scholarly journals On the measurement of molecular anisotropies using laser techniques. II. Differential absorption of circularly and linearly polarized light

1985 ◽  
Vol 83 (6) ◽  
pp. 2632-2640 ◽  
Author(s):  
A. J. Bain ◽  
A. J. McCaffery
Keyword(s):  
Polarized Light ◽  
Differential Absorption ◽  
Linearly Polarized ◽  
Laser Techniques

scholarly journals Polarization perception in humans: on the origin of and relationship between Maxwell’s spot and Haidinger’s brushes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gary P. Misson ◽  
Shelby E. Temple ◽  
Stephen J. Anderson
Keyword(s):  
Linear Polarization ◽  
Light Absorption ◽  
Polarized Light ◽  
Retinal Images ◽  
Clinical Use ◽  
Differential Absorption ◽  
Model Simulations ◽  
Eye Disorders ◽  
Absorption Of Light ◽  
Linearly Polarized

AbstractUnder specific conditions of illumination and polarization, differential absorption of light by macular pigments is perceived as the entoptic phenomena of Maxwell’s spot (MS) or Haidinger’s brushes (HB). To simulate MS and HB, an existing computational model of polarization-dependent properties of the human macula was extended by incorporating neuronal adaptation to stabilized retinal images. The model predicted that polarized light modifies the appearance of MS leading to the perception of a novel phenomenon. The model also predicted a correlation between the observed diameters of MS and HB. Predictions were tested psychophysically in human observers, whose measured differences in the diameters of each entoptic phenomenon generated with depolarized and linearly polarized light were consistent with the model simulations. These findings support a common origin of each phenomenon, and are relevant to the clinical use of polarization stimuli in detecting and monitoring human eye disorders, including macular degeneration. We conclude: (i) MS and HB both result from differential light absorption through a radial diattenuator, compatible with the arrangement of macular pigments in Henle fibres; (ii) the morphology of MS is dependent on the degree of linear polarization; (iii) perceptual differences between MS and HB result from different states of neural adaptation.

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.

ROTATIONAL PROPERTIES OF MICRO-SLABS DRIVEN BY LINEARLY-POLARIZED LIGHT

2005 ◽  
Vol 14 (03) ◽  
pp. 375-382 ◽  
Author(s):  
CHIH-LANG LIN ◽  
IRÈNE WANG ◽  
MARC PIERRE ◽  
ISABELLE COLOMBIER ◽  
CHANTAL ANDRAUD ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Polarized Light ◽  
Polarization Plane ◽  
Light Polarization ◽  
Good Prediction ◽  
Polarization Anisotropy ◽  
Two Photon ◽  
Flat Slabs ◽  
Linearly Polarized ◽  
Optical Torque

We study the rotational motion of objects trapped in a focused laser beam (optical tweezers). Micrometer-sized flat slabs are fabricated using two-photon photopolymerization. These objects, trapped by linearly-polarized light, tend to align parallel to the polarization plane. This alignment effect is attributed to the polarization anisotropy resulting from the object shape and we present a simple electromagnetic approach to estimate the resulting optical torque. Micro-rotors of different sizes are studied experimentally. We characterize the behavior of micro-objects when the light polarization is rotated at constant speed. Our theoretical approach gives a good prediction of how the size of micro-objects affects their rotation efficiency.

Linearly polarized light absorption spectra of chlorosomes, light-harvesting antennas of photosynthetic green sulfur bacteria

2010 ◽  
Vol 484 (4-6) ◽  
pp. 333-337 ◽  
Author(s):  
Hitoshi Tamiaki ◽  
Shingo Tateishi ◽  
Shosuke Nakabayashi ◽  
Yutaka Shibata ◽  
Shigeru Itoh
Keyword(s):  
Absorption Spectra ◽  
Light Absorption ◽  
Light Harvesting ◽  
Polarized Light ◽  
Green Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Linearly Polarized ◽  
Green Sulfur
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