Polarized Light Transmission Research Articles

The model and characteristics of polarized light transmission applicable to polydispersity particle underwater environment

The information about the polarization of underwater objects can be affected by the absorption and scattering of water particles, making it challenging to detect underwater targets accurately. Therefore, it is essential to analyze the characteristics of polarization transmission in water. Traditional Monte Carlo simulations have yet to effectively treat particle size in water, which is unsuitable for the underwater environment of polydispersity particles with significant particle size differences. In this paper, a new simulation model using a Monte Carlo method with random sampling fitting phase functions is proposed, which makes the transmission characteristics of water particles more in line with the actual probability model of complex water bodies. The experimental results demonstrate that the proposed Monte Carlo method produces polarization closer to experimental results. The larger the particle size of water suspensions, the greater change of the polarization degree of polarized light. The polarization-maintaining characteristics of circularly polarized light are better than those of linearly polarized light, providing data support for the transmission and detection of underwater light.

3‐3: Anamorphic‐XR: Imaging Waveguide Technology for Efficient and Wide Field‐of‐View Near‐Eye Display

A near‐eye display technology, Anamorphic‐XRTM, incorporating imaging waveguides is described. Developed for multiple applications since 2011, unique light manipulation capabilities and highly compact form factors are achievable. Catadioptric anamorphic optics and polarisation management are used to sidestep limitations of conventional VR lens and AR waveguide displays, enhancing performance and manufacturability. Simulations and measurements indicate an achievable specification of 90º field‐of‐view at 60ppd; >2000 nits/lumen; 80% polarised light transmission; and >15mm eyebox at 18mm eye relief from a <4mm thick waveguide. A Hybrid Immersive Display is proposed, combining an anamorphic waveguide with a conventional VR display.

Characterization of multi-wavelength polarized light transmission in the real sea spray environment

Sea spray particles are a type of non-uniform, non-spherical, non-isotropic, and complex medium, and the study of the transmission characteristics of polarized light in a real sea spray environment can provide reference values in many fields, such as polarization imaging, marine target detection, and LiDAR, which can make up for the vacancy of polarized light transmission in a complex sea spray environment. In this paper, a real sea fog test is carried out in the Qingdao Sea area of China in the horizontal/oblique direction, and a platform for generating and detecting polarized light with multiple tilt angles is constructed by using the active test method, which realizes the test scheme for the characteristics of energy change and polarization state change in the linearly polarized light and circularly polarized light at different visibility levels in sea fog environments. The results show that it is more difficult to deflect the circularly polarized light than linearly polarized light at the same sea spray visibility level. With the increase in the tilt angle, a decrease in the polarization is observed. The polarization of the near-infrared light is always larger than that of the visible light, which indicates that the circularly polarized light has better polarization preservation than the linearly polarized light and the polarization preservation of the near-infrared light is better than that of the visible light.

Polarized light transmission characteristics in a smoky ellipsoidal particle medium.

True natural environments are more complex, and light travels through non-spherical particle media, which can affect the transmission of light. The medium environment of non-spherical particles is more common than that of spherical particles, and some studies have shown that there are differences between spherical and non-spherical particles in polarized light transmission. Therefore, the use of spherical particles instead of non-spherical particles will result in great error. In view of this feature, this paper samples the scattering angle based on the Monte Carlo method, and then constructs a simulation model of a random sampling fitting phase function suitable for ellipsoidal particles. In this study, yeast spheroids and Ganoderma lucidum spores were prepared. The effects of different polarization states and optical thicknesses on the transmission of polarized light at three wavelengths were investigated using ellipsoidal particles with a ratio of 1.5 transverse to vertical axes. The results show that when the concentration of the medium environment increases, the polarized lights of different states all show obvious depolarization, but circularly polarized light has better polarization-preserving characteristics than linearly polarized light, and polarized light with larger wavelengths also shows more stable optical properties. When yeast and Ganoderma lucidum spores were used as the transport medium, the degree of polarization of polarized light had the same trend. However, the equal volume radius of yeast particles is smaller than that of Ganoderma lucidum spores, so when the laser is in the yeast particle medium, the polarization-maintaining property of polarized light is superior. This study provides an effective reference for the variation of polarized light transmission in an atmospheric transmission environment with heavy smoke.

Polarization Transmission of Visible Light in Inhomogeneous Sea Fog Particle Environment

Sea fog is a weather phenomenon suspended in the ocean-atmosphere boundary layer. This phenomenon makes the horizontal visibility of the sea atmosphere less than 1 km. Sea fog reduces sea surface visibility. Moreover, the inhomogeneous sea fog particles in the transmission channel result in the absorption and scattering of photons, which seriously affect the performance of optical detection instruments. Polarization imaging detection can solve this problem. However, the evolution law of transmission characteristics between polarized light and inhomogeneous sea fog particles remains unclear. Therefore, we use the equivalent analysis method to improve Monte Carlo, and finally construct the inhomogeneous particle scattering model. The influence of wavelength and relative humidity on DOP (Degree of Polarization) was calculated by the model. The simulated sea fog was created using brine with a preset concentration, and then established an experimental system close to the actual sea fog environment. Indoor polarized light transmission experiments verified the inhomogeneous particle scattering model. Results showed that the accuracy of the inhomogeneous particle scattering model can reach more than 75%. In the visible band, the DOP decreases with the wavelength increase. DOP450 (Degree of Polarization at 450nm wavelength) is approximately 3–10% higher than DOP532, and DOP532 is approximately 5% higher than DOP671. The relative humidity increases from 45% to 85%, and DOP increases by 10–15%. Therefore, in the visible band, the wavelength and relative humidity are inversely proportional to DOP.

Fabrication of biaxial polarization-maintaining optical fiber with ultra-low bending-dependent polarization extinction ratio deterioration

Different applications, including interferometers, gyroscopes, and frequency combs, require a single polarized light transmission by maintaining this property against the environmental perturbation. As a new type of polarization-maintaining (PM) fiber, a biaxial PM fiber was fabricated over 30 dB of high polarization extinction ratio (PER) values among two orthogonal axes over a fiber length of 110 m. The PM fiber was manufactured with a combination of an elliptical core and Panda-type geometries. The PER values were demonstrated to be preserved at harsh temperature conditions from −55 °C to +85 °C. The bending loss measurements indicate the biaxial PM fiber has ultra-low bending dependent PER deterioration (<0.5 %) at various bending diameters from 12 mm to 5 mm. The biaxial PM property was also confirmed by the group beat length measurements and found to be less than 1.5 mm at 1550 nm. The optical time-domain reflectometer (OTDR) measurements show that the optical loss of the biaxial PM fiber was below 1.5 dB/km over 3kmlength. The mode-field diameter (MFD) and the numerical aperture (NA) values were also reported along two polarized axes. This novel PM fiber offers a single solution for the elliptical and Panda-type PM fibers utilized for integrated fiber-based sensors and instruments.

Linearly Polarized Light Transmission from a Pair of Cycloidal Diffractive Waveplates

Linearly Polarized Light Transmission from a Pair of Cycloidal Diffractive Waveplates

Broad Palettes of Polarizing Structural Color Filter Based on Subwavelength Metallic Nanograting

We propose a new polarizing color filter (CF) design based on one-dimensional subwavelength grating. The proposed CF only allows the transverse magnetic (TM)–polarized light transmission with the desired colors, and broad palettes can be acquired by only tuning the geometric parameter of period. Specifically, the transmittances of 74.7%, 87.9%, and 84.5% are obtained for the blue, green, and red polarizing filters. Furthermore, the corresponding full width at half-maximum is less than 58 nm for the designed tricolor filters. Theoretical analyses demonstrate that cavity modes and guide mode resonant contribute to the enhanced optical TM polarized light transmission.

火星沙尘环境中的偏振光传输特性仿真

火星沙尘环境中的偏振光传输特性仿真

Polarized light through polycrystalline vaterite helicoids.

Vaterite helicoids [W. Jiang et al., Nat. Commun., 2017, 8, 15066] are chiral, polycrystalline suprastructures grown in the presence of the amino acids, aspartic (Asp) or glutamic (Glu) acid, that are abundant in proteins regulating biomineralization. These complex objects are composed of hexagonal vaterite nanocrystals assembled as curved-edge platelets that form chiral ensembles. The sense stacked platelets is correlated with the stereochemistry of the amino acid additive: l-Asp gives counterclockwise architectures while d-Asp gives the clockwise enantiomorphs. As new layers stack, platelets become progressively inclined with respect to the substrate suface. The growth and structure of vaterite helicoids was originally evidenced by electron microscopy and atomic force microscopy. Here, we develop an optical model for describing polarized light transmission through helicoids as measured by Mueller matrix polarimetry. The close agreement between experimental measurements and simulation confirms that the propellor-like organization of inclined platelets creates optically active structures determined by growth additive stereochemistry. The microscopy employed demonstrates the information that can be obtained by complete polarimetry using a camera as a light detector, a technique that could be applied profitably to all manner of complex structures organized from anisotropic particles.

Broad visible spectral subwavelength polarizer with high extinction ratio using hyperbolic metamaterial.

A subwavelength polarizer with an extinction ratio greater than 50 dB in the visible region (exceeding 80 dB in the 500 to 800 nm wavelength region) is presented that uses hyperbolic metamaterial decorated on each side with a subwavelength grating. The approach is based on the spatial frequency filtering characteristics of the hyperbolic metamaterial with its alternating metal-dielectric nano-film, which enables squeezing of bulk plasmon polaritons to support transverse magnetic polarized light transmission in the high spatial wavevector modes while suppressing other polarization mode waves over the broad visible spectrum. The proposed method exhibits a more realizable fabrication process than that used for a subwavelength polarizer based on high-aspect-ratio grating for broad spectrum and high-extinction-ratio performance. The subwavelength polarizer in this work is potential for the high-sensitivity polarimetric imaging.

Submicron object recognition in nematic liquid crystals

ABSTRACTWe present large-scale lattice Monte Carlo simulations of nematic ordering in the vicinity of submicron objects — colloids or viruses — of different shapes (spherical, cubical or icosahedral) immersed in a nematic liquid crystal. We simulate polarized light transmission patterns for the various particles and find that they are distinguishable, suggesting that they might be useful for object shape recognition or, in case of viruses, for diagnostic purposes.

Polarized light transmission in ferrofluids loaded with carbon nanotubes in the presence of a uniform magnetic field

Magneto-optic phenomena in ferrofluids have been shown to be related to the formation of chain structures, due to the arrangement of the ferromagnetic particles, induced by an applied magnetic field. In this work, the effects on transmission of polarized light due to anisotropic effects induced by an external magnetic field in ferrofluids with carbon nanotubes are studied. The time response of the system presents two well defined stages, in the first one, which is very short, the fluid behaves as a polarizer. In contrast in the second stage, the effects of light transmission dominate. In this stage the transmitted light intensity grows with time and after a long time reaches a constant stable value. It is shown that these phenomena depend on the carbon nanotubes concentration as well as on the strength of the applied magnetic field. Using a simple model that considers a chain-like structure formation, it is possible to determine the rate of agglomeration of the formed structures and the attenuation coefficient of the transmitted light. The formation of nanostructures leads to variation in the transmitted light, depending on the polarization of the incident light. These magnetic nanostructures can find numerous applications in nanotechnology, optical devices and medicine.

SU‐E‐T‐37: An Optical Investigation Into the Polarization and Scattering Effects Underlying the Artifacts of Radiochromic Film Dosimetry with Commercial Flatbed Scanners

Purpose:This study aims to investigate the optical properties of radiochromic EBT3 films on exposure to polarized incident light.Methods:An optical table setup was used to investigate the properties of exposed and unexposed EBT3 films. The films were placed with their long side horizontally and illuminated with polarized incident white light. The polarization of light with the electrical vector pointing vertically is referred to as 0°, accordingly horizontal orientation corresponds to 90°. The light transmission was measured depending on the polarization angle of the incident light and the polarization of a polarizer in front of the detector. Secondly, the scattering properties of exposed and unexposed films were measured by placing a plane convex lens behind the films and a screen in its focal plane. Thereby, the distribution of the scattering angles appears as an intensity map on the screen. The distributions of scattering angles caused by EBT3 films and by neutral density filters were compared.Results:EBT3 films show a strong dependence of the light transmission on the polarization of the incident light. With both polarizers parallel, a peak transmission was found at 90° orientation of the polarizers. With the rear polarizer at right angles with the front polarizer, peak transmissions were found at front polarizer orientations 45° and 135°. The scattering appears to be anisotropic with a preference direction parallel to the long side of the film. The portion of scattered light and the half value scattering angle both increase with the dose on the film.Conclusion:EBT3 films show dose dependent changes in polarized light transmission and anisotropic light scattering. These effects impair the light absorption measurements on exposed films performed with commercial flatbed scanners and are causing the well‐known artifacts of radiochromic film dosimetry with flatbed scanners, the “orientation effect” and the “parabola effect”.

Polarization-Sensitive Linear Plasmonic Nanostructures via Colloidal Lithography with Uniaxial Colloidal Arrays

The ability of metallic nanostructures to support surface plasmon excitations is widely exploited nowadays for developing new technologies and applications in many fields, like communications, medicine or environment. It is known that the plasmonic response of a nanostructure is strongly dependent on its size and shape, and thus a fine control of these features is required for developing applications. In this paper uniaxial colloidal crystal arrays are prepared by convective self-assembly on DVD surfaces. These are then used as template/mask for metal film deposition, in order to obtain two original kinds of metallic nanostructures with controllable morphology: (i) linear arrays of metal half-shells (LAMHSs) and (ii) arrays of periodically serrated plasmonic strips (PSPSs). Angle-resolved optical transmittance measurements reveal the presence of several surface plasmon resonances, while polarized light transmission demonstrates the anisotropic plasmonic response of both LAMHSs and PSPSs. FDTD simulations support the experimental observations and help in the assignments of observed plasmon modes. The proposed linear metallic nanostructures can prove useful for the design of plasmonic components.

Effect of 10-T magnetic fields on structural colors in guanine crystals of fish scales

This work reports the magnetically modulated structural colors in the chromatophore of goldfish scales under static magnetic fields up to 10 T. A fiber optic system for spectroscopy measurements and a CCD microscope were set in the horizontal bore of a 10-T superconducting magnet. One leaf of a fish scale was set in a glass chamber, exposed to visible light from its side direction, and then static magnetic fields were applied perpendicular to the surface of the scale. In addition, an optical fiber for spectroscopy was directed perpendicular to the surface. During the magnetic field sweep-up, the aggregate of guanine thin plates partially showed a rapid light quenching under 0.26 to 2 T; however, most of the thin plates continued to scatter the side-light and showed changing iridescence, which was displayed individually by each guanine plate. For example, an aggregate in the chromatophore exhibited a dynamic change in structural color from white-green to dark blue when the magnetic fields changed from 2 to 10 T. The spectrum profile, which was obtained by the fiber optic system, confirmed the image color changes under magnetic field exposure. Also, a linearly polarized light transmission was measured on fish scales by utilizing an optical polarizer and analyzer. The transmitted polarized light intensities increased in the range of 500–550 nm compared to the intensity at 700 nm during the magnetic field sweep-up. These results indicate that the multi-lamella structure of nano-mirror plates in guanine hexagonal micro-plates exhibit diamagnetically modulated structure changes, and its light interference is affected by strong magnetic fields.

Magneto-optical cellular chip model for intracellular orientational-dynamic-activity detection

In the present study, a magneto-optical cellular chip model (MoCCM) was developed to detect intracellular dynamics in macromolecules by using magneto-optical effects. For the purpose of cell-measurement under strong static magnetic fields of up to 10 T, we constructed a cellular chip model, which was a thin glass plate with a well for a cell culture. A cell line of osteoblast MC3T3-E1 was incubated in the glass well, and the well, 0.3 mm in depth, was sealed by a cover glass when the MoCCM was set in a fiber optic system. An initial intensity change of the polarized light transmission, which dispersed perpendicular to the cell’s attaching surface, was collected for 10 to 60 min, and then magnetic fields were applied parallel and perpendicular to the surface and light direction, respectively. The magnetic birefringence signals that originated from the magnetic orientation of intracellular molecules such as cytoskeletons apparently appeared when the magnetic fields were constant at 10 T. A statistical analysis with 15 experiments confirmed that the cellular components under 10 T magnetic fields caused a stronger alignment, which was transferred into polarizing light intensity that increased more than the case before exposure. Cellular conditions such as generation and cell density affected the magnetic birefringence signals.

Anatomical analysis of the light transmission through a single subwavelength metal slit by the FDTD method

Transverse-magnetic (TM) polarized light transmission through a single subwavelength metal slit is re-examined with finite-difference time-domain (FDTD) simulations. In contrast to previous studies, we derive an anatomical view of the electromagnetic field distribution in different cross-sections and emphasize the generation of a field coupling mode in the slit. Numerical modeling reveals that both peak and dip transmissions are features of the field interference in the slit. The slit width and depth are mainly responsible for establishing the amplitude and phase, respectively, of the coupled mode. Moreover, it is found that the output energy dispensation between the radiative and surface components is actually determined by the slit width. Analysis of the physical properties of the slit, including the coupled mode structure in the transverse plane, the effective refractive index and Ohmic absorption losses, provides new insights into the light transmission processes.

High Polaried Transmission Effects for Double-Layer Metallic Grating Films on GaN Substrate

Highly polarized light transmission from GaN based light emitting diode is proposed using a double-layer metallic grating film and a dielectric transition layer. TM mode transmission and the polarized extinction ratio (ER) are calculated using commercial software, based on a full vector implementation of Rigorous Coupled Wave Analysis (RCWA) algorithm. Such a thin-film double-layer grating with subwavelength metallic stripes are designed and simulated by perfect parameters of period, thickness and filling factor for achieving good polarization properties. It is found that TM transmission and ER are almost stable and flat under different slit arrays of the double-layer grating. The polarized structure shows larger width of incident wavelength with a transition layer of a low refractive index than that of a high refractive index, but higher TM transmission and ER can be obtained for low refractive index transition layer. Flat sensitivity and high transmission of the TM mode on the double-layer metal grating thickness have been achieved. Up to 100nm range of the grating height can be employed to achieve TM transmission more than 92% while ER&gt; 20dB. The results provide guidance in designing, optimizing and fabricating the integrated GaN-based and polarized photonic devices.

Transmission of polarized light in skeletal muscle

Experiments were conducted to study polarized light transmission in fresh bovine skeletal muscle of varying thicknesses. Two-dimensional polarization-sensitive transmission images were acquired and analyzed using a numerical parametric fitting algorithm. The total transmittance intensity and degree-of-polarization were calculated for both central ballistic and surrounding scattering regions. Full Mueller matrix images were derived from the raw polarization images and the polar decomposition algorithm was applied to extract polarization parameters. The results suggest that polarized light propagation through skeletal muscle is affected by strong birefringence, diattenuation, multiple scattering induced depolarization and the sarcomere diffraction effect.