scholarly journals Broad-Band Transmission Characteristics of Polarizations in Foggy Environments

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 342 ◽  
Author(s):  
Tianwei Hu ◽  
Fei Shen ◽  
Kaipeng Wang ◽  
Kai Guo ◽  
Xiao Liu ◽  
...  
Keyword(s):  
Broad Band ◽  
Polarized Light ◽  
Mean Value ◽  
Degree Of Polarization ◽  
Transmission Characteristics ◽  
Circularly Polarized Light ◽  
The Difference ◽  
Index Ratio ◽  
Scattering Index ◽  
Scattering Systems

Based on the Monte Carlo (MC) algorithm, we simulate the evolutions of different types of the polarized lights in the broad-band range from visible to infrared in foggy environments. Here, we have constructed two scattering systems to simulate the transmission characteristics of the polarized lights: (1) A monodisperse system based on five types of particles with the sizes of 0.5, 1.0, 2.5, 4, and 5 µm, respectively; (2) a polydisperse system based on scattering particles with a mean value (size) of 2.0 μm. Our simulation results show that linearly polarized light (LPL) and circularly polarized light (CPL) exhibit different advantages in different wavelengths and different scattering systems. The polarization maintenances (PM) of the degree of circular polarizations (DoCPs) are better than those of the degree of linear polarizations (DoLPs) for most incident wavelengths. CPL is not superior to LPL in the strong-absorption wavelengths of 3.0µm, 6.0µm, and long infrared. Here, when the wavelength is closer to the particle sizes in a system, the influence on propagating polarizations will be more obvious. However, the difference in the degree of polarization (DoP) between the resulting CPL and LPL is positive at these points, which means the penetrating ability of CPL is superior to that of LPL in these scattering systems. We have also simulated the extinction efficiency Qext and the scattering index ratio Qratio as functions of both wavelength and particle size for analyzing polarization’s transmission characteristics. Our work paves the way of selecting the optimal incident wavelengths and polarizations for concrete scattering systems.

scholarly journals Polarized proton beams from laser-induced plasmas

2019 ◽  
Vol 7 ◽  
Author(s):  
Anna Hützen ◽  
Johannes Thomas ◽  
Jürgen Böker ◽  
Ralf Engels ◽  
Ralf Gebel ◽  
...  
Keyword(s):  
Laser System ◽  
Polarized Light ◽  
Particle Beam ◽  
Degree Of Polarization ◽  
Acceleration Process ◽  
Simulation Code ◽  
Experimental Realization ◽  
Circularly Polarized Light ◽  
Spin Effects ◽  
Polarized Proton

We report on the concept of an innovative source to produce polarized proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven plasma accelerator. Spin effects have been implemented into the particle-in-cell (PIC) simulation code VLPL (Virtual Laser Plasma Lab) to make theoretical predictions about the behavior of proton spins in laser-induced plasmas. Simulations of spin-polarized targets show that the polarization is conserved during the acceleration process. For the experimental realization, a polarized HCl gas-jet target is under construction using the fundamental wavelength of a Nd:YAG laser system to align the HCl bonds and simultaneously circularly polarized light of the fifth harmonic to photo-dissociate, yielding nuclear polarized H atoms. Subsequently, their degree of polarization is measured with a Lamb-shift polarimeter. The final experiments, aiming at the first observation of a polarized particle beam from laser-generated plasmas, will be carried out at the 10 PW laser system SULF at SIOM, Shanghai.

scholarly journals Casimir force induced by electromagnetic wave polarization in Kerr, Gödel and Bianchi–I spacetimes

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Felipe A. Asenjo ◽  
Sergio A. Hojman
Keyword(s):  
Electromagnetic Waves ◽  
Casimir Force ◽  
Polarized Light ◽  
Casimir Forces ◽  
Circularly Polarized Light ◽  
Bianchi I ◽  
Phase Velocities ◽  
Light Waves ◽  
Waves Propagation ◽  
The Difference

AbstractElectromagnetic waves propagation on either rotating or anisotropic spacetime backgrounds (such as Kerr and Gödel metrics, or Bianchi–I metric) produce a reduction of the magnitude of Casimir forces between plates. These curved spacetimes behave as chiral or birefringent materials producing dispersion of electromagnetic waves, in such a way that right– and left–circularly polarized light waves propagate with different phase velocities. Results are explicitly calculated for discussed cases. The difference on the wavevectors of the two polarized electromagnetic waves produces an abatement of a Casimir force which depends on the interaction between the polarization of electromagnetic waves and the properties of the spacetime.

Optical Pumping and Optical Detection of Spin-Polarized Electrons in a Conduction Band

1971 ◽  
Vol 49 (14) ◽  
pp. 1850-1860 ◽  
Author(s):  
R. R. Parsons
Keyword(s):  
Magnetic Field ◽  
Conduction Band ◽  
Spin Polarization ◽  
Optical Pumping ◽  
Polarized Light ◽  
Degree Of Polarization ◽  
Polarized Electrons ◽  
Excitation Light ◽  
Circularly Polarized Light ◽  
Spin Polarized

Spin-polarized electrons are created in the conduction band of p-type GaSb by excitation with σ+ or σ− circularly polarized light. The degree of polarization of the photoluminescence is used to measure the optically pumped spin polarization. The measurements as a function of transverse magnetic field yield the spin-relaxation time and the lifetime of the photocreated electrons. The degree of polarization oscillates as a function of the photon energy of the excitation light. This effect is associated with mechanisms of rapid energy loss involving optical and acoustical phonons. The optical pumping is studied as a function of temperature in the range 3.5 °K ≤ T ≤ 11 °K. A maximum spin polarization [Formula: see text] is obtained at [Formula: see text]. The efficiency of the optical pumping is significantly increased with the application of a weak longitudinal magnetic field.

scholarly journals Enantioselective fragmentation of an achiral molecule in a strong laser field

2019 ◽  
Vol 5 (3) ◽  
pp. eaau7923 ◽  
Author(s):  
K. Fehre ◽  
S. Eckart ◽  
M. Kunitski ◽  
M. Pitzer ◽  
S. Zeller ◽  
...  
Keyword(s):  
Single Molecule ◽  
Light Propagation ◽  
Polarized Light ◽  
Strong Laser Field ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Single Molecule Level ◽  
The Difference ◽  
Living Nature ◽  
Chiral Species

Chirality is omnipresent in living nature. On the single molecule level, the response of a chiral species to a chiral probe depends on their respective handedness. A prominent example is the difference in the interaction of a chiral molecule with left or right circularly polarized light. In the present study, we show by Coulomb explosion imaging that circularly polarized light can also induce a chiral fragmentation of a planar and thus achiral molecule. The observed enantiomer strongly depends on the orientation of the molecule with respect to the light propagation direction and the helicity of the ionizing light. This finding might trigger new approaches to improve laser-driven enantioselective chemical synthesis.

Electric-field-induced differential scattering of right and left circularly polarized light

1975 ◽  
Vol 345 (1642) ◽  
pp. 365-377 ◽  
Keyword(s):  
Electric Field ◽  
Optical Activity ◽  
Electromagnetic Waves ◽  
Polarized Light ◽  
Static Electric Field ◽  
Circularly Polarized Light ◽  
Active Systems ◽  
Circularly Polarized ◽  
Dipolar Molecules ◽  
The Difference

The differential scattering of right and left circularly polarized light is a manifestation of optical activity. Both naturally optically active systems and fluids in a magnetic field parallel to the direction of propagation exhibit differential scattering. Although there is no electric analogue of Faraday’s effect, a static electric field applied to a fluid perpendicular to the direction of propagation induces a difference in the scattered intensities of right and left circularly polarized light. The difference is linear in the field strength. It is determined by the effect of the field on the polarizabilities producing optical activity and is present in all matter, including monatomic gases. The classical theory of the scattering of electromagnetic waves is used in a formulation of the general theory of light scattering in an electric field. Results are given for some particular symmetries, including spherical, tetrahedral and dipolar molecules, and estimates of the magnitude of the effect are made.

scholarly journals Measuring circular phase-dichroism of chiral metasurface

Nanophotonics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 909-920 ◽  
Author(s):  
Ranran Zhang ◽  
Qiuling Zhao ◽  
Xia Wang ◽  
Wensheng Gao ◽  
Jensen Li ◽  
...  
Keyword(s):  
Incident Light ◽  
Polarized Light ◽  
Visible Range ◽  
Chiral Media ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Reflection Phase ◽  
Full Wave ◽  
Potential Applications ◽  
The Difference

AbstractThe ability of chiral media to differentiate circularly polarized light is conventionally characterized by circular dichroism (CD) which is based on the difference in the absorption of the incident light for different polarizations. Thus, CD probes the bulk properties of chiral media. Here, we introduce a new approach termed as circular phase-dichroism that is based on the surface properties and is defined as the difference of the reflection phase for different circularly polarized incident lights in characterizing chiral media. As a demonstration, we measure the reflection phase from planar chiral sawtooth metasurface for circularly polarized light in the visible range using a simple Fabry Perot interference technique. The measured circular phase-dichroism is also crosschecked by conventional CD measurement of the transmitted light and by full-wave simulations. Our results demonstrate the potential applications of circular phase-dichroism in sensing and metasurface characterizations.

Hameka theory of optical rotation

1968 ◽  
Vol 46 (4) ◽  
pp. 599-604 ◽  
Author(s):  
D. A. Hutchinson
Keyword(s):  
Scattering Amplitudes ◽  
Optical Rotation ◽  
Polarized Light ◽  
Electric Quadrupole ◽  
Refractive Indices ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Alternative Approach ◽  
Left And Right ◽  
The Difference

sRosenfeld's formula, for off-resonance optical rotation, is derived by an alternative approach. The scattering amplitudes are determined for the scattering of right circularly polarized light and left circularly polarized light by a molecule. The calculation is carried out to the order of approximation which includes electric quadrupole and magnetic dipole terms. From the real parts of the forward scattering amplitudes the corresponding indices of refraction are determined for left and right circularly polarized light. Rosenfeld's formula then follows from the difference between the two refractive indices.

Optical Pumping of Spin-Polarized Conduction Electrons and Inelastic Scattering by Neutral Acceptors

1973 ◽  
Vol 51 (7) ◽  
pp. 718-723 ◽  
Author(s):  
R. R. Parsons
Keyword(s):  
Inelastic Scattering ◽  
Spin Polarization ◽  
Optical Pumping ◽  
Polarized Light ◽  
Energy Relaxation ◽  
Degree Of Polarization ◽  
Conduction Band Edge ◽  
Circularly Polarized Light ◽  
Conduction Electrons ◽  
Spin Polarized

The energy relaxation mechanisms of conduction electrons in p-type GaSb at 1.9 °K are investigated by an optical pumping technique. Spin-polarized electrons are excited across the forbidden band gap with circularly polarized light. The number of photocreated electrons is obtained from the intensity of the photoluminescence; and the spin polarization from the degree of polarization of the photoluminescence. The experiment shows that the number of electrons and the spin polarization at the conduction band edge depend on the initial energy of the electrons and on the number of neutral acceptors. An explanation of the results is given in terms of two processes of energy relaxation for conduction electrons: (i) the emission of longitudinal optical phonons, and (ii) inelastic scattering by neutral acceptors.

Differential polarization imaging of sickled cells

1988 ◽  
Vol 46 ◽  
pp. 62-63
Author(s):  
Marcos F. Maestre
Keyword(s):  
Optical Properties ◽  
Theoretical Approach ◽  
Polarized Light ◽  
Polarization Microscopy ◽  
Spectroscopic Techniques ◽  
Polarization Imaging ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Microscopic Scale ◽  
Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

Reliability of a Single β-Thromboglobulin Measurement in a Diabetic Population : Importance of PGE1 in Anticoagulant Mixture

1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner
Keyword(s):  
In Vitro Release ◽  
Mean Value ◽  
Reliable Estimate ◽  
Diabetic Patients ◽  
Single Measurement ◽  
Diabetic Population ◽  
The Difference ◽  
Vitro Release

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.

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