Showing papers on "Polarization rotator published in 1973"

Poincaré sphere representation of partially polarized fields

Abstract: The use of points on the surface of the poincare sphere to represent the polarization state of fully polarized electromagnetic fields is extended to partially polarized fields by representing their polarization by points inside the sphere. The coordinates of a point \bar{W} representing the polarization state are shown to be simply related to the Stokes parameters. The center of the sphere represents a completely unpolarized wave, and the degree of polarization is given by the distance of the point \bar{W} from the center of the sphere. A simple formula is derived for calculating the power received by an antenna illuminated by a partially polarized wave. A method is described for measuring the polarization state by a number of intensity measurements.

On optical polarization measurements in liquid crystals

Abstract: ``Compensated'' nematic mixtures of cholestryl derivatives are very well suited as anisotropic solvents for optical polarization studies in the ultraviolet since these compounds are transparent to about 240 nm and can be homogeneously oriented by dc electric fields. Such mixtures have been prepared in a temperature range between 20 and 100 °C by only slight changes in the composition. Polarization experiments have been performed both in the liquid state above room temperature and in the ordered frozen state below −30 °C. The degree of absorption polarization has been calculated as function of the elements exi of the molar extinction coefficient tensor and the average orientations (order parameters Sxi xi) of the solute molecular axes xi. For symmetric molecules all elements exi (λ) and order parameters can be determined. Results of our polarization studies of anthracene, chrysene and a charge transfer complex are presented. Moreover, it is shown that measurements of the circular dichroism, observed in the...

A ray-optical analysis of thin-film polarization converters

Abstract: A compact formula is given for the Goos-Haenchen shifts occurring for total internal reflection of light from anisotropic media. This is used in a coupled-wave analysis of polarization conversion in thin-film waveguides deposited on optically birefringent substrates. A numerical example illustrates the considerable influence of the Goos-Haenchen shifts on the conversion length.

Light-guiding switch, modulator and deflector employing antisotropic substrate

Abstract: There is disclosed a light beam switching, modulating and deflecting device which is comprised of a thin dielectric film or strip waveguide deposited on an anisotropic (i.e., uniaxial) crystalline substrate. The guide and substrate parameters are selected so that one polarization of an optical wave is supported as a guided mode in the guide and the other, orthogonal polarization is not supported. Applied electric field components or acoustic strain components interact with the substrate to cause a coupling of the guided wave from the supported polarization to the unsupported polarization. The wave, upon being coupled to the unsupported polarization, is automatically and immediately radiated out of a guided mode into a freely propagating substrate mode. The unique principle of operation of the device, involving a combination of polarization discrimination in the guide and polarization coupling through an electro-optic or acousto-optic modulation of the substrate, eliminates the need for phase-matching. Noncritical, spatially uniform electric field or acoustic strain components applied to the substrate can thus provide the desired effect. The structure and operation of the device are thus generally simpler than those of similar prior art alternatives.

Adjustable polarization antenna system

Abstract: An adjustable polarization system is provided by the combination of an adjustable power divider and an orthogonal coupler. One terminal of the power divider is coupled to one terminal of the orthogonal coupler through a 90* polarization rotator, the second terminal of the power divider being coupled to a second terminal of the orthogonal coupler. By an adjustment in the power divider, the percentage of power to the input terminals of the orthogonal coupler are altered and consequently the polarization is adjusted.

Polarization of dye laser light

Abstract: The degree of polarization of dye laser light (Rhodamine B) under excitation by a beam of linearly polarized light (second harmonic of a ruby or neodymium-doped laser) has been studied experimentally by measuring the Stokes parameters of dye laser light at a wavelength of 0.6328 pm. The sign of degree of polarization is negative in the case of the ruby second harmonic (0,3471 pm), whereas it is positive in the case of the neodymium second harmonic (0.53 pm). Even in the case of illumination with the ruby second harmonic, the magnitude of the degree of polarization increases with the intensity of unconverted ruby laser light. The experimental fact that the degree of polarization of dye laser light is nearly as high as unity has been explained fairly well on the basis of the theory proposed by the authors.

On birefringence phenomena, associated with total reflection

Abstract: 2014 We study by phase-shift methods the birefringence properties of total reflection of a light beam at the separation plane between two isotropic homogeneous media. This includes the Goos-Hänchen longitudinal effect in wich a source of unpolarized light is split into two images, each of them linearly polarized, as well as the transverse shift recently investigated experimentally by Imbert, where the effect is between left and right circular polarizations. We give a general simple method for determining the polarizations and positions of the images. Tome 34 N° 5-6 MAI-JUIN 1973

Experimental properties of injection lasers. III. Current dependence of polarization

Abstract: The power distribution function which describes the shape and current dependence of the lateral beam is applied to a phenomenological model of weakly polarized injection lasers It predicts that the polarization of coherent power should drop rapidly from an infinite value at threshold to near unity at high drive Careful measurement of polarization of a laser representative of the model, with especial attention to rejection of the spontaneous emission, supports this conclusion The form of the power distribution function used in the analysis implies that lasers with strong polarization at high drive have large threshold differences of the two polarizations, suggesting that present theories of the source of polarization are inadequate The difficulty of interpreting the present results in terms of spatial hole burning or inhomogeneities is pointed out

Bulk nuclear polarization of solid3He

Abstract: Measurements are given on the bulk nuclear spin polarization in a liquid-solid3He mixture cooled by compressional cooling to below 5 mK in a magnetic field of 54.5 kG. Owing to the low Pauli spin susceptibility of liquid3He, the observed polarization is primarily due to solid3He. A maximum average nuclear polarization of 47% was observed, although the corresponding solid3He polarization is believed to be higher. Our novel detection system, using a dual directional coupler for cw NMR, is a simple and versatile means of working in the awkward frequency range around 180 MHz. We also report transient heating measurements in the3He system which indicate that the internal thermal equilibrium time in bulk solid3He on the3He melting curve appears to be quite short (less than 5 min) at these temperatures. One type of transient measurement is complicated by the dramatic effect of the contribution of the3He nuclear magnetization to the total local magnetic field. This contribution is considered via a simple model.

Polarization-dependent intensity transmittance of optical systems

Abstract: The intensity transmittance α of a linear nondepolarizing optical system is investigated as a function of the state of polarization of the incident light. For totally polarized incident light the state of polarization is completely described by a single complex variable χ. In the χ-plane, the loci of incident polarizations that experience equal attenuation or amplification [α(χ)=constant] upon passing through the system constitute a family of nonintersecting coaxal circles. The zero-radius point circles of the coaxal family represent two orthogonal polarizationsχ max andχ min that pass through the system with maximum and minimum transmittances, respectively. Simple elegant expressions are derived for α in terms of the propertiesχ max,χ min;α max andα min of the system. When χ is expressed in terms of the azimuth and the ellipticity of the polarization ellipse a generalized version of Malus' law is obtained which is applicable to any optical system. Special cases of optical systems are discussed. The condition that a Jones matrix represents an active system is derived. Such a system may amplify polarization states inside a circular domain in the complex χ-plane and attenuate all other states. The results for totally polarized incident light are used to derive the polarization-dependent intensity transmittance of the system for unpolarized and partially polarized incident light. A new set of three parameters is introduced to describe the state of polarization of partially polarized light. The polarization-dependent intensity transmittance is completely determined by four real quantities which can be measured photo-ellipsometrically.

Average form of polarization of partially polarized gaussian light

Abstract: The ratio between the components of the complex amplitudes of a plane, completely polarized, electromagnetic wave describes the state of polarization For partially polarized gaussian light, the average value of this ratio is found to be simply related to the elements of the coherency matrix This average is related to the degree of polarization and the cross-correlation function Its propagation through linear optical systems is discussed

Polarization Measurement of Coherent Bremsstrahlung from a Single Crystal of Silicon. I

Abstract: The linear polarization of coherent bremsstrahlung was measured by comparing one dimensionally projected angular distribution of symmetricpair electrons with the theory. The distribution was measured with a wire chamber on both the electron and positron sides independently of each other. polarizations obtained on both sides agreed well. The polarization was measured at 153 MeV for various orientations of the crystal. The polarization spectrum was in good agreement with the theory. A large polarization at the null injection angle of the incident electron beam to the crystal axis [110] is discussed in relation to a partial failure of the Born approximation and to the crystal dislocation. The systematic error for the polarization, temperature rise of the crystal, problems in the measuring method, etc. are discussed.

Polarizing effect of beam-splitter in two-beam interferometry

Abstract: Reflection and transmission at and through a metallic film change the polarization parameters of a beam of light. This implies that the two interfering beams of two-beam interferometers using such film as beam-splitter are different so far as the state of polarization is concerned. It is shown that in the resultant interference pattern there is a periodic variation of the state of polarization along with the periodic variation of intensity. Actual numerical calculations have been made to study the nature and extent of variation of polarization parameters due to the polarizing effect of an aluminium film coated on a glass-plate.

Second Order Non-Linear Coefficient of the Crystal Class: 3 m with D.C. Polarization

Abstract: Second order non-linear tensor of crystal class: 3 m can be obtained by knowing the different types of d.c. polarization as circular, linear and the polarization due to the electric field vector which lies in y-z plane and then in x-z plane of the crystal.

Connection system for waves with variable polarization

Abstract: An arrangement for combining the signal outputs from two antennas with crossed planes of polarization furnishes a constant output level regardless of the direction of rotation of the polarization of the incident wave. It is applicable particularly to the reception of signals from satellites.

The Electrical Polarization of 1,4-Dicyanobenzene

Abstract: The anomalous total electric polarization of 1,4-dicyanobenzene has been shown not to be due to high atom polarization by dielectric constant measurement of the solid substance and by its spectral ...