Optical polarization

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

Ray tracing with polarization parameters

Abstract: Incorporating polarization parameters into the lighting model can enhance the physical realism of images rendered with a ray tracer. Polarization effects can be important in certain scenes, and the difference in rendering even simple scenes with and without proper treatment of polarization can be striking. All light waves possess a state of polarization, which changes almost every time light reflects off a material surface. A single reflection partially polarizes and may even completely polarize previously unpolarized light. Polarization influences the rendering of a scene because the reflected radiant intensity depends largely on the incident light waves's polarization state. E. Wolf's (1959) coherence matrix formalism of polarization has been incorporated into the Torrance-Sparrow reflectance model. This combination allows elegant quantitative derivations of the altered polarization state of light upon reflection in a ray tracer. Comparisons of identical scenes rendered with a conventional ray tracer and the ray tracer presented incorporating a polarization model show that the present method renders specular interobject reflections more accurately with respect to reflected radiance and color. >

Performance of 1-THz-bandwidth, two-dimensional smoothing by spectral dispersion and polarization smoothing of high-power, solid-state laser beams

Abstract: Laser beam smoothing achieved with 1-THz-bandwidth, two-dimensional smoothing by spectral dispersion and polarization smoothing on the 60-beam, 30-kJ, 351-nm OMEGA laser system is reported. These beam-smoothing techniques are directly applicable to direct-drive ignition target designs for the 192-beam, 1.8-MJ, 351-nm National Ignition Facility. Equivalent-target-plane images for constant-intensity laser pulses of varying duration were used to determine the smoothing. The properties of the phase plates, frequency modulators, and birefringent wedges were simulated and found to be in good agreement with the measurements.

New implementation of symbolic substitution logic.

Abstract: Symbolic substitution is a spatial logic for digital optical computers that utilizes the specific advantages of optical signal processing. Previous implementations used the optical intensity for coding the binary values. In this implementation we are using polarization for coding, and we show how a complete recognition–substitution processor can be implemented. The advantages of this type of coding are: better utilization of the device area, an equal distribution of intensity, and symmetry between the two logic states.

Are there reliable methods to estimate the nuclear orientation of Seyfert galaxies

Abstract: Together with accretion and evolution, orientation is one of the three main drivers in the grand unification of active galactic nuclei (AGNs). Being unresolved, determining the true inclination of those powerful sources is always difficult and indirect, yet it remains a vital clue to apprehend the numerous, panchromatic and complex spectroscopic features we detect. There have only been 100 inclinations derived so far; in this context, can we be sure that we measure the true orientation of AGNs? To answer this question, four methods to estimate the nuclear inclination of AGNs are investigated and compared to inclination-dependent observables (hydrogen column density, Balmer linewidth, optical polarization and flux ratios within the infrared and relative to X-rays). Among these orientation indicators, the method developed by Fisher, Crenshaw, Kraemer, and others, mapping and modelling the radial velocities of the [O III] emission region in AGNs, is the most successful. The [O III]-mapping technique shows highly statistically significant correlations at >95 per cent confidence level for rejecting the null hypothesis for all the test cases. Such results confirm that the unified model is correct at a scale ranging from kiloparsec to a fraction of a parsec. However, at a radial distance less than 0.01 pc from the central black hole, warps and misalignments may change this picture.