Demonstration of an optical polarization magnifier with low birefringence

In any polarimetric measurement technique, enhancing the laser polarization change of a laser beam before it reaches the analyzer can help in improving the sensitivity. This can be performed using an optical component having a large linear dichroism, the enhancement factor being equal to the square root of the ratio of the two transmission factors. A pile of parallel plates at Brewster incidence looks appropriate for realizing such a polarization magnifier. In this paper, we address the problem raised by the interference in the plates and between the plates, which affects the measurement by giving rise to birefringence. We demonstrate that wedged plates provide a convenient and efficient way to avoid this interference. We have implemented and characterized devices with 4 and 6 wedged plates at Brewster incidence which have led to a decisive improvement of the signal to noise ratio in our ongoing Parity Violation measurement.Comment: 08 october 200

The language of Einstein spoken by optical instruments

Einstein had to learn the mathematics of Lorentz transformations in order to complete his covariant formulation of Maxwell's equations. The mathematics of Lorentz transformations, called the Lorentz group, continues playing its important role in optical sciences. It is the basic mathematical language for coherent and squeezed states. It is noted that the six-parameter Lorentz group can be represented by two-by-two matrices. Since the beam transfer matrices in ray optics is largely based on two-by-two matrices or $ABCD$ matrices, the Lorentz group is bound to be the basic language for ray optics, including polarization optics, interferometers, lens optics, multilayer optics, and the Poincar\'e sphere. Because the group of Lorentz transformations and ray optics are based on the same two-by-two matrix formalism, ray optics can perform mathematical operations which correspond to transformations in special relativity. It is shown, in particular, that one-lens optics provides a mathematical basis for unifying the internal space-time symmetries of massive and massless particles in the Lorentz-covariant world.Comment: LaTex 8 pages, presented at the 10th International Conference on Quantum Optics (Minsk, Belarus, May-June 2004), to be published in the proceeding

Fresnel coefficients as hyperbolic rotations

We describe the action of a plane interface between two semi-infinite media in terms of a transfer matrix. We find a remarkably simple factorization of this matrix, which enables us to express the Fresnel coefficients as a hyperbolic rotation.Comment: 6 pages, 3 figure

Experimental determination of the degree of quantum polarisation of continuous variable states

We demonstrate excitation-manifold resolved polarisation characterisation of continuous-variable (CV) quantum states. In contrast to traditional characterisation of polarisation that is based on the Stokes parameters, we experimentally determine the Stokes vector of each excitation manifold separately. Only for states with a given photon number does the methods coincide. For states with an indeterminate photon number, for example Gaussian states, the employed method gives a richer and more accurate description. We apply the method both in theory and in experiment to some common states to demonstrate its advantages.Comment: 5 page

Spectroscopic distinction between the normal state pseudogap and the superconducting gap of cuprate high T_{c} superconductors

We report on broad-band infrared ellipsometry measurements of the c-axis conductivity of underdoped RBa_{2}Cu_{3}O_{7-d} (R=Y, Nd, and La) single crystals. Our data provide a detailed account of the spectral weight (SW) redistributions due to the normal state pseudogap (PG) and the superconducting (SC) gap. They show that these phenomena involve different energy scales, exhibit distinct doping dependencies and thus are likely of different origin. In particular, the SW redistribution in the PG state closely resembles the one of a conventional charge- or spin density wave (CDW or SDW) system.Comment: 4 pages, 4 figure

Iwasawa Effects in Multi-layer Optics

There are many two-by-two matrices in layer optics. It is shown that they can be formulated in terms of a three-parameter group whose algebraic property is the same as the group of Lorentz transformations in a space with two space-like and one time-like dimensions, or the $Sp(2)$ group which is a standard theoretical tool in optics. Among the interesting mathematical properties of this group, the Iwasawa decomposition drastically simplifies the matrix algebra under certain conditions, and leads to a concise expression for the S-matrix for transmitted and reflected rays. It is shown that the Iwasawa effect can be observed in multi-layer optics, and a sample calculation of the S-matrix is given.Comment: RevTex 10 pages including 1 psfi

Osteoma Cutis Associated with Nevus Sebaceus: Case Report and Review of Cutaneous Osteoma-associated Skin Tumors (COASTs)

Osteoma cutis is a benign cutaneous lesion characterized by the presence of bone within the dermis or subcutaneous fat. It most often develops in association with other skin lesions such as cutaneous tumors. Nevus sebaceus is a benign hamartoma of the skin that is composed of epidermal and dermal components. It most commonly appears on the scalp and may give rise to either benign or malignant secondary neoplasms. The clinical and pathologic features of a 36-year-old man with a nevus sebaceus and associated osteoma cutis are described. In addition, osteoma cutis-associated neoplasms are reviewed. Secondary osteoma cutis has been observed with both benign and malignant neoplasms as well as various non-neoplastic skin conditions. However, to the best of our knowledge, osteoma cutis has not previously been described in association with nevus sebaceus. Nevus sebaceus can now be added to the list of cutaneous osteoma-associated skin tumors (COASTs)

MARVEL analysis of high-resolution rovibrational spectra of ¹³C¹⁶O₂

A set of empirical rovibrational energy levels, obtained through the MARVEL (measured active rotational-vibrational energy levels) procedure, is presented for the 13C16O2 isotopologue of carbon dioxide. This procedure begins with the collection and analysis of experimental rovibrational transitions from the literature, allowing for a comprehensive review of the literature on the high-resolution spectroscopy of 13C16O2, which is also presented. A total of 60 sources out of more than 750 checked provided 14,101 uniquely measured and assigned rovibrational transitions in the wavenumber range of 579–13,735 cm-1. This is followed by a weighted leastsquares refinement yielding the energy levels of the states involved in the measured transitions. Altogether 6318 empirical rovibrational energies have been determined for 13C16O2. Finally, estimates have been given for the uncertainties of the empirical energies, based on the experimental uncertainties of the transitions. The detailed analysis of the lines and the spectroscopic network built from them, as well as the uncertainty estimates, all serve to pinpoint possible errors in the experimental data, such as typos, misassignment of quantum numbers, and misidentifications. Errors found in the literature data were corrected before including them in the final MARVEL dataset and analysi

Polarization resolved angular patterns in nematic liquid crystal cells

We study the angular structure of polarization of light transmitted through a nematic liquid crystal (NLC) cell by theoretically analyzing the polarization state as a function of the incidence angles. For a uniformly aligned NLC cell, the $4\times 4$ matrix formalism and the orthogonality relations are used to derive the analytical expressions for the transmission and reflection matrices. The polarization resolved angular patterns in the two-dimensional projection plane are characterized in terms of the polarization singularities: C points (points of circular polarization) and L lines (lines of linear polarization). In the case of linearly polarized plane waves incident on the homeotropically aligned cell, we present the results of detailed theoretical analysis describing the structure of the polarization singularities. We apply the theory to compute the polarization patterns for various orientational structures in the NLC cell and discuss the effects induced by the director orientation and biaxiality.Comment: pdflatex, rextex4, 22 pages, 7 figures (jpeg

Low-temperature far-infrared ellipsometry of convergent beam

Development of an ellipsometry to the case of a coherent far infrared irradiation, low temperatures and small samples is described, including a decision of the direct and inverse problems of the convergent beam ellipsometry for an arbitrary wavelength, measurement technique and a compensating orientation of cryostat windows. Experimental results are presented: for a gold film and UBe13 single crystal at room temperature (lambda=119 um), temperature dependencies of the complex dielectric function of SrTiO3 (lambda=119, 84 and 28 um) and of YBa2Cu3O7-delta ceramic (lambda=119 um).Comment: 14 pages, 6 figure