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A strong electromagnetic field polarizes the vacuum and in the presence of an electric field creates pairs of a charged particle and its anti-particle. Magnetars, highly magnetized neutron stars with magnetic field comparable to or greater…

High Energy Astrophysical Phenomena · Physics 2021-12-07 Chul Min Kim , Sang Pyo Kim

Currently, a number of experiments are searching for vacuum magnetic birefringence and dichroism, i.e. for dispersive and absorptive features in the propagation of polarized light along a transverse magnetic field in vacuum. In this note we…

High Energy Physics - Phenomenology · Physics 2009-07-09 Markus Ahlers , Joerg Jaeckel , Andreas Ringwald

We have built and tested a 3.5 m high-finesse Fabry-Perot prototype inteferometer with a precision ellipsometer for the QED test and axion search (Q & A) experiment. We use X-pendulum-double-pendulum suspension designs and automatic control…

Instrumentation and Detectors · Physics 2009-11-10 Jeah-Sheng Wu , Wei-Tou Ni , Sheng-Jui Chen

A polarimetric model for the power delay spectrum for inroom communication is proposed. The proposed model describes the gradual depolarization of the signal with delay. The model is based on the theory of room electromagnetics,…

Signal Processing · Electrical Eng. & Systems 2022-02-16 Troels Pedersen , Ramoni Adeogun

The geometric phase is usually treated as a quantity modulo 2\pi, a convention carried over from early work on the subject. The results of a series of optical interference experiments involving polarization of light, done by the present…

Optics · Physics 2015-06-26 Rajendra Bhandari

We present high precision measurements of polarization rotations in the frequency range from 0.1 to 2.5 THz using a polarization modulation technique. A motorized stage rotates a polarizer at ~80 Hz, and the resulting modulation of the…

Optics · Physics 2017-07-26 C. M. Morris , R. Valdés Aguilar , A. V. Stier , N. P. Armitage

The three axis magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric…

Instrumentation and Detectors · Physics 2016-09-21 Swarupananda Pradhan

Considering the spatially separated polarization radiation and Faraday rotation regions to simulate complex interstellar media, we study synchrotron polarization gradient techniques' measurement capabilities. We explore how to trace the…

High Energy Astrophysical Phenomena · Physics 2021-07-14 Ru-Yue Wang , Jian-Fu Zhang , Alex Lazarian , Hua-Ping Xiao , Fu-Yuan Xiang

We developed a polarization modulation unit (PMU) to rotate a waveplate continuously in order to observe solar magnetic fields by spectropolarimetry. The non-uniformity of the PMU rotation may cause errors in the measurement of the degree…

Instrumentation and Methods for Astrophysics · Physics 2015-09-25 Shin-nosuke Ishikawa , Toshifumi Shimizu , Ryouhei Kano , Takamasa Bando , Ryohko Ishikawa , Gabriel Giono , Saku Tsuneta , Satoshi Nakayama , Takao Tajima

In undergraduate optics courses, diffraction gratings are studied extensively, generally within the scalar approximation. When the vector nature of light is taken into account, so-called polarization diffraction gratings have been proposed,…

Optics · Physics 2026-03-13 Massimo Santarsiero , J. C. G. de Sande , Gemma Piquero

A new technique based on superposition of two speckle patterns is proposed and demonstrated for controlled modulation of the spatial polarization distribution of the resultant speckle. It is demonstrated both theoretically and…

Optics · Physics 2021-11-15 Abhijit Roy , Rakesh K. Singh , Maruthi M. Brundavanam

The Q & A experiment, first proposed and started in 1994, provides a feasible way of exploring the quantum vacuum through the detection of vacuum birefringence effect generated by QED loop diagram and the detection of the polarization…

Instrumentation and Detectors · Physics 2007-05-23 Hsien-Hao Mei , Sheng-Jui Chen , Wei-Tou Ni

We investigate theoretically the effects of vacuum-induced coherence (VIC) on magneto-optical rotation (MOR). We carry out a model study to show that VIC in the presence of a control laser and a magnetic field can lead to large enhancement…

Quantum Physics · Physics 2016-07-28 Pardeep Kumar , Bimalendu Deb , Shubhrangshu Dasgupta

We present a novel system to calibrate millimeter-wave polarimeters for CMB polarization measurements. This technique is an extension of the conventional metal mirror rotation approach, however it employs cryogenically-cooled blackbody…

Instrumentation and Methods for Astrophysics · Physics 2012-05-01 M. Hasegawa , O. Tajima , Y. Chinone , M. Hazumi , K. Ishidoshiro , M. Nagai

We describe the design and performance of a microwave polarimeter used to make precision measurements of polarized astrophysical radiation in three microwave frequency bands spanning 26-36 GHz. The instrument uses cooled HEMT amplifiers in…

In the presence of strong magnetic fields, the vacuum becomes a birefringent medium. We show that this QED effect couples the direction of the polarization of photons leaving the NS surface, to the direction of the magnetic field along the…

Astrophysics · Physics 2009-09-29 Jeremy S. Heyl , Don Lloyd , Nir J. Shaviv

The design and performance of a wide bandwidth linear polarization modulator based on the Faraday effect is described. Faraday Rotation Modulators (FRMs) are solid-state polarization switches that are capable of modulation up to ~10 kHz.…

POLAR is space-borne detector designed for a precise measurement of gamma-ray polarization of the prompt emissions of Gamma-Ray Bursts in the energy range 50 keV - 500 keV. POLAR is a compact Compton polarimeter consisting of 40$\times$ 40…

We report on recent technical developments in the front- and back-ends for the four 20 m radio telescopes of the Japanese Very-Long-Baseline Interferometry (VLBI) project, VLBI Exploration of Radio Astrometry (VERA). We present a brief…

Instrumentation and Methods for Astrophysics · Physics 2022-12-21 Yoshiaki Hagiwara , Kazuhiro Hada , Mieko Takamura , Tomoaki Oyama , Aya Yamauchi , Syunsaku Suzuki

The spin polarization of hadrons is a key observable for probing the details of particle and nuclear interactions, offering information not available from other measurements. Currently, general-purpose spectrometers lack the capability to…

High Energy Physics - Experiment · Physics 2025-12-03 Chuang-Xin Lin , Xiao-Rong Lv , Boxing Gou , Ai-Qiang Guo , Yu-Tie Liang