Related papers: Variable-delay Polarization Modulators for Cryogen…
We investigate the polarization modulation properties of a variable-delay polarization modulator (VPM). The VPM modulates polarization via a variable separation between a polarizing grid and a parallel mirror. We find that in the limit…
Variable-delay Polarization Modulators (VPMs) are currently being implemented in experiments designed to measure the polarization of the cosmic microwave background on large angular scales because of their capability for providing rapid,…
The search for inflationary primordial gravitational waves and the measurement of the optical depth to reionization, both through their imprint on the large angular scale correlations in the polarization of the cosmic microwave background…
We present first results of Hertz/VPM, the first submillimeter polarimeter employing the dual Variable-delay Polarization Modulator (dual-VPM). This device differs from previously used polarization modulators in that it operates in…
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…
A primordial degree of circular polarization of the Cosmic Microwave Background is not observationally excluded. The hypothesis of primordial dichroism can be quantitatively falsified if the plasma is magnetized prior to photon decoupling…
Polarization modulation is a powerful technique to increase the stability of measurements by enabling the distinction of a polarized signal from dominant slow system drifts and unpolarized foregrounds. Furthermore, when placed as close to…
Spider is a balloon-borne array of six telescopes that will observe the Cosmic Microwave Background. The 2400 antenna-coupled bolometers in the instrument will make a polarization map of the CMB with ~degree resolution at 150 GHz and 95…
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…
The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne telescope designed to measure the polarization of the Cosmic Microwave Background on large angular scales. PIPER will map 85% of the sky at 200, 270, 350, and 600 GHz…
We have developed a correlation radiometer at 33 GHz devoted to the search for residual polarization of the Cosmic Microwave Background (CMB). The two instruments`s outputs are linear combination of two Stokes Parameters (Q and U or U and…
Measurements of the polarization of the cosmic microwave background (CMB) radiation are expected to significantly increase our understanding of the early universe. We present a design for a CMB polarimeter in which a cryogenically cooled…
We introduce a laser heterodyne polarimeter designed for the precision measurement of sub $\mu\mathrm{rad}$ differential phase shifts due to birefringence. The polarimeter will be used in an initial testbed for a potential future vacuum…
Mm and sub-mm waves polarimetry is the new frontier of research in Cosmic Microwave Background and Interstellar Dust studies. Polarimeters working in the IR to MM range need to be operated at cryogenic temperatures, to limit the systematic…
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…
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,…
The V-mode polarization of the Cosmic Microwave Background is discussed in a weakly magnetized plasma. The VV and VT angular power spectra are computed for adiabatic initial conditions of the Einstein-Boltzmann hierarchy. Depending upon the…
We present a one-port calibration technique for characterization of beam waveguide components with a vector network analyzer. This technique involves using a set of known delays to separate the responses of the instrument and the device…
This paper presents a polarization calibration method applied to a microwave polarimeter demonstrator based on a near-infrared (NIR) frequency up-conversion stage that allows both optical correlation and signal detection at a wavelength of…
Several on-going and future experiments use a Stokes polarimeter (i.e. a rotating wave plate followed by a steady polarizer and by an unpolarized detector) to measure the small polarized component of the Cosmic Microwave Background. The…