scholarly journals Circularly polarized light modulated supramolecular self-assembly for an azobenzene-based chiral gel

RSC Advances ◽  
2019 ◽  
Vol 9 (18) ◽  
pp. 10360-10363 ◽  
Author(s):  
Kenan Shao ◽  
Ziyu Lv ◽  
Yuting Xiong ◽  
Guodong Li ◽  
Dongdong Wang ◽  
...  
Keyword(s):  
Traditional Knowledge ◽  
Self Assembly ◽  
Polarized Light ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Left Handed

An unconventional supramolecular self-assembly triggered by left-handed circularly polarized light breaks the traditional knowledge of azobenzene photoisomerization.

scholarly journals Circularly Polarized Light Detection by Chiral Photonic Cellulose Nanocrystal with ZnO Photoconductive Layer in Ultraviolet Region

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3098
Author(s):  
Boyu Zhang ◽  
Sixiang Zhao ◽  
Yingying Yu ◽  
Ming Li ◽  
Liancheng Zhao ◽  
...  
Keyword(s):  
Self Assembly ◽  
Polarization State ◽  
Polarized Light ◽  
Cellulose Nanocrystal ◽  
Ultraviolet Region ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Left Handed ◽  
Chiral Nematic ◽  
Wide Range

Circularly polarized light (CPL) detection and polarization state recognition are required for a wide range of applications. Conventional polarization detection with optical components causes difficulties for miniaturization and integration. An effective design strategy is proposed for direct CPL detection with chiral material. Here, we realized direct CPL detection based on the combination of chiral photonic cellulose nanocrystal (CNC) and ultraviolet-sensitive ZnO photoconductive material. The CNC layer deposited by evaporation-induced self-assembly established the left-handed chiral nematic structure with a photonic bandgap (PBG) to recognize left-handed CPL (LCPL) and right-handed CPL (RCPL) at specific wavelengths. The PBG of CNC layer has been modulated by the adjustment of chiral nematic pitch to match the semiconductor bandgap of ZnO film in ultraviolet region. The photocurrents under RCPL and LCPL are 2.23 × 10−6 A and 1.77 × 10−6 A respectively and the anisotropy factor Δgpc of 0.23 is acquired for the CPL detection based on the chiral photonic CNC. This design provides a new approach to the detection of CPL polarization state with competitive performance.

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 An orbital energy flow and a spin flow at the tight focus

2021 ◽  
Vol 45 (4) ◽  
pp. 520-524
Author(s):  
S.S. Stafeev
Keyword(s):  
Energy Flow ◽  
Optical Axis ◽  
Polarized Light ◽  
Orbital Energy ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Left Hand ◽  
Left Handed ◽  
Sharp Focus ◽  
Positive Projection

We have shown that a reverse energy flow (negative projection of the Poynting vector onto the optical axis) at the sharp focus of an optical vortex with topological charge 2 and left-hand circular polarization arises because the axial spin flow has a negative projection onto the optical axis and is greater in magnitude than positive projection onto the optical axis of the orbital energy flow (canonical energy flow). Also, using the Richards-Wolf formulas, it is shown that when focusing a left-handed circularly polarized light, in the region of the on-axis reverse energy flow, the light is right-handed circularly polarized.

scholarly journals Circularly polarized reflection from the scarab beetle Chalcothea smaragdina : light scattering by a dual photonic structure

2017 ◽  
Vol 7 (4) ◽  
pp. 20160129 ◽  
Author(s):  
Luke T. McDonald ◽  
Ewan D. Finlayson ◽  
Bodo D. Wilts ◽  
Pete Vukusic
Keyword(s):  
Cholesteric Liquid Crystal ◽  
Polarized Light ◽  
Optical Scattering ◽  
Stratified Medium ◽  
Selective Reflection ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Electromagnetic Simulations ◽  
Left Handed ◽  
Colour Appearance

Helicoidal architectures comprising various polysaccharides, such as chitin and cellulose, have been reported in biological systems. In some cases, these architectures exhibit stunning optical properties analogous to ordered cholesteric liquid crystal phases. In this work, we characterize the circularly polarized reflectance and optical scattering from the cuticle of the beetle Chalcothea smaragdina (Coleoptera: Scarabaeidae: Cetoniinae) using optical experiments, simulations and structural analysis. The selective reflection of left-handed circularly polarized light is attributed to a Bouligand-type helicoidal morphology within the beetle's exocuticle. Using electron microscopy to inform electromagnetic simulations of this anisotropic stratified medium, the inextricable connection between the colour appearance of C. smaragdina and the periodicity of its helicoidal rotation is shown. A close agreement between the model and the measured reflectance spectra is obtained. In addition, the elytral surface of C. smaragdina possesses a blazed diffraction grating-like surface structure, which affects the diffuse appearance of the beetle's reflected colour, and therefore potentially enhances crypsis among the dense foliage of its rainforest habitat.

scholarly journals High numerical aperture metalens to generate an energy backflow

2020 ◽  
Vol 44 (5) ◽  
pp. 691-698
Author(s):  
V.V. Kotlyar ◽  
S.S. Stafeev ◽  
L. O'Faolain ◽  
M.V. Kotlyar
Keyword(s):  
Focal Length ◽  
Ion Beam ◽  
Near Field ◽  
Fdtd Method ◽  
Numerical Aperture ◽  
Polarized Light ◽  
Optical Microscope ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Left Handed

Using electronic beam lithography and reactive ion beam etching, a metalens is manufactured in a thin layer of amorphous silicon of a 130-nm depth, a 30-µm diameter, and a 633-nm focal length (equal to the illumination wavelength). The metalens is composed of 16 sectored subwavelength binary gratings with a 220-nm period. The uniqueness of this metalens is that when illuminated by left-handed circularly polarized light, it is capable of generating a left-handed circularly polarized vortex beam with a topological charge of 2, generating a second-order cylindrical vector beam when illuminated by linearly polarized light. Both for linear and circular incident polarization, an energy backflow is found to be generated in the vicinity of the tight focus. Transverse intensity distributions measured with a scanning near-field optical microscope near the focus of the metalens are in qualitative agreement with the intensity distributions calculated by the FDTD method. This confirms that a backward energy flow takes place at the focus of the metalens. A metalens generating an energy backflow near its focus is fabricated and characterized for the first time.

scholarly journals Predominantly left-handed circular polarization in comets: Does it indicate L-enantiomeric excess in cometary organics?

2008 ◽  
Vol 4 (S251) ◽  
pp. 311-312 ◽  
Author(s):  
V. Rosenbush ◽  
N. Kiselev ◽  
L. Kolokolova
Keyword(s):  
Light Scattering ◽  
Circular Polarization ◽  
Enantiomeric Excess ◽  
Polarized Light ◽  
Optically Active ◽  
Active Materials ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Cometary Dust ◽  
Left Handed

AbstractPolarimetric observations demonstrated that all comets with significant values of circular polarization show predominantly left–handed circularly polarized light. We discuss the presence of homochiral organics in cometary materials as a source of the observed circular polarization. We have studied the effect of chirality on light–scattering properties of cometary dust considering particles that possess optical activity. Our investigations show that the cometary dust may include optically active materials which can be prebiological homochiral organics.

Light reflection by the cuticle ofC. aurigansscarabs: a biological broadband reflector of left handed circularly polarized light

2014 ◽  
Vol 16 (8) ◽  
pp. 082001 ◽  
Author(s):  
E Libby ◽  
D E Azofeifa ◽  
M Hernández-Jiménez ◽  
C Barboza-Aguilar ◽  
A Solís ◽  
...  
Keyword(s):  
Polarized Light ◽  
Light Reflection ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Left Handed

scholarly journals Direct detection of circular polarized light in helical 1D perovskite-based photodiode

2020 ◽  
Vol 6 (46) ◽  
pp. eabd3274
Author(s):  
A. Ishii ◽  
T. Miyasaka
Keyword(s):  
Direct Detection ◽  
Polarized Light ◽  
Organic Cations ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
One Dimensional ◽  
Left Handed ◽  
Plasmonic Metamaterials ◽  
Halide Perovskites ◽  
Lead Halide

Detection of circularly polarized light (CPL) has a high potential for development of various optical technologies. Conventional photodetectors require optical polarizers on the device to detect polarized light, and this causes substantial losses of sensitivity and resolution in light detection. Here, we report direct CPL detection by a photodiode using a helical one-dimensional (1D) structure of lead halide perovskites composed of naphthylethylamine-based chiral organic cations. The 1D structure with face-sharing (PbI6)4− octahedral chains whose helicity is largely affected by chiral cations shows intense circular dichroism (CD) signals over 3000 mdeg at 395 nm with the highly anisotropy factor (gCD) of 0.04. This high CD enables photocurrent detection with effective discrimination between left-handed and right-handed CPLs. The CPL detector based on this 1D perovskite achieved the highest polarization discrimination ratio of 25.4, which largely surpasses the direct detecting CPL devices (<4) using chiral plasmonic metamaterials and organic materials.

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.

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