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 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 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 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 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.

Depolarization of Light by Mono-Dispersed Air Bubbles Coated With Carbonaceous Particles

2003 ◽  
Author(s):  
Basil T. Wong ◽  
Rodolphe Vaillon ◽  
M. Pinar Mengu¨c¸
Keyword(s):  
Polarized Light ◽  
Incident Radiation ◽  
Air Bubbles ◽  
Carbonaceous Particles ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Cylindrical System ◽  
Coal Particles ◽  
Linearly Polarized ◽  
Depolarization Of Light

In this paper, the potential use of polarized light for characterization of mono-dispersed air bubbles coated with carbonaceous particles is investigated using a vector Monte Carlo approach. The medium is assumed to be water, loaded with highly-forward scattering ash and coal particles, as well as absorbing and scattering air bubbles coated with a thin carbonaceous (soot) layer. A polarized laser beam is assumed to impinge normally on a cylindrical system at the circumferential surface, and the scattered signals are assumed to be collected within the same plane. The scattering matrix for the entire medium is constructed based on the Fresnel equations. Examination of the absorbing and multiple-scattering results show that if circularly polarized light is used, the bubble size, the bubble separation, as well as the thickness of carbonaceous layer around bubbles can be determined if careful experiments are conducted. It is shown that circularly polarized light is a better choice than the linearly polarized incident radiation for the present diagnosis objectives.

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
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