Multidimensional polarization sensitivity in damselfishes

2003 ◽  
Vol 189 (3) ◽  
pp. 213-220 ◽  
Author(s):  
C. W. Hawryshyn ◽  
H. D. Moyer ◽  
W. T. Allison ◽  
T. J. Haimberger ◽  
W. N. McFarland
Keyword(s):  
Polarization Sensitivity

The large photoresponse and high polarization sensitivity of Te-based optoelectronic devices with the adsorbed hydroxide ions

2021 ◽  
Vol 118 (22) ◽  
pp. 221109
Author(s):  
Le-Le Gong ◽  
Wen Xiong ◽  
Yi-Qun Xie ◽  
Jie Hu ◽  
Pu Huang ◽  
...  
Keyword(s):  
Optoelectronic Devices ◽  
Polarization Sensitivity ◽  
High Polarization

scholarly journals Synthetic polarization-sensitive optical coherence tomography by deep learning

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yi Sun ◽  
Jianfeng Wang ◽  
Jindou Shi ◽  
Stephen A. Boppart
Keyword(s):  
Optical Coherence Tomography ◽  
Deep Learning ◽  
Imaging System ◽  
Imaging Modality ◽  
Similarity Index ◽  
Polarization Sensitivity ◽  
Imaging Method ◽  
Optical Coherence ◽  
The Real ◽  
Oct Imaging

AbstractPolarization-sensitive optical coherence tomography (PS-OCT) is a high-resolution label-free optical biomedical imaging modality that is sensitive to the microstructural architecture in tissue that gives rise to form birefringence, such as collagen or muscle fibers. To enable polarization sensitivity in an OCT system, however, requires additional hardware and complexity. We developed a deep-learning method to synthesize PS-OCT images by training a generative adversarial network (GAN) on OCT intensity and PS-OCT images. The synthesis accuracy was first evaluated by the structural similarity index (SSIM) between the synthetic and real PS-OCT images. Furthermore, the effectiveness of the computational PS-OCT images was validated by separately training two image classifiers using the real and synthetic PS-OCT images for cancer/normal classification. The similar classification results of the two trained classifiers demonstrate that the predicted PS-OCT images can be potentially used interchangeably in cancer diagnosis applications. In addition, we applied the trained GAN models on OCT images collected from a separate OCT imaging system, and the synthetic PS-OCT images correlate well with the real PS-OCT image collected from the same sample sites using the PS-OCT imaging system. This computational PS-OCT imaging method has the potential to reduce the cost, complexity, and need for hardware-based PS-OCT imaging systems.

Polarization sensitivity testing of off-plane reflection gratings

2015 ◽  
Author(s):  
Hannah Marlowe ◽  
Randal L. McEntaffer ◽  
Casey T. DeRoo ◽  
Drew M. Miles ◽  
James H. Tutt ◽  
...  
Keyword(s):  
Polarization Sensitivity ◽  
Sensitivity Testing ◽  
Reflection Gratings

scholarly journals Ultraviolet polarization vision in fishes: possible mechanisms for coding e–vector

2000 ◽  
Vol 355 (1401) ◽  
pp. 1187-1190 ◽  
Author(s):  
Craig W. Hawryshyn
Keyword(s):  
Polarized Light ◽  
Spatial Arrangement ◽  
Short Review ◽  
Research Problem ◽  
Polarization Sensitivity ◽  
Polarization Vision ◽  
Selective Reflection ◽  
Mosaic Pattern ◽  
Cone Mosaic ◽  
Biophysical Mechanism

Polarization vision in vertebrates has been marked with significant controversy over recent decades. In the last decade, however, models from two laboratories have indicated that the spatial arrangement of photoreceptors provides the basis for polarization sensitivity.Work in my laboratory, in collaboration with I. Novales Flamarique and F. I. Harosi, has shown that polarization sensitivity depends on a well–defined square cone mosaic pattern and that the biophysical properties of the square cone mosaic probably account for polarization vision in the ultraviolet spectrum. The biophysical mechanism appears to be based on the selective reflection of axial–polarized light by the partitioning membrane, formed along the contact zone between the members of the double cones, onto neighbouring ultraviolet–sensitive cones. In this short review, I discuss the historical development of this research problem.

scholarly journals Polarization diversity scheme for reach extension of WDM/TDM gigabit passive optical network up to 60 km using quantum dot semiconductor optical amplifiers

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 80-84
Author(s):  
A. D. Tussupov ◽  
A. T. Tokhmetov ◽  
N. I. Listopad
Keyword(s):  
Quantum Dot ◽  
Optical Networks ◽  
Optical Amplifiers ◽  
Semiconductor Optical Amplifiers ◽  
Passive Optical Network ◽  
Advanced Technology ◽  
Polarization Sensitivity ◽  
Polarization Diversity ◽  
Design Work ◽  
Diversity Scheme

Gigabit passive optical networks (GPON) are the most advanced technology. The data transfer rate is 2.5 Gbps for downstream and 1.25 Gbps for upstreams. But this network architecture has a limited physical network length of 20 km. This is due to the high budgetary losses of the network. This restriction of access makes the network difficult to access for subscribers located far from the facilities of the telecom operator, and coverage of remote settlements is quite costly (cost of design work, fiber, laying of fiber-optic cable), thereby complicating the elimination of the digital divide between the city, the suburbs and the countryside. To solve this problem, it is proposed to use quantum dot semiconductor optical amplifiers (QD-SOA), which will expand the GPON reach up to 60 km, which is the limit for the logical length under the current protocols. Quantum dot semiconductor optical amplifiers are promising devices for optical communication technology, but for commercial use they have one disadvantage. They are polarization sensitive. In this paper the authors constructed a polarization diversity scheme to avoid polarization sensitivity of QD-SOAs.

scholarly journals TEMPERATURE DYNAMICS OF POLARIZATION SENSITIVITY SPECTRA OF INTRINSIC OXIDE–p-InSe HETEROJUNCTIONS

2013 ◽  
Vol 10 (4) ◽  
pp. 93-96
Author(s):  
В. М. Катеринчук ◽  
З. Р. Кудринський ◽  
З. Д. Ковалюк
Keyword(s):  
Polarization Sensitivity ◽  
Temperature Dynamics

scholarly journals Cloud thermodynamic phase detection with polarimetrically sensitive passive sky radiometers

2014 ◽  
Vol 7 (12) ◽  
pp. 11991-12036 ◽  
Author(s):  
K. Knobelspiesse ◽  
B. van Diedenhoven ◽  
A. Marshak ◽  
S. Dunagan ◽  
B. Holben ◽  
...  
Keyword(s):  
Near Infrared ◽  
Global Climate ◽  
Polarization Vector ◽  
Uncertainty Assessment ◽  
Polarization Sensitivity ◽  
Phase Detection ◽  
Direction Parallel ◽  
Aspect Ratios ◽  
Ice Particles ◽  
Thermodynamic Phase

Abstract. The primary goal of this project has been to investigate if ground-based visible and near-infrared passive radiometers that have polarization sensitivity can determine the thermodynamic phase of overlying clouds, i.e. if they are comprised of liquid droplets or ice particles. While this knowledge is important by itself for our understanding of the global climate, it can also help improve cloud property retrieval algorithms that use total (unpolarized) radiance to determine Cloud Optical Depth (COD). This is a potentially unexploited capability of some instruments in the NASA Aerosol Robotic Network (AERONET), which, if practical, could expand the products of that global instrument network at minimal additional cost. We performed simulations that found, for zenith observations, cloud thermodynamic phase is often expressed in the sign of the Q component of the Stokes polarization vector. We chose our reference frame as the plane containing solar and observation vectors, so the sign of Q indicates the polarization direction, parallel (positive) or perpendicular (negative) to that plane. Since the quantity of polarization is inversely proportional to COD, optically thin clouds are most likely to create a signal greater than instrument noise. Besides COD and instrument accuracy, other important factors for the determination of cloud thermodynamic phase are the solar and observation geometry (scattering angles between 40 and 60° are best), and the properties of ice particles (pristine particles may have halos or other features that make them difficult to distinguish from water droplets at specific scattering angles, while extreme ice crystal aspect ratios polarize more than compact particles). We tested the conclusions of our simulations using data from polarimetrically sensitive versions of the Cimel 318 sun photometer/radiometer that comprise AERONET. Most algorithms that exploit Cimel polarized observations use the Degree of Linear Polarization (DoLP), not the individual Stokes vector elements (such as Q). For this reason, we had no information about the accuracy of Cimel observed Q and the potential for cloud phase determination. Indeed, comparisons to ceilometer observations with a single polarized spectral channel version of the Cimel at a site in the Netherlands showed little correlation. Comparisons to Lidar observations with a more recently developed, multi-wavelength polarized Cimel in Maryland, USA, show more promise. The lack of well characterized observations has prompted us to begin the development of a small test instrument called the Sky Polarization Radiometric Instrument for Test and Evaluation (SPRITE). This instrument is specifically devoted to the accurate observation of Q, and the testing of calibration and uncertainty assessment techniques, with the ultimate goal of understanding the practical feasibility of these measurements.

Polarization analysis in the crayfish visual system

2001 ◽  
Vol 204 (14) ◽  
pp. 2383-2390 ◽  
Author(s):  
Raymon M. Glantz
Keyword(s):  
Visual System ◽  
Motor Neurons ◽  
Polarized Light ◽  
Cell Types ◽  
Afferent Input ◽  
Polarization Sensitivity ◽  
Polarization Analysis ◽  
Low Contrast ◽  
Motion Responses ◽  
Light Flashes

SUMMARY It is proposed that polarization sensitivity at the most peripheral stages of the crayfish visual system (lamina ganglionaris and medulla externa) is used to enhance contrast and thus may contribute to motion detection in low contrast environments. The four classes of visual interneurons that exhibit polarization sensitivity (lamina monopolar cells, tangential cells, sustaining fibers and dimming fibers) are not sensitive exclusively to polarized light but also respond to unpolarized contrast stimuli. Furthermore, many of these cells and the sustaining fibers in particular exhibit a greater differential e-vector responsiveness to a changing e-vector than to e-vector variations among steady-state stimuli. While all four cell types respond modestly to light flashes at an e-vector of 90° to the preferred orientation, the dynamic response to a changing e-vector is small or absent at this orientation. Because the sustaining fibers exhibit polarization sensitivity, and they provide afferent input to a subset of optomotor neurons, the latter were also tested for polarization sensitivity. The optomotor neurons involved in compensatory reflexes for body pitch were differentially sensitive to the e-vector angle of a flash of light, with maximum responses for e-vectors near the vertical. The motor neurons also exhibited a maximum response near the vertical e-vector to a continuously rotating polarizer. Two scenarios are described in which the sensitivity to a changing e-vector can produce motion responses in the absence of intensity contrast.

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