu, Ammar M. Nayfeh, Ali K. Okyay
Single crystal Silicon-Germanium multi-quantum well layers were epitaxially grown on silicon substrates. Very high quality films were achieved with high level of control utilizing recently developed MHAH epitaxial technique. MHAH growth technique facilitates the monolithic integration of photonic ... [Virtual J. Biomed. Opt. 20, 7608-7615 (2012)]
Single crystal Silicon-Germanium multi-quantum well layers were epitaxially grown on silicon substrates. Very high quality films were achieved with high level of control utilizing recently developed MHAH epitaxial technique. MHAH growth technique facilitates the monolithic integration of photonic ... [Virtual J. Biomed. Opt. 20, 7608-7615 (2012)]
Quantitative phase microscopy using dual-plane in-line digital holography
Bhargab Das, Chandra S. Yelleswarapu, D. V. G. L. N. Rao
We present detailed theoretical evaluation and thorough experimental investigation of quantitative phase imaging using our previously demonstrated dual-plane in-line digital holographic microscopy technique [Opt. Lett.35, 3426 (2010)10.1364/OL.35.003426OPLEDP0146-9592]. This evaluation is based on ... [Virtual J. Biomed. Opt. 51, 1387-1395 (2012)]
We present detailed theoretical evaluation and thorough experimental investigation of quantitative phase imaging using our previously demonstrated dual-plane in-line digital holographic microscopy technique [Opt. Lett.35, 3426 (2010)10.1364/OL.35.003426OPLEDP0146-9592]. This evaluation is based on ... [Virtual J. Biomed. Opt. 51, 1387-1395 (2012)]
Strategies to maximize the performance of a STED microscope
Silvia Galiani, Benjamin Harke, Giuseppe Vicidomini, Gabriele Lignani, Fabio Benfenati, Alberto Diaspro, Paolo Bianchini
In stimulated emission depletion (STED) microscopy, the spatial resolution scales as the inverse square root of the STED beam's intensity. However, to fully exploit the maximum effective resolution achievable for a given STED beam’s intensity, several experimental precautions have to be ... [Virtual J. Biomed. Opt. 20, 7362-7374 (2012)]
In stimulated emission depletion (STED) microscopy, the spatial resolution scales as the inverse square root of the STED beam's intensity. However, to fully exploit the maximum effective resolution achievable for a given STED beam’s intensity, several experimental precautions have to be ... [Virtual J. Biomed. Opt. 20, 7362-7374 (2012)]
Confocal surface plasmon microscopy with pupil function engineering
Bei Zhang, Suejit Pechprasarn, Jing Zhang, Michael G. Somekh
Surface Plasmon microscopy can measure local changes of refractive index on the micron scale. Interferometric plasmon imaging delivers quantitative high spatial resolution sensitive to refractive index. In addition the so called V(z) method allows image contrast to be controlled by varying the ... [Virtual J. Biomed. Opt. 20, 7388-7397 (2012)]
Surface Plasmon microscopy can measure local changes of refractive index on the micron scale. Interferometric plasmon imaging delivers quantitative high spatial resolution sensitive to refractive index. In addition the so called V(z) method allows image contrast to be controlled by varying the ... [Virtual J. Biomed. Opt. 20, 7388-7397 (2012)]
Generation of photorealistic 3D image using optical digitizer
X. M. Liu, X. Peng, Y. K. Yin, A. M. Li, X. L. Liu, W. Wu
A technique to generate a photorealistic three-dimensional (3D) image and color-textured model using a dedicated optical digitizer is presented. The proposed technique is started with the range and texture image acquisition from different viewpoints, followed by the registration and integration of ... [Virtual J. Biomed. Opt. 51, 1304-1311 (2012)]
A technique to generate a photorealistic three-dimensional (3D) image and color-textured model using a dedicated optical digitizer is presented. The proposed technique is started with the range and texture image acquisition from different viewpoints, followed by the registration and integration of ... [Virtual J. Biomed. Opt. 51, 1304-1311 (2012)]
Drift estimation for single marker switching based imaging schemes
Claudia Geisler, Thomas Hotz, Andreas Schönle, Stefan W. Hell, Axel Munk, Alexander Egner
In recent years, the diffraction barrier in fluorescence imaging has been broken and optical nanoscopes now routinely image with resolutions of down to 20 nm, an improvement of more than 10 fold. Because this allows imaging much smaller features and because all super-resolution approaches trade off ... [Virtual J. Biomed. Opt. 20, 7274-7289 (2012)]
In recent years, the diffraction barrier in fluorescence imaging has been broken and optical nanoscopes now routinely image with resolutions of down to 20 nm, an improvement of more than 10 fold. Because this allows imaging much smaller features and because all super-resolution approaches trade off ... [Virtual J. Biomed. Opt. 20, 7274-7289 (2012)]
Incorporation of an experimentally determined MTF for spatial frequency filtering and deconvolution during optical projection tomography reconstruction
Lingling Chen, James McGinty, Harriet B. Taylor, Laurence Bugeon, Jonathan R. Lamb, Margaret J. Dallman, Paul M. W. French
We demonstrate two techniques to improve the quality of reconstructed optical projection tomography (OPT) images using the modulation transfer function (MTF) as a function of defocus experimentally determined from tilted knife-edge measurements. The first employs a 2-D binary filter based on the ... [Virtual J. Biomed. Opt. 20, 7323-7337 (2012)]
We demonstrate two techniques to improve the quality of reconstructed optical projection tomography (OPT) images using the modulation transfer function (MTF) as a function of defocus experimentally determined from tilted knife-edge measurements. The first employs a 2-D binary filter based on the ... [Virtual J. Biomed. Opt. 20, 7323-7337 (2012)]
Measurement of light absorption by aquatic particles: improvement of the quantitative filter technique by use of an integrating sphere approach
Rüdiger Röttgers, Steffen Gehnke
Determination of particulate absorption in natural waters is often made by measuring the transmittance of samples on glass-fiber filters with the so-called quantitative filter technique (QFT). The accuracy of this technique is limited due to ... [Virtual J. Biomed. Opt. 51, 1336-1351 (2012)]
Determination of particulate absorption in natural waters is often made by measuring the transmittance of samples on glass-fiber filters with the so-called quantitative filter technique (QFT). The accuracy of this technique is limited due to ... [Virtual J. Biomed. Opt. 51, 1336-1351 (2012)]
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- …
- nächste Seite ›
- letzte Seite »
