scholarly journals Orienting to Polarized Light at Night—Matching Lunar Skylight to Performance in a Nocturnal Beetle

2018 ◽  
Author(s):  
James J. Foster ◽  
John D. Kirwan ◽  
Basil el Jundi ◽  
Jochen Smolka ◽  
Lana Khaldy ◽  
...  
Keyword(s):  
South African ◽  
Polarized Light ◽  
Dung Beetle ◽  
Degree Of Polarization ◽  
Specific Reference ◽  
Lunar Phase ◽  
Orientation Behaviour ◽  
Linearly Polarized ◽  
Summary Statement ◽  
Night Sky

AbstractFor polarized light to inform behaviour, the typical range of degrees of polarization observable in the animal’s natural environment must be above the threshold for detection and interpretation. Here we present the first investigation of the degree of linear polarization threshold for orientation behaviour in a nocturnal species, with specific reference to the range of degrees of polarization measured in the night sky. An effect of lunar phase on the degree of polarization of skylight was found, with smaller illuminated fractions of the moon’s surface corresponding to lower degrees of polarization in the night sky. We found that South African dung beetleEscarabaeus satyrus(Boheman, 1860) can orient to polarized light for a range of degrees of polarization similar to that observed in diurnal insects, reaching a lower threshold between 0.04 and 0.32, possibly as low as 0.11. For degrees of polarization lower than 0.23, as measured on a crescent moon night, orientation performance was considerably weaker than that observed for completely linearly-polarized stimuli, but was nonetheless stronger than in the absence of polarized light.Summary StatementA degree-of-polarization threshold for orientation behaviour is reported for nocturnal dung beetleEscarabaeus satyrusin the context of measurements showing changes in the degree of polarization of skylight with lunar phase.

scholarly journals The linearly polarized light field in clear, tropical marine waters: spatial and temporal variation of light intensity, degree of polarization and e-vector angle

2001 ◽  
Vol 204 (14) ◽  
pp. 2461-2467 ◽  
Author(s):  
Thomas W. Cronin ◽  
Nadav Shashar
Keyword(s):  
Light Field ◽  
Marine Invertebrates ◽  
Polarized Light ◽  
Florida Keys ◽  
Degree Of Polarization ◽  
Spatial And Temporal Variation ◽  
Polarization Sensitivity ◽  
Marine Animals ◽  
Linearly Polarized ◽  
Vector Angle

SUMMARYSensitivity to polarized light is widespread among marine animals, including crustaceans, cephalopods and some fishes. They use this ability to orient and find prey, and possibly for a number of other visual tasks. Unlike the ultraviolet-sensitive polarization receptors of most insects, the polarization receptors of marine invertebrates tend to be maximally sensitive near 500nm, suggesting that polarized light in water differs from that in air. The underwater field of partially linearly polarized light has been studied for nearly 50 years, but data are still limited and sparse. We measured the submarine polarized light field from 350 to 600nm throughout the day on a coral reef in the Florida Keys at a depth of 15m using the underwater laboratory Aquarius as a research platform. Our results show that the angle of polarization as viewed along any given line of sight at this depth is a relatively simple function of solar position and that the degree of polarization is greatest 60–90° from the sun. Both e-vector angle and degree of polarization vary only slightly with wavelength, although light is sometimes less polarized in the ultraviolet. Since light is most intense at medium wavelengths and polarization is nearly maximal at these wavelengths, invertebrate polarization photoreceptors are spectrally well placed. Also, the relative spectral constancy of the angle and degree of polarization supports fish polarization sensitivity, which relies on spectrally diverse photoreceptor sets.

Daphnia pulex swims towards the most strongly polarized light - a response that leads to ‘shore flight’

1999 ◽  
Vol 202 (24) ◽  
pp. 3631-3635 ◽  
Author(s):  
R. Schwind
Keyword(s):  
Visual Field ◽  
Rayleigh Scattering ◽  
Daphnia Pulex ◽  
Polarized Light ◽  
Open Water ◽  
The Other ◽  
Lower Degree ◽  
Degree Of Polarization ◽  
Large Area ◽  
Linearly Polarized

When Daphnia pulex are presented on one side of their visual field with diffuse, large-area linearly polarized light with a horizontal e-vector and on the other side of their visual field with large-area polarized light with a lower degree of polarization, they swim towards the place with the higher degree of polarization. The response is intensity-invariant: Daphnia pulex swim towards the place of maximal polarization regardless of which side of their visual field has the higher intensity of light. As a result of Rayleigh scattering in a pond, the light surrounding the Daphnia is polarized and has a horizontal e-vector. Near the shore, polarization is not homogeneous. The light seen in the direction of the open water has a higher degree of polarization than that seen in the direction towards the shore. Therefore, in a pond, swimming towards the place with the highest degree of polarization leads the Daphnia away from the shore. For Daphnia, this response explains a mechanism that underlies the well-known phenomenon of ‘shore flight’, the active departure of small pelagic crustaceans from shore zones.

scholarly journals Why do horseflies need polarization vision for host detection? Polarization helps tabanid flies to select sunlit dark host animals from the dark patches of the visual environment

2017 ◽  
Vol 4 (11) ◽  
pp. 170735 ◽  
Author(s):  
Gábor Horváth ◽  
Tamás Szörényi ◽  
Ádám Pereszlényi ◽  
Balázs Gerics ◽  
Ramón Hegedüs ◽  
...  
Keyword(s):  
Polarized Light ◽  
Degree Of Polarization ◽  
Polarization Sensitivity ◽  
Host Animal ◽  
Linearly Polarized ◽  
Imaging Polarimetry ◽  
Host Detection ◽  
Vegetation Region ◽  
Two Parameters ◽  
Polarization Of Light

Horseflies (Tabanidae) are polarotactic, being attracted to linearly polarized light when searching for water or host animals. Although it is well known that horseflies prefer sunlit dark and strongly polarizing hosts, the reason for this preference is unknown. According to our hypothesis, horseflies use their polarization sensitivity to look for targets with higher degrees of polarization in their optical environment, which as a result facilitates detection of sunlit dark host animals. In this work, we tested this hypothesis. Using imaging polarimetry, we measured the reflection–polarization patterns of a dark host model and a living black cow under various illumination conditions and with different vegetation backgrounds. We focused on the intensity and degree of polarization of light originating from dark patches of vegetation and the dark model/cow. We compared the chances of successful host selection based on either intensity or degree of polarization of the target and the combination of these two parameters. We show that the use of polarization information considerably increases the effectiveness of visual detection of dark host animals even in front of sunny–shady–patchy vegetation. Differentiation between a weakly polarizing, shady (dark) vegetation region and a sunlit, highly polarizing dark host animal increases the efficiency of host search by horseflies.

scholarly journals Metasurface of Combined Semicircular Rings with Orthogonal Slit Pairs for Generation of Dual Vector Beams

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1718
Author(s):  
Qian Kong ◽  
Manna Gu ◽  
Xiangyu Zeng ◽  
Rui Sun ◽  
Yuqin Zhang ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Polarized Light ◽  
Orientation Angle ◽  
Fdtd Simulation ◽  
Dual Vector ◽  
Vector Beams ◽  
Linearly Polarized ◽  
Potential Applications ◽  
Difference Time

Manipulation of multichannel vector beams (VBs) with metasurfaces is an important topic and holds potential applications in information technology. In this paper, we propose a novel metasurface for the generation of dual VBs, which is composed of orthogonal slit pairs arranged on multiple groups of combined semicircular rings (CSRs). A group of CSRs include a right-shifted set and a left-shifted set of semicircular rings, and each set of semicircular rings has two halves of circles with different radii, sharing the same shifted center. Under the illumination of linearly polarized light, the two shifted sets of semicircular rings generate the two VBs at the shifted center positions on the observation plane. The slit units of each set are designed with independent rotation order and initial orientation angle. By adjusting the linear polarization of illumination, both two VBs with their orders and polarization states are independently controlled simultaneously. The principle and design are demonstrated by the finite-difference time domain (FDTD) simulation. The work is of significance for miniatured devices of VB generators and for related applications.

scholarly journals Formation of half-period surface relief gratings in azobenzene containing polymer films

2020 ◽  
Vol 126 (9) ◽  
Author(s):  
Joachim Jelken ◽  
Carsten Henkel ◽  
Svetlana Santer
Keyword(s):  
Polymer Film ◽  
Polymer Films ◽  
Surface Relief ◽  
Incident Light ◽  
Glassy State ◽  
Polarized Light ◽  
Half Period ◽  
Polarization Distribution ◽  
Linearly Polarized ◽  
Set Up

Abstract We study the peculiar response of photo-sensitive polymer films irradiated with a certain type of interference pattern where one interfering beam is S-polarized, while the second one is P-polarized. The polymer film, although in a glassy state, deforms following the local polarization distribution of the incident light, and a surface relief grating (SRG) appears whose period is half the optical one. All other types of interference patterns result in the matching of both periods. The topographical response is triggered by the alignment of photo-responsive azobenzene containing polymer side chains orthogonal to the local electrical field, resulting in a bulk birefringence grating (BBG). We investigate the process of dual grating formation (SRG and BBG) in a polymer film utilizing a dedicated set-up that combines probe beam diffraction and atomic force microscopy (AFM) measurements, and permits acquiring in situ and in real-time information about changes in local topography and birefringence. We find that the SRG maxima appear at the positions of linearly polarized light (tilted by 45° relative to the grating vector), causing the formation of the half-period topography. This permits to inscribe symmetric and asymmetric topography gratings with sub-wavelength period, while changing only slightly the polarization of one of the interfering beams. We demonstrate an easy generation of sawtooth profiles (blazed gratings) with adjustable shape. With these results, we have taken a significant step in understanding the photo-induced deformation of azo-polymer films.

Study of orientational order of some nematogenic compounds by spectroscopy methods using linearly polarized light

2005 ◽  
Vol 744-747 ◽  
pp. 307-313 ◽  
Author(s):  
D. Bauman ◽  
E. Chrzumnicka ◽  
E. Mykowska ◽  
M. Szybowicz ◽  
N. Grzelczak
Keyword(s):  
Orientational Order ◽  
Polarized Light ◽  
Linearly Polarized

scholarly journals Constraints on Lorentz Invariance Violation with Multiwavelength Polarized Astrophysical Sources

Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 44
Author(s):  
Qi-Qi Zhou ◽  
Shuang-Xi Yi ◽  
Jun-Jie Wei ◽  
Xue-Feng Wu
Keyword(s):  
Gamma Ray ◽  
Lorentz Invariance ◽  
Polarized Light ◽  
Polarization Plane ◽  
Polarization Angle ◽  
Intrinsic Polarization ◽  
Frequency Dependent ◽  
Invariance Violation ◽  
Linearly Polarized ◽  
Order Of Magnitude

Possible violations of Lorentz invariance (LIV) can produce vacuum birefringence, which results in a frequency-dependent rotation of the polarization plane of linearly polarized light from distant sources. In this paper, we try to search for a frequency-dependent change of the linear polarization angle arising from vacuum birefringence in the spectropolarimetric data of astrophysical sources. We collect five blazars with multiwavelength polarization measurements in different optical bands (UBVRI). Taking into account the observed polarization angle contributions from both the intrinsic polarization angle and the rotation angle induced by LIV, and assuming that the intrinsic polarization angle is an unknown constant, we obtain new constraints on LIV by directly fitting the multiwavelength polarimetric data of the five blazars. Here, we show that the birefringence parameter η quantifying the broken degree of Lorentz invariance is limited to be in the range of −9.63×10−8<η<6.55×10−6 at the 2σ confidence level, which is as good as or represents one order of magnitude improvement over the results previously obtained from ultraviolet/optical polarization observations. Much stronger limits can be obtained by future multiwavelength observations in the gamma-ray energy band.

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