Advances in Polarization Engineering

Polarization plays an important role in many optical systems and device. This includes devices designed to advantageously use polarization, like liquid crystal displays, and optical systems that measure polarization to obtain information not otherwise available, like instruments found in many modern telescopes. Polarization also needs to be considered in some systems where it is not a primary aspect of the design, like image formation in very high numerical aperture objective lenses. This manuscript discusses three optical engineering projects where accurate polarization analysis or testing was required. Chapter one discusses a case where the need for polarization engineering arises from extreme optical requirements. Exoplanet direct imaging requires extremely high contrast, so any possible phase errors need to be considered. This includes the effects of form birefringence, which had previously not been measured over a large diameter mirror. Chapter one presents the first measurements of form birefringence over a large diameter telescope mirror. Measurements of the 3.75-meter, spherical mirror, coated by vacuum deposition of aluminum, indicate low levels of retardance and diattenuation that vary over the face of the mirror. The retardance and diattenuation had maximum values of about 2x10-3 radians and 0.025% respectively. Initial modeling by Davis J., et al. shows that this level of form birefringence could be impactful in direct imaging systems. The chapter discusses the design of the metrology system used to perform the measurements. The polarization engineering in chapter 2 relates to a remote sensing instrument that detects polarization to provide information in addition to its spectral reflectance measuring capabilities. Chapter two covers the design and testing of the second-generation polarization state generator used for the calibration and testing of Jet Propulsion Laboratory’s (JPL) air-based, multispectral polarimetric imager (AirMSPI). The chapter focuses on the requirements of a polarization standard. The first-generation instrument is analyzed carefully and the lessons learned are applied to improving the second. The updated version has been successfully used for AirMSPI calibration prior to multiple airborne science campaigns. The third chapter discusses the analysis and modification of a nominally non-polarizing optical sub-system that has polarization design requirements. This highlights important polarization issues that occur is systems containing a large number of surfaces. The issues with the systems polarization performance are identified. A method to improve the polarization performance that can be implemented without any additional calculations is demonstrated. The system is then modified to improve the polarization performance while maintaining other important optical properties. Finally, the manufacturability of the modified design is considered

OCULAR VERGENCE RESPONSE OVER ANAGLYPHIC STEREOSCOPIC VIDEOS

The effect of anaglyphic stereographic stimuli on ocular vergence response is examined. An experiment is performed comparing ocular vergence response induced by anaglyphic stereographic display versus standard monoscopic display. Two visualization tools, synchronized three-dimensional scanpath playback and real-time dynamic heatmap generation, are developed and used to subjectively support the quantitative analysis of ocular disparity. The results of a one-way ANOVA indicate that there is a highly significant effect of anaglyphic stereoscopic display on ocular vergence for a majority of subjects although consistency of vergence response is difficult to predict

Improved Detection of Gold Nanoparticle Labels for Paper-based Analytics

Point-of-care diagnostic devices are well-suited, and typically designed, for remote and/or resource-limited environments. The obvious application is for healthcare in the developing world; however, other additional important uses exist, including for security (biothreat agent detection) and human health and research during future manned deep space exploration missions. The objective of this thesis was to develop, and experimentally validate, techniques for improved quantified detection of labels used in lateral flow assays. Limits of detection were characterized for: (a) optical approaches, i.e., unaided eye, mobile electronic device camera images and microscope images with image analysis software developed through this thesis, and (b) a conductance based approach with direct measurement of electrical impedance in the detection region using hardware and software that were developed. Analysis of camera images from mobile electronic devices enables simultaneous detection of many targets on a multiplexed assay. Additionally, a peripheral device was designed which was intended to provide conductimetric analysis capabilities to mobile electronic devices. The detection limit of gold nanoparticles for the unaided eye was determined at a concentration of (3.98 ± 0.40)×10-11 M; mobile electronic device image analysis, microscope image analysis, and the conductance based approach showed improvements by approximately a half to a third, an order of magnitude, and three orders of magnitude, respectively

Diversification of the Caenorhabditis heat shock response by Helitron transposable elements.

Heat Shock Factor 1 (HSF-1) is a key regulator of the heat shock response (HSR). Upon heat shock, HSF-1 binds well-conserved motifs, called Heat Shock Elements (HSEs), and drives expression of genes important for cellular protection during this stress. Remarkably, we found that substantial numbers of HSEs in multiple Caenorhabditis species reside within Helitrons, a type of DNA transposon. Consistent with Helitron-embedded HSEs being functional, upon heat shock they display increased HSF-1 and RNA polymerase II occupancy and up-regulation of nearby genes in C. elegans. Interestingly, we found that different genes appear to be incorporated into the HSR by species-specific Helitron insertions in C. elegans and C. briggsae and by strain-specific insertions among different wild isolates of C. elegans. Our studies uncover previously unidentified targets of HSF-1 and show that Helitron insertions are responsible for rewiring and diversifying the Caenorhabditis HSR

Coherent Detector for Near-Angle Scattering and Polarization Characterization of Telescope Mirror Coatings

A report discusses the difficulty of measuring scattering properties of coated mirrors extremely close to the specular reflection peak. A prototype Optical Hetero dyne Near-angle Scatterometer (OHNS) was developed. Light from a long-coherence-length (>150 m) 532-nm laser is split into two arms. Acousto-optic modulators frequency shift the sample and reference beams, establishing a fixed beat frequency between the beams. The sample beam is directed at very high f/# onto a mirror sample, and the point spread function (PSF) formed after the mirror sample is scanned with a pinhole. This light is recombined by a non-polarizing beam splitter and measured through heterodyne detection with a spectrum analyzer. Polarizers control the illuminated and analyzed polarization states, allowing the polarization dependent scatter to be measured. The bidirectional reflective or scattering distribution function is normally measured through use of a scattering goniometer instrument. The instrumental beam width (collection angle span) over which the scatterometer responds is typically many degrees. The OHNS enables measurement at angles as small as the first Airy disk diameter

Method and Apparatus for Measuring Near-Angle Scattering of Mirror Coatings

Disclosed herein is a method of determining the near angle scattering of a sample reflective surface comprising the steps of: a) splitting a beam of light having a coherence length of greater than or equal to about 2 meters into a sample beam and a reference beam; b) frequency shifting both the sample beam and the reference beam to produce a fixed beat frequency between the sample beam and the reference beam; c) directing the sample beam through a focusing lens and onto the sample reflective surface, d) reflecting the sample beam from the sample reflective surface through a detection restriction disposed on a movable stage; e) recombining the sample beam with the reference beam to form a recombined beam, followed by f) directing the recombined beam to a detector and performing heterodyne analysis on the recombined beam to measure the near-angle scattering of the sample reflective surface, wherein the position of the detection restriction relative to the sample beam is varied to occlude at least a portion of the sample beam to measure the near-angle scattering of the sample reflective surface. An apparatus according to the above method is also disclosed

Alloy Design Workbench-Surface Modeling Package Developed

NASA Glenn Research Center's Computational Materials Group has integrated a graphical user interface with in-house-developed surface modeling capabilities, with the goal of using computationally efficient atomistic simulations to aid the development of advanced aerospace materials, through the modeling of alloy surfaces, surface alloys, and segregation. The software is also ideal for modeling nanomaterials, since surface and interfacial effects can dominate material behavior and properties at this level. Through the combination of an accurate atomistic surface modeling methodology and an efficient computational engine, it is now possible to directly model these types of surface phenomenon and metallic nanostructures without a supercomputer. Fulfilling a High Operating Temperature Propulsion Components (HOTPC) project level-I milestone, a graphical user interface was created for a suite of quantum approximate atomistic materials modeling Fortran programs developed at Glenn. The resulting "Alloy Design Workbench-Surface Modeling Package" (ADW-SMP) is the combination of proven quantum approximate Bozzolo-Ferrante-Smith (BFS) algorithms (refs. 1 and 2) with a productivity-enhancing graphical front end. Written in the portable, platform independent Java programming language, the graphical user interface calls on extensively tested Fortran programs running in the background for the detailed computational tasks. Designed to run on desktop computers, the package has been deployed on PC, Mac, and SGI computer systems. The graphical user interface integrates two modes of computational materials exploration. One mode uses Monte Carlo simulations to determine lowest energy equilibrium configurations. The second approach is an interactive "what if" comparison of atomic configuration energies, designed to provide real-time insight into the underlying drivers of alloying processes

Prospectus, May 10, 1983

s fashions; Lack of experience causes motorcycle accidents; Park District kicks off summer season; Park Districts begin new Life campaign; Summer brings quality; Graduation 1983 -- Tears and Laughter!; When were The Good Old Days?; Gayle Wright: Parkland\u27s early morning fisherman; Classified; D.J.\u27s honored; Return of the Jedi worth standing in line for; Blue Thunder: the ultimate weapon; MTD announces Roadeo winnerhttps://spark.parkland.edu/prospectus_1983/1016/thumbnail.jp

Increasing Adipocyte Lipoprotein Lipase Improves Glucose Metabolism in High Fat Diet-Induced Obesity

Lipid accumulation in liver and skeletal muscle contributes to co-morbidities associated with diabetes and obesity. We made a transgenic mouse in which the adiponectin (Adipoq) promoter drives expression of lipoprotein lipase (LPL) in adipocytes to potentially increase adipose tissue lipid storage. These mice (Adipoq-LPL) have improved glucose and insulin tolerance as well as increased energy expenditure when challenged with a high fat diet (HFD). To identify the mechanism(s) involved, we determined whether the Adipoq-LPL mice diverted dietary lipid to adipose tissue to reduce peripheral lipotoxicity, but we found no evidence for this. Instead, characterization of the adipose tissue of the male mice after HFD challenge revealed that the mRNA levels of peroxisome proliferator-activated receptor-γ (PPARγ) and a number of PPARγ-regulated genes were higher in the epididymal fat pads of Adipoq-LPL mice than control mice. This included adiponectin, whose mRNA levels were increased, leading to increased adiponectin serum levels in the Adipoq-LPL mice. In many respects, the adipose phenotype of these animals resembles thiazolidinedione treatment except for one important difference, the Adipoq-LPL mice did not gain more fat mass on HFD than control mice and did not have increased expression of genes in adipose such as glycerol kinase, which are induced by high affinity PPAR agonists. Rather, there was selective induction of PPARγ-regulated genes such as adiponectin in the adipose of the Adipoq-LPL mice, suggesting that increasing adipose tissue LPL improves glucose metabolism in diet-induced obesity by improving the adipose tissue phenotype. Adipoq-LPL mice also have increased energy expenditure