Polarizing beam splitter cube for circularly and elliptically polarized light

A method of designing an arbitrary polarizing beam splitter (PBS) cube using multiple layers of thin-film liquid crystal polymer is demonstrated. This methodology utilizes cholesteric phase liquid crystal polymer (Ch-LCP) to transmit one handedness of elliptically polarized light and reflect the orthogonal state when unpolarized light is incident. Using additional nematic liquid crystal polymer layers, the polarization state for the transmitted and reflected light can be controlled and output to any two orthogonal states represented on the Poincarte sphere. Two cubes are designed, fabricated, tested, and compared with theory. One cube is constructed with a single layer of Ch-LCP, and another cube is constructed with a layer of Ch-LCP and an additional nematic liquid crystal polymer layer.National Science Foundation (NSF) [1607358]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Multi-wavelength quantitative polarization and phase microscope

We introduce a snapshot multi-wavelength quantitative polarization and phase microscope (MQPPM) for measuring spectral dependent quantitative polarization and phase information. The system uniquely integrates a polarized light microscope and a snap-shot quantitative phase microscope in a single system, utilizing a novel full-Stokes camera operating in the red, green, and blue (RGB) spectrum. The linear retardance and fast axis orientation of a birefringent sample can be measured simultaneously in the visible spectra. Both theoretical analysis and experiments have been performed to demonstrate the capability of the proposed microscope. Data from liquid crystal and different biological samples are presented. We believe that MQPPM will be a useful tool in measuring quantitative polarization and phase information of live cells. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing AgreementNational Science Foundation (NSF) [1455630, 1607358]; National Institutes of Health (NIH) [S10OD018061]; TRIF Space Exploration & Optical Sciences (SEOS) of University of ArizonaOpen access journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Broadband Full-Stokes Polarimetry

Broadband full-Stokes polarimetry can capture polarization images over a wide wavelength spectrum, for example visible spectrum (380nm to 740nm), near infrared spectrum (780nm to 2500nm) or both. In this dissertation, we discuss several topics on designing a broadband full-Stokes polarimeter and then demonstrate two polarimeters experimentally. We first study two theoretical problems, the first one is the optimized sensor design for color polarization imaging. This includes three parts, the tiling of N types of optical filters on a 2D rectangular grid that minimizes interpolation error, the choice of color filters and the choice of analyzers, to minimize the influence from noise on color polarization reconstruction. The second problem is how to design achromatic polarization elements. This is the key to enable broadband polarization measurement. We analyze a special case that uses two linear retarders of the same birefringent material and one linear polarizer to achieve an achromatic elliptical polarizer/analyzer. We also address several concerns on choosing the right achromatic analyzer design for polarimeters. Two types of RGB full-Stokes imaging polarimeter are constructed, calibrated and tested. The first one uses a beam splitter and two linear-Stokes cameras to form a division-of-amplitude polarimeter. The second type applies a patterned micro-retarder on a pixelated wire-grid micro-polarizer to form a division-of-focal plane polarimeter. Both can capture the intensity, color and polarization of an optical field in a single shot

Visualization 1.mp4

RGB full-Stokes video of a rotating polarization wheel is taken by an RGB full-Stokes camera. Videos of four Stokes parameters and DoLP & DoCP at each color channel are included. The polarization wheel is covered with linear polarizers in the outer circle and circular polarizers in the inner circle. In the image, we see that the outer circle has large linear polarization while inner circle has large circular polarization

Design, fabrication and testing of achromatic elliptical polarizer

A method of designing achromatic elliptical polarizers using a combination of multiple birefringent waveplates is demonstrated. This approach has a simple geometric interpretation and simplifies the problem of designing an achromatic elliptical polarizer to find overlapping arcs on the Poincare sphere. The technique is applied to the design of achromatic elliptical polarizers for a broadband division-of-focal-plane full-Stokes imaging polarimeter for visible wavelength band (lambda = 450nm to 650nm). An achromatic elliptical polarizer sample with a two-layer retarder is fabricated using liquid crystal polymer. The performance of the polarizer sample is measured and compared with the theoretical calculation. For comparison, a superachromatic polarizer design (lambda = 400nm to 1 mu m) is also presented by using three-layer and four-layer retarder configurations. (C) 2017 Optical Society of AmericaArizona Technology Research Infrastructure Fund (TRIF); National Science Foundation (NSF) [1607358]Open Access Journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Observation of elliptically polarized light from total internal reflection in bubbles

Bubbles are ubiquitous in the natural environment, where different substances and phases of the same substance forms globules due to differences in pressure and surface tension. Total internal reflection occurs at the interface of a bubble, where light travels from the higher refractive index material outside a bubble to the lower index material inside a bubble at appropriate angles of incidence, which can lead to a phase shift in the reflected light. Linearly polarized skylight can be converted to elliptically polarized light with efficiency up to 53% by single scattering from the water-air interface. Total internal reflection from air bubble in water is one of the few sources of elliptical polarization in the natural world. Stationary and dynamic scenes of air bubbles in water in both indoor and outdoor settings are studied using an imaging polarimeter. Our results are important for studies in fluid dynamics, remote sensing, and polarimetry.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Snapshot multi-wavelength interference microscope

A snapshot multi-wavelength interference microscope is proposed for high-speed measurement of large vertical range discontinuous microstructures and surface roughness. A polarization CMOS camera with a linear micro-polarizer array and Bayer filter accomplishes snapshot multi-wavelength phase-shifting measurement. Four interferograms with /2 phase shift are captured at each wavelength for phase measurement, the 2 ambiguities are removed by using two or three wavelengths.</p

Design, fabrication and testing of achromatic elliptical polarizer

A method of designing achromatic elliptical polarizers using a combination of multiple birefringent waveplates is demonstrated. This approach has a simple geometric interpretation and simplifies the problem of designing an achromatic elliptical polarizer to find overlapping arcs on the Poincare sphere. The technique is applied to the design of achromatic elliptical polarizers for a broadband division-of-focal-plane full-Stokes imaging polarimeter for visible wavelength band (lambda = 450nm to 650nm). An achromatic elliptical polarizer sample with a two-layer retarder is fabricated using liquid crystal polymer. The performance of the polarizer sample is measured and compared with the theoretical calculation. For comparison, a superachromatic polarizer design (lambda = 400nm to 1 mu m) is also presented by using three-layer and four-layer retarder configurations. (C) 2017 Optical Society of AmericaArizona Technology Research Infrastructure Fund (TRIF); National Science Foundation (NSF) [1607358]Open Access Journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]