Optical polarization

About: Optical polarization is a research topic. Over the lifetime, 13992 publications have been published within this topic receiving 244284 citations.

Ellipse rotation studies in laser host materials

Abstract: Using a TEM 00q near Gaussian mode ruby laser system we report the first experimental measurements of intensity induced changes of optical polarization (ellipse rotation) in a cubic crystalline medium, YAG, for which we obtain the nonlinear susceptibilities \chi_{3}^{1221} (- \omega, \omega, \omega, -\omega) = 6.34 \times 10^{-15} ESU and \frac{1}{2} (\chi_{3}^{1111} + \chi_{3}^{1221} - 2\chi_{3}^{1212}) = 7.18 \times 10^{-15} ESU, accurate to better than ±7 percent relative to \chi_{3}^{1221} (- \omega,\omega,\omega, -\omega) for liquid CS 2 . These values are compared with further results obtained for fused quartz and two laser glasses. Moreover, by time resolving the ellipse rotation data we demonstrate the capability to plot ellipse rotation versus input power on a single laser shot, thus increasing the practical feasibility of the technique and introducing the possibility of resolving transient contributions to the measurement.

Record heavy Asian dust in Beijing in 2002: Observations and model analysis of recent events

Abstract: [1] A record heavy Yellow Sand event was observed on 20 March in Beijing. This event was unusual because the wind speed was low and the dust concentration was extremely high at the dust front. Observations with a polarization lidar, an optical particle counter, and a high-volume sampler were performed throughout the event in Beijing. The visibility derived from the lidar data was 650 m, and the total suspended particle concentration was 11 mg/m3 at the peak. Chemical transport model analysis revealed that the main part of the dust originated in the Mongolian border area near Ejinaqi. This dust event severely affected Korea and northern Japan. Continuous lidar observations in Beijing, Nagasaki and Tsukuba revealed that the frequency of dust events in 2001 and 2002 was similar in Beijing but much higher in 2002 in Nagasaki and Tsukuba. The model showed dust was transported to the east more frequently in 2002 and the difference is probably related to the smaller perturbation of the westerly jet. This indicates that a slight change in climate can cause a large difference in dust phenomena in the northwestern Pacific region.

The Imaging X-ray Polarimetry Explorer (IXPE)

Abstract: The Imaging X-ray Polarimetry Explorer (IXPE) is an exciting international collaboration for a scientific mission that dramatically brings together the unique talents of the partners to expand observation space by simultaneously adding polarization measurements to the array of source properties currently measured (energy, time, and location). IXPE uniquely brings to the table polarimetric imaging. IXPE will thus open new dimensions for understanding how X-ray emission is produced in astrophysical objects, especially systems under extreme physical conditions-such as neutron stars and black holes. Polarization singularly probes physical anisotropies-ordered magnetic fields, aspheric matter distributions, or general relativistic coupling to black-hole spin-that are not otherwise measurable. Hence, IXPE complements all other investigations in high-energy astrophysics by adding important and relatively unexplored information to the parameter space for studying cosmic X-ray sources and processes, as well as for using extreme astrophysical environments as laboratories for fundamental physics.

Dual-band negative index metamaterial: double negative at 813 nm and single negative at 772 nm.

Abstract: This work is concerned with the experimental demonstration of a dual-band negative index metamaterial. The sample is double negative (showing both a negative effective permeability and a negative effective permittivity) for linearly polarized light with a wavelength between 799 and 818 nm, and the real part of its refractive index is approximately −1.0 at 813 nm. The ratio of −Re(n)/Im(n) is close to 1.3 at 813 nm. For an orthogonal polarization, the same sample also exhibits a negative refractive index in the visible (at 772 nm). The spectroscopic measurements of the material are in good agreement with the results obtained from a finite-element electromagnetic solver for the actual geometry of the fabricated sample at both polarizations.

Wavelength-Selective Switches for ROADM Applications

Abstract: The trends, architecture, and performance of wavelength-selective switches (WSS) are analyzed in the context of their application to reconfigurable optical add/drop multiplexer (ROADM)-based optical networks. The resulting analyses define the requirements for the latest generation of ROADM systems and provide insight into the critical specifications of this technology. In addition, the current trends for WSS technology are reviewed in the context of synergies with the strengths of different switching technologies.