Practical design issues for snapshot Mueller matrix spectropolarimetry

We discuss practical design constraints for snapshot Mueller matrix spectropolarimeters, and reveal a robustness problem with existing designs. By carefully choosing the ratios of thicknesses between the four thick retarders used in these systems, we can avoid requiring extremely tight tolerances, though at a cost in overall bandwidth. We provide example designs and quantify the robustness-resolution tradeoff.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]

Dynamic calibration of a channeled spectropolarimeter for extended temperature stability

Channeled Spectropolarimeters (CHSP) are compact optical instruments that have potential for making precise polarization measurements without any moving parts. While most spectropolarimeters use rotating elements to make measurements, CHSPs use mechanically fixed thick retarders to modulate the Stokes vector onto the spectrum of light. In realistic applications, CHSPs must have calibration algorithms that give stable measurements in a variety of environmental conditions. Previous researchers developed a self-calibration algorithm that uses redundant channel information to compensate temperature-induced phase fluctuations in real-time without any additional reference measurements. In this paper we discuss the stability of the self-calibration technique. We identify a mathematical ambiguity in the algorithm that limits the range of temperatures over which the algorithm is stable. For a 60 lambda:120 lambda channeled spectropolarimeter with quartz retarders, the stable temperature range is only 27 degrees C and is not suitable for many applications outside of the laboratory. We propose and demonstrate a modified algorithm that uses the slope of the phase to remove the mathematical ambiguity and extend the temperature range of the system. The demonstration shows stable operation over a 41 degrees C temperature range and shows promise for increasing stability over a temperature range suitable for extreme terrestrial conditions.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]

Stroboscopic oblique-incidence interferometer for motion visualization of stator of ultrasonic motor.

AbstractThis paper describes a motion-visualization technique for an ultrasonic motor (USM) by using a stroboscopic oblique-incidence interferometer. Characteristics of USM depend on a vibration mode of a stator which is one of main component of USM. Though there are some visualization techniques of its vibrated mode, it is difficult to visualization. Because the surface of the stator is rough for a light. For visualization such a surface, we focused on an oblique-incidence interferometer. The interferometer is well suited to analyze the rough surface because a scattering at the rough surface is reduced by using an oblique-incidence light. Furthermore, for detecting a vibrated surface, a pulsed light synchronized with stator was used as light source. We have succeeded to detect a periodically movement of fringe patterns of the vibrated stator

Wave description of geometric phase

Since Pancharatnam's 1956 discovery of optical geometric phase, and Berry's 1984 discovery of geometric phase in quantum systems, researchers analyzing geometric phase have focused almost exclusively on algebraic approaches using the Jones calculus, or on spherical trigonometry approaches using the Poincar\'e sphere. The abstracted mathematics of the former, and the abstracted geometry of the latter, obscure the physical mechanism that generates geometric phase. We show that optical geometric phase derives entirely from the superposition of waves and the resulting shift in the location of the wave maximum. This wave-based model provides a way to visualize how geometric phase arises from relationships between waves, and from the transformations induced by optical elements. We also derive the relationship between the geometric phase of a wave by itself and the phase exhibited by an interferogram, and provide the conditions under which the two match one another

Detection Sensitivity of Iron-Foil Corrosion Sensor in Simulated Concrete Solution

This examined the performance of the iron-foil sensor in concrete and its relationship with the amount of chloride in the solution simulating concrete. The corrosion sensor reacted at a chloride ion concentration of 500 ppm. From the results, it was inferred that the sensor has a high sensitivity. Furthermore, to evaluate the performance of the sensor, it was built a wireless system using radiofrequency identification (RFID), embed it into an actual concrete structure, and subsequently initiate observation

calc_covariances.py

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20th International Symposium on Optomechatronic Technology

This book presents peer-reviewed articles from the 20th International Symposium on Optomechatronic Technologies (ISOT 2019), held in Goa, India. The symposium brought together students, researchers, professionals, and academicians in the field of optomechatronics and related areas on a common platform conducive to academic interaction with business professionals

High Precision Stokes Polarimetry for Scattering Light using Wide Dynamic Range Intensity Detector

This paper proposes a Stokes polarimetry for scattering light from a sample surface. To achieve a high accuracy measurement two approaches of an intensity detector and analysis algorism of a Stokes parameter were proposed. The dynamic range of this detector can achieve up to 1010 by combination of change of neutral-density (ND) filters having different density and photon counting units. Stokes parameters can be measured by dual rotating of a retarder and an analyzer. The algorism of dual rotating polarimeter can be calibrated small linear diattenuation and linear retardance error of the retarder. This system can measured Stokes parameters from −20° to 70° of its scattering angle. It is possible to measure Stokes parameters of scattering of dust and scratch of optical device with high precision. This paper shows accuracy of this system, checking the polarization change of scattering angle and influence of beam size