scholarly journals Pitch profile across the cuticle of the scarab beetle Cotinis mutabilis determined by analysis of Mueller matrix measurements

2018 ◽  
Vol 5 (12) ◽  
pp. 181096 ◽  
Author(s):  
Arturo Mendoza-Galván ◽  
Eloy Muñoz-Pineda ◽  
Kenneth Järrendahl ◽  
Hans Arwin
Keyword(s):  
Structural Parameters ◽  
Polarized Light ◽  
Mueller Matrix ◽  
Scarab Beetle ◽  
Nonlinear Regression Analysis ◽  
Dominant Effect ◽  
Left Handed ◽  
Reflected Light ◽  
Cuticle Thickness ◽  
Level Profile

Helicoidal structures of lamellae of nanofibrils constitute the cuticle of some scarab beetles with iridescent metallic-like shine reflecting left-handed polarized light. The spectral and polarization properties of the reflected light depend on the pitch of the helicoidal structures, dispersion of effective refractive indices and thicknesses of layers in the cuticle. By modelling the outer exocuticle of the scarab beetle Cotinis mutabilis as a stack of continuously twisted biaxial slices of transparent materials, we extract optical and structural parameters by nonlinear regression analysis of variable-angle Mueller-matrix spectroscopic data. Inhomogeneities in the beetle cuticle produce depolarization with non-uniformity in cuticle thickness as the dominant effect. The pitch across the cuticle of C . mutabilis decreased with depth in a two-level profile from 380 to 335 nm and from 390 to 361 nm in greenish and reddish specimens, respectively, whereas in a yellowish specimen, the pitch decreased with depth in a three-level profile from 388 to 326 nm.

scholarly journals Analysis of ellipsometric parameters in the reflection of circularly polarized light from a thin anisotropic plate

2021 ◽  
Vol 2094 (2) ◽  
pp. 022071
Author(s):  
V V Yatsyshen
Keyword(s):  
Anisotropic Plate ◽  
Plate Boundary ◽  
Polarized Light ◽  
High Sensitivity ◽  
Incident Radiation ◽  
Angle Of Incidence ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Left Handed ◽  
Reflected Light

Abstract The article presents the results of the analysis of the angular spectra of the ellipsometric parameters of the reflected wave when a circularly polarized light wave is incident on an anisotropic plate. The given dependences show a very high sensitivity of the ellipsometric parameters of the reflected light on the angle of incidence and the angle between the optical axis and the normal to the plate boundary. The energy reflection spectra themselves show much less variability when these parameters change. It should be especially emphasized the nature of the change in the ellipsometric angle Δ, which is responsible for the type of elliptical polarization - when Δ> 0, the polarization is left-handed, and when Δ <0, it is right-handed. It is shown that a thin anisotropic plate at certain angles can serve as a polarization converter of the incident radiation. The ellipsometry parameter ρ characterizes the degree of compression of the ellipse - when ρ = 1, the ellipse is transformed into a circle, and the light is circularly polarized in this case. Thus, a thin anisotropic plate can not only convert left-handed polarization to right-handed, but it can also control the very shape of the polarization ellipse. Such a plate can be used in conjunction with a layered medium, for example, a one-dimensional photonic crystal, to control the polarization of the incident circularly polarized light.

scholarly journals Quantification of Optical Chirality in Cellulose Nanocrystal Films Prepared by Shear-Coating

2021 ◽  
Vol 11 (13) ◽  
pp. 6191
Author(s):  
Olga Rubí Juárez-Rivera ◽  
Reina Araceli Mauricio-Sánchez ◽  
Kenneth Järrendahl ◽  
Hans Arwin ◽  
Arturo Mendoza-Galván
Keyword(s):  
Self Assembly ◽  
Polarized Light ◽  
Mueller Matrix ◽  
Cellulose Nanocrystal ◽  
Free Standing ◽  
Full Characterization ◽  
Glass Substrates ◽  
Left Handed ◽  
Optical Chirality ◽  
Transmission Modes

Evaporation-induced-self-assembly is widely used to produce chiral cellulose nanocrystal (CNC) free-standing films reflecting left-handed polarized light. Research on supported chiral CNC films is rather scarce. The reflection and/or transmission of unpolarized light are the most common optical techniques used to characterize the selective reflection of CNC films whereas the use of techniques to quantify chiral properties is limited. Here, the fabrication of chiral CNC films supported on glass substrates by a shear-coating method, as well as a full characterization of their polarization properties, are reported. Optical chirality is evidenced in films, showing a brilliant blue structural color when viewed through a left-handed polarizer and darkness through a right-handed polarizer. Mueller-matrix data in the reflection and transmission modes are used to quantitatively characterize the structural origin of color in the films. The quantification of the linear and circular birefringence, as well as circular dichroism, is performed by analytical inversion of the Mueller matrix data in the transmission mode and regression analysis using Tellegen constitutive equations. The equivalence of the two methods to quantify the structural chirality in CNC films is demonstrated. The swelling of films in water and kinetics during drying is studied by reflection spectroscopy.

scholarly journals Optically ambidextrous circularly polarized reflection from the chiral cuticle of the scarab beetle Chrysina resplendens

2017 ◽  
Vol 14 (131) ◽  
pp. 20170129 ◽  
Author(s):  
Ewan D. Finlayson ◽  
Luke T. McDonald ◽  
Pete Vukusic
Keyword(s):  
Polarized Light ◽  
Scattering Matrix ◽  
Scarab Beetle ◽  
Optical Behaviour ◽  
Structural Morphology ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Left Handed ◽  
Optical Effects ◽  
Incremental Rotation

The evolution of structural colour mechanisms in biological systems has given rise to many interesting optical effects in animals and plants. The instance of the scarab beetle Chrysina resplendens is particularly distinctive. Its exoskeleton has a bright, golden appearance and reflects both right-handed and left-handed circularly polarized light concurrently. The chiral nanostructure responsible for these properties is a helicoid, in which birefringent dielectric planes are assembled with an incremental rotation. This study correlates details of the beetle's circularly polarized reflectance spectra directly with physical aspects of its structural morphology. Electron micrography is used to identify and measure the physical dimensions of the key constituent components. These include a chiral multilayer configuration comprising two chirped, left-handed helicoids that are separated by a birefringent retarder. A scattering matrix technique is used to simulate the system's optical behaviour in which the roles of each component of the morphological substructure are elucidated by calculation of the fields throughout its depth.

Dalnegroite, Tl5–xPb2x(As,Sb)2l–xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Switzerland

2009 ◽  
Vol 73 (6) ◽  
pp. 1027-1032 ◽  
Author(s):  
F. Nestola ◽  
A. Guastoni ◽  
L. Bindi ◽  
L. Secco
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Concentrations ◽  
Reflected Light ◽  
Mohs Hardness ◽  
The Mean ◽  
The University ◽  
Probable Space

AbstractDalnegroite, ideally Tl4Pb2(As12Sb8)Σ20S34, is a new mineral from Lengenbach, Binntal, Switzerland. It occurs as anhedral to subhedral grains up to 200 μm across, closely associated with realgar, pyrite, Sb-rich seligmanite in a gangue of dolomite. Dalnegroite is opaque with a submetallic lustre and shows a brownish-red streak. It is brittle; the Vickers hardness (VHN25) is 87 kg mm-2(range: 69—101) (Mohs hardness ∼3—3½). In reflected light, dalnegroite is highly bireflectant and weakly pleochroic, from white to a slightly greenish-grey. In cross-polarized light, it is highly anisotropic with bluish to green rotation tints and red internal reflections.According to chemical and X-ray diffraction data, dalnegroite appears to be isotypic with chabournéite, Tl5-xPb2x(Sb,As)21-xS34. It is triclinic, probable space groupP1, witha= 16.217(7) Å,b= 42.544(9) Å,c= 8.557(4) Å, α = 95.72(4)°, β = 90.25(4)°, γ = 96.78(4)°,V= 5832(4) Å3,Z= 4.The nine strongest powder-diffraction lines [d(Å) (I/I0) (hkl)] are: 3.927 (100) (10 0); 3.775 (45) (22); 3.685 (45) (60); 3.620 (50) (440); 3.124 (50) (2); 2.929 (60) (42); 2.850 (70) (42); 2.579 (45) (02); 2.097 (60) (024). The mean of 11 electron microprobe analyses gave elemental concentrations as follows: Pb 10.09(1) wt.%, Tl 20.36(1), Sb 23.95(1), As 21.33(8), S 26.16(8), totalling 101.95 wt.%, corresponding to Tl4.15Pb2.03(As11.86Sb8.20)S34. The new mineral is named for Alberto Dal Negro, Professor in Mineralogy and Crystallography at the University of Padova since 1976.

Phase Detection for Nanometer Scale Metal Film’s Thickness Based on SPR Effect

2011 ◽  
Vol 320 ◽  
pp. 377-381 ◽  
Author(s):  
Jin Dong Xin ◽  
Qing Gang Liu ◽  
Chao Liu ◽  
Ting Ting Li ◽  
Shi Yi Liu
Keyword(s):  
Film Thickness ◽  
Resonance Effect ◽  
Polarized Light ◽  
Nanometer Scale ◽  
Phase Detection ◽  
Surface Plasmon Resonance Effect ◽  
Interference Fringes ◽  
Reflected Light ◽  
Phase Data ◽  
Spr Effect

It is found that the phase position of p-component of reflected light changes with the metal film thickness, while the phase position of s-component almost doesn’t change in the Surface Plasmon Resonance effect. S-polarized light is taken as reference and interferometry is adopted to turn the change of the phase position into the change of interference fringes position in the paper, and the film thickness can be derived from it. The simulation results indicated that, through making use of piecewise quadratic fitting on the phase data, the inaccuracy with the range of film thickness is between 30 and 80 nanometers is not more than 0.33 nm.

Polarized Light Studies of the Cornea

1953 ◽  
Vol 30 (2) ◽  
pp. 164-169
Author(s):  
A. STANWORTH
Keyword(s):  
Intraocular Pressure ◽  
Human Subject ◽  
Reasonable Agreement ◽  
Polarized Light ◽  
Transmitted Light ◽  
Posterior Surface ◽  
Photographic Image ◽  
Reflected Light

A method is described of measuring the birefringence of the intact cornea using light reflected obliquely from its posterior surface. The value obtained (0.0037) is in reasonable agreement with the results obtained by using transmitted light and from corneal sections. The change in birefringence with an increase in intraocular pressure from 10 to 40 mm. Hg is about 7% of this. The change in birefringence was also assessed by changes in the density of the photographic image of the reflected light from the surface, and this affords a possible way in which the intraocular pressure could be measured in the human subject without touching the eye.

Reduction of Reflected Light On Fluorescence Emission for Indocyanine Green

2021 ◽  
Author(s):  
So Yoon Kwon ◽  
Ki-Cheol Yoon ◽  
Kwang Gi Kim
Keyword(s):  
Blood Vessel ◽  
Indocyanine Green ◽  
Blood Vessels ◽  
Light Emitting Diode ◽  
Polarized Light ◽  
Fluorescence Emission ◽  
Light Reflection ◽  
Light Emitting ◽  
Surgical Microscope ◽  
Reflected Light

Abstract Inside the brain tumor, the blood vessels are intricately composed, and the tumors and blood vessels are similar in color. Therefore, when observing tumors and blood vessels with the naked eye or a surgical microscope, it is difficult to distinguish between tumors and blood vessels. Fluorescence staining with indocyanine green (ICG) is performed to distinguish between brain tumors and blood vessels using a surgical microscope. However, when observing the blood circulation state of a tumor or blood vessel through a surgical microscope, light reflection occurs from the camera. In the process of observing the state of the blood vessel, due to the occurrence of light reflection, an obstruction phenomenon in which the observation field is blocked by the blood vessel of the object to be observed occurs. Therefore, it is difficult to diagnose the vascular condition. In this experiment, the 780nm light-emitting diode (LED) was irradiated to the ICG phantom, and then, when the fluorescence expression image was observed, the polarizing filter such as circular polarized light (CPL) filter and linear polarized light (LPL) filter were inserted into the camera and the reflected light was reduced. Therefore, it is possible to reduce the reflected light from the fluorescence expression image by using a polarizing filter, and it is expected to be applicable to surgery and diagnostic fields of cancer such as surgery.

Wood identification of charcoal with 3D-reflected light microscopy

IAWA Journal ◽  
2020 ◽  
Vol 41 (4) ◽  
pp. 478-489 ◽  
Author(s):  
Valentina Zemke ◽  
Volker Haag ◽  
Gerald Koch
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Field Emission ◽  
Polarized Light ◽  
Structural Features ◽  
Light Illumination ◽  
Reflected Light ◽  
Carbonized Wood ◽  
Scanning Electron

Abstract The present study focusses on the application of 3D-reflected light microscopy (3D-RLM) for the wood anatomical identification of charcoal specimens produced from domestic and tropical timbers. This special microscopic technique offers a detailed investigation of anatomical features in charcoal directly compared with the quality of field emission scanning electron microscopy (FESEM). The advantages of using the 3D-RLM technology are that fresh fracture planes of charcoal can be directly observed under the microscope without further preparation or surface treatment. Furthermore, the 3D-technique with integrated polarized light illumination creates high-contrast images of uneven and black charcoal surfaces. Important diagnostic structural features such as septate fibres and intercellular canals can be clearly detected and intervessel pits are directly measured. The comparison of the microscopic analyses reveals that 3D-reflected light microscopy (3D-RLM) provides an effective alternative technique to conventional field emission scanning electron microscopy for the identification of carbonized wood.

scholarly journals Multipole Radiations from Large Gold Nanospheres Excited by Evanescent Wave

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 175
Author(s):  
Jingdong Chen ◽  
Jin Xiang ◽  
Shuai Jiang ◽  
Qiaofeng Dai ◽  
Shaolong Tie ◽  
...  
Keyword(s):  
Evanescent Wave ◽  
Polarized Light ◽  
Electric Quadrupole ◽  
Photonic Devices ◽  
High Order ◽  
Gold Nanospheres ◽  
Reflected Light ◽  
Gold Nanosphere ◽  
Scattering Light ◽  
Plasmon Modes

We proposed the use of the evanescent wave generated in a total internal reflection configuration to excite large gold nanospheres and investigated the radiations of the high-order plasmon modes supported in gold nanospheres. It was revealed that the evanescent wave excitation is equivalent to the excitation by using both the incident and reflected light, offering us the opportunity to control the orientation of the electric field used to excite nanoparticles. In addition, it was found that the scattering light intensity is greatly enhanced and the background noise is considerably suppressed, making it possible to detect the radiations from high-order plasmon modes. Moreover, the influence of the mirror images on the scattering induced by a metal substrate is eliminated as compared with the surface plasmon polariton excitation. By exciting a gold nanosphere with s-polarized light and detecting the scattering light with a p-polarized analyzer, we were able to reveal the radiation from the electric quadrupole mode of the gold nanosphere in both the spatial and the frequency domains. Our findings are important for characterizing the radiations from the high-order modes of large nanoparticles and useful for designing nanoscale photonic devices.

scholarly journals Polarization Controlled Dual Functional Reflective Planar Metalens in Near Infrared Regime

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 389 ◽  
Author(s):  
Yuhui Zhang ◽  
Bowei Yang ◽  
Zhiying Liu ◽  
Yuegang Fu
Keyword(s):  
Near Infrared ◽  
Polarized Light ◽  
New Method ◽  
Dual Functional ◽  
Light Manipulation ◽  
Reflected Light ◽  
Polarization States ◽  
Dual Functions

The metalens has been a hotspot in scientific communications in recent years. The polarization-controlled functional metalens is appealing in metalens investigation. We propose a metalens with dual functions that are controlled by polarization states. In the first design, when applied with x- and y-polarized light, two focal spots with different focal lengths are acquired, respectively. The proposed metalens performs well when illuminated with adjacent wavelengths. In the second design, the reflected light is focused when applied with x-polarized light, and when applied with y-polarized light, the reflected light is split into two oblique paths. We believe that the results will provide a new method in light manipulation.

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