Affiliation: National University of Singapore
- Multi-contrast focal modulation microscopy for in vivo imaging of thick biological tissuesNanGuang Chen
Department of Bioengineering, Faculty of Engineering, National University of Singapore, Singapore 117576, Singapore
Opt Express 20:12166-70. 2012....
- Controlled Monte Carlo method for light propagation in tissue of semi-infinite geometryNanGuang Chen
Division of Bioengineering and the Department of Electrical and Computer Engineering, National University of Singapore, Singapore
Appl Opt 46:1597-603. 2007..Consequently, path-length resolved photon trajectories can be generated with a significantly improved efficiency. We report a more than 29 times reduction in simulation time for early arriving photons in a typical configuration...
- Focal modulation microscopyNanGuang Chen
Division of Bioengineering, National University of Singapore, Singapore
Opt Express 16:18764-9. 2008..Our method has been validated with animal tissue and an imaging depth around 600 microns has been demonstrated...
- Edge enhancement for in-phase focal modulation microscopeKe Si
Graduate School for Integrative Sciences and Engineering, National University of Singapore, 10 Medical Drive, Singapore 117597, Singapore
Appl Opt 48:6290-5. 2009..4% and 58.9% for a thick edge and a thin edge, respectively. Signal level is also discussed, and the results show that, to obtain high transverse resolution with IPFMM, the normalized detector pinhole radius should not exceed 2.8...
- Focal modulation microscopy: a theoretical studyShau Poh Chong
Division of Bioengineering, National University of Singapore, 9 Engineering Drive 1, EA 03 12, Singapore 129789
Opt Lett 35:1804-6. 2010..The scalar diffraction theory is combined with Monte Carlo simulation to evaluate the signal-to-background ratio at various depths. The performance of confocal microscopy with a similar optical setup is also evaluated for comparison...
- Focal modulation microscopy with annular apertures: a numerical studyWei Gong
Division of Bioengineering, National University of Singapore, Singapore, Singapore
J Biophotonics 3:476-84. 2010..The capability of background rejection is also investigated, showing AFMM has the potential to further increase the imaging penetration depth. Finally, an optimal configuration of AFMM is elaborated...
- Fast time-domain diffuse optical tomography using pseudorandom bit sequencesWeirong Mo
Division of Bioengineering, National University of Singapore, Singapore
Opt Express 16:13643-50. 2008..The high signal-to-noise ratio and the environmental illumination insensitivity warrant a great potential for applications in clinical noninvasive breast cancer detection...
- Considerations of aperture configuration in focal modulation microscopy from the standpoint of modulation depthGuangjun Gao
Division of Bioengineering, National University of Singapore, Singapore 117576
J Opt Soc Am A Opt Image Sci Vis 28:496-501. 2011..In summary, the annular configuration is superior to the fan- and stripe-shaped configurations in modulation depth and spatial resolution...
- Simple spatial phase modulator for focal modulation microscopyChee Howe Wong
Department of Electrical and Computer Engineering, National University of Singapore, Singapore
Appl Opt 48:3237-42. 2009..We have designed a simple spatial phase modulator based on a tilting glass plate that provides superb modulation stability. Image quality has been improved remarkably after integrating such a modulator into a FMM system...
- Improved spatial resolution in fluorescence focal modulation microscopyWei Gong
Division of Bioengineering, National University of Singapore, Singapore 117576, Singapore
Opt Lett 34:3508-10. 2009..4%. When applied to saturable fluorescence, the half-width at half-maximum is improved by 33.6%, 50.0%, and 62.9%, at demodulation frequencies 2omega, 4omega, and 8omega, respectively...
- Multistage inversion algorithm for biological tissue imagingKrishna Agarwal
National University of Singapore, Department of Electrical and Computer Engineering, Singapore
J Biomed Opt 15:016007. 2010..The method reduces the ill-posedness of the image reconstruction problem iteratively such that good imaging results are obtained for multiple heterogeneities having complicated geometries even in the presence of 3% additive white noise...
- Quantitative characterization of optical and physiological parameters in normal breasts using time-resolved spectroscopy: in vivo results of 19 Singapore womenWeirong Mo
National University of Singapore, Division of Bioengineering, Faculty of Engineering, Singapore
J Biomed Opt 14:064004. 2009..These in vivo experiment results will contribute to the breast tissue diagnosis between healthy and diseased breast tissues...
- Recent advances in optical microscopy methods for subcellular imaging of thick biological tissuesNanGuang Chen
Department of Biomedical Engineering, National University of Singapore, Singapore
Crit Rev Biomed Eng 41:393-403. 2013..Focal modulation microscopy has demonstrated an imaging depth comparable to those of multiphoton microscopy and optical coherence microscopy, near-real-time image acquisition, and capability with a multiple contrast mechanism. ..
- Plasmonic chiral contrast agents for optical coherence tomography: numerical studyKalpesh B Mehta
Optical Bioimaging Lab, Division of Bioengineering, National University of Singapore, 7 Engineering Drive 1, Blk E3A, 04 15, Singapore 117574, Singapore
Opt Express 19:14903-12. 2011..The proposed contrast agents may extend the applicability of OCT to the problems that require the molecular contrast with enhanced sensitivity...
- Ultra long high resolution beam by multi-zone rotationally symmetrical complex pupil filterYingshun Xu
Division of Bioengineering, National University of Singapore, 7 Engineering Drive 1, 117574, Singapore
Opt Express 15:6409-13. 2007..The scalar diffraction theory is used to optimize the zone parameters. Simulation results show that extended DoF of the beam is increased by 16 times while the spot size at the beam waist is reduced to 0.7 times...
- Superresolution along extended depth of focus with binary-phase filters for the Gaussian beamLinbo Liu
Graduate Programme in Bioengineering, National University of Singapore, Singapore
J Opt Soc Am A Opt Image Sci Vis 25:2095-101. 2008..Optimal filter designs are proposed for either high-resolution or ultra-large-DOF applications followed by experimental verifications...
- Optimization of source and detector configurations based on Cramer-Rao lower bound analysisLing Chen
National University of Singapore, Division of Bioengineering, Faculty of Engineering, Singapore, Singapore
J Biomed Opt 16:035001. 2011..It is demonstrated that the SD sets selected by this method afford better reconstructed images. This methodology can be adapted to other probe surfaces and other imaging geometries...
- Double-reflection polygon mirror for high-speed optical coherence microscopyLinbo Liu
Graduate Programme in Bioengineering, National University of Singapore 117576, Singapore
Opt Lett 32:3528-30. 2007..8 degrees scanning range, and 90% duty cycle. A much higher scanning speed and much larger scanning range can be readily achieved by increasing the scanner diameter...
- Emission and absorption properties of indocyanine green in Intralipid solutionBaohong Yuan
Department of Electrical and Computer Engineering, University of Connecticut, Storrs, CT 06269 1157, USA
J Biomed Opt 9:497-503. 2004..Also, in the concentration range of 0 to 2 microM, ICG solution always has a higher absorption coefficient at wavelength 830 nm than that at 660 nm, which is quite different from the ICG in water case...
- Imaging tumor angiogenesis by use of combined near-infrared diffusive light and ultrasoundQuing Zhu
Department of Electrical and Computer Engineering, University of Connecticut, Storrs, Connecticut 06269 2157, USA
Opt Lett 28:337-9. 2003..It is shown that detailed distributions of wavelength-dependent absorption and hemoglobin concentration of breast carcinoma can be obtained with the new reconstruction scheme...