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Shih Yau Lu

Bio: Shih Yau Lu is an academic researcher from University of Alabama in Huntsville. The author has contributed to research in topics: Mueller calculus & Polarization (waves). The author has an hindex of 5, co-authored 7 publications receiving 1439 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors decompose a Mueller matrix into a sequence of three matrix factors: a diattenuator, followed by a retarder, then followed by depolarizer.
Abstract: We present an algorithm that decomposes a Mueller matrix into a sequence of three matrix factors: a diattenuator, followed by a retarder, then followed by a depolarizer. Those factors are unique except for singular Mueller matrices. Based on this decomposition, the diattenuation and the retardance of a Mueller matrix can be defined and computed. Thus this algorithm is useful for performing data reduction upon experimentally determined Mueller matrices.

1,220 citations

Journal ArticleDOI
TL;DR: In this paper, the classification of polarization properties of polarization elements is studied to derive data-reduction equations for extracting the diattenuation, retardance, and other polarization properties from their Jones matrices.
Abstract: The classification of polarization properties of polarization elements is studied to derive data-reduction equations for extracting the diattenuation, retardance, and other polarization properties from their Jones matrices. Polarization elements, and Jones matrices as well, are divided into two classes: homogeneous, with orthogonal eigenpolarizations, and inhomogeneous, with nonorthogonal eigenpolarizations. The basic polarization properties, diattenuation and retardance, of homogeneous polarization elements are straightforward and well known; these elements are characterized by their eigenvalues and eigenpolarizations. Polarization properties of inhomogeneous polarization elements are not so evident. By applying polar decomposition, the definitions of diattenuation and retardance are generalized to inhomogeneous polarization elements, providing an understanding of their polarization characteristics. Furthermore, an inhomogeneity parameter is introduced to describe the degree of inhomogeneity in a polarization element. These results are then adapted to degenerate polarization elements, which have only one linearly independent eigenpolarization.

261 citations

Journal ArticleDOI
TL;DR: In this article, it was shown that only polarizers, retarders, and improper rotation Mueller matrices do not decrease the degree of polarization for any input Stokes vector, and that an unpolarized incident Stokes vectors always has the maximum gain in the level of polarization.

69 citations

Journal ArticleDOI
TL;DR: The depolarization of a TVT-6000 liquid-crystal television has been measured to vary between 2% and 9% as a function of bias voltage, angle of incidence, and incident polarization state.
Abstract: The depolarization of a TVT-6000 liquid-crystal television has been measured to vary between 2% and 9% as a function of bias voltage, angle of incidence, and incident polarization state

29 citations

Journal ArticleDOI
TL;DR: A spectrum for the electro-optic coefficient of cadmium telluride measured from 3 to 14 µm is reported, showing that the quantity n(3)r(41) has a nearly constant value of 1.09 × 10(-10) m/V over this spectral band.
Abstract: A spectrum for the electro-optic coefficient of cadmium telluride measured from 3 to 14 μm is reported. The spectrum shows that the quantity n3r41 has a nearly constant value of 1.09 × 10−10 m/V over this spectral band, with a slight (5%) dip at the weak absorption band centered at 6 μm. Measurements were performed with an infrared Mueller matrix spectropolarimeter. Transmission spectra of the Mueller matrix were acquired at a set of applied voltages. Retardance spectra were calculated from Mueller matrix spectra, and then the electro-optic coefficient was calculated at each wavelength by a least-squares fit to the resulting retardance as a function of voltage.

24 citations


Cited by
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Journal ArticleDOI
TL;DR: The foundations of passive imaging polarimetry, the phenomenological reasons for designing a polarimetric sensor, and the primary architectures that have been exploited for developing imaging polarimeters are discussed.
Abstract: Imaging polarimetry has emerged over the past three decades as a powerful tool to enhance the information available in a variety of remote sensing applications. We discuss the foundations of passive imaging polarimetry, the phenomenological reasons for designing a polarimetric sensor, and the primary architectures that have been exploited for developing imaging polarimeters. Considerations on imaging polarimeters such as calibration, optimization, and error performance are also discussed. We review many important sources and examples from the scientific literature.

1,374 citations

Journal ArticleDOI
TL;DR: In this paper, the authors decompose a Mueller matrix into a sequence of three matrix factors: a diattenuator, followed by a retarder, then followed by depolarizer.
Abstract: We present an algorithm that decomposes a Mueller matrix into a sequence of three matrix factors: a diattenuator, followed by a retarder, then followed by a depolarizer. Those factors are unique except for singular Mueller matrices. Based on this decomposition, the diattenuation and the retardance of a Mueller matrix can be defined and computed. Thus this algorithm is useful for performing data reduction upon experimentally determined Mueller matrices.

1,220 citations

Journal ArticleDOI
TL;DR: A summary of issues pertinent to the polarized light methodologies in tissues, including polarized light basics, Stokes-Muller formalism, methods of polarization measurements, polarized light modeling in turbid media, applications to tissue imaging, inverse analysis for polarimetric results quantification, Applications to quantitative tissue assessment, etc.
Abstract: Polarimetry has a long and successful history in various forms of clear media. Driven by their biomedical potential, the use of the polarimetric approaches for biological tissue assessment has also recently received considerable attention. Specifically, polarization can be used as an effective tool to discriminate against multiply scattered light (acting as a gating mechanism) in order to enhance contrast and to improve tissue imaging resolution. Moreover, the intrinsic tissue polarimetry characteristics contain a wealth of morphological and functional information of potential biomedical importance. However, in a complex random medium-like tissue, numerous complexities due to multiple scattering and simultaneous occurrences of many scattering and polarization events present formidable challenges both in terms of accurate measurements and in terms of analysis of the tissue polarimetry signal. In order to realize the potential of the polarimetric approaches for tissue imaging and characterization/diagnosis, a number of researchers are thus pursuing innovative solutions to these challenges. In this review paper, we summarize these and other issues pertinent to the polarized light methodologies in tissues. Specifically, we discuss polarized light basics, Stokes-Muller formalism, methods of polarization measurements, polarized light modeling in turbid media, applications to tissue imaging, inverse analysis for polarimetric results quantification, applications to quantitative tissue assessment, etc.

540 citations

Patent
13 Dec 2007
TL;DR: In this paper, a method for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (LCI) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies, is presented.
Abstract: Apparatus and method for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (“LCI”) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies. The LCI broad bandwidth source is split into N spectral bands. The N spectral bands are individually detected and processed to provide an increase in the signal-to-noise ratio by a factor of N. Each spectral band is detected by a separate photo detector and amplified. For each spectral band the signal is band pass filtered around the signal band by analog electronics and digitized, or, alternatively, the signal may be digitized and band pass filtered in software. As a consequence, the shot noise contribution to the signal is reduced by a factor equal to the number of spectral bands. The signal remains the same. The reduction of the shot noise increases the dynamic range and sensitivity of the system.

446 citations

Patent
08 Sep 2004
TL;DR: In this article, the first and/or second electro-magnetic radiations have a spectrum whose mean frequency changes substantially continuously over time at a tuning speed that is greater than 100 Tera Hertz per millisecond.
Abstract: An apparatus and method are provided. In particular, at least one first electro-magnetic radiation may be provided to a sample and at least one second electro-magnetic radiation can be provided to a non-reflective reference. A frequency of the first and/or second radiations varies over time. An interference is detected between at least one third radiation associated with the first radiation and at least one fourth radiation associated with the second radiation. Alternatively, the first electro-magnetic radiation and/or second electro-magnetic radiation have a spectrum which changes over time. The spectrum may contain multiple frequencies at a particular time. In addition, it is possible to detect the interference signal between the third radiation and the fourth radiation in a first polarization state. Further, it may be preferable to detect a further interference signal between the third and fourth radiations in a second polarization state which is different from the first polarization state. The first and/or second electro-magnetic radiations may have a spectrum whose mean frequency changes substantially continuously over time at a tuning speed that is greater than 100 Tera Hertz per millisecond.

394 citations