Showing papers on "Optical polarization published in 1982"
TL;DR: An intensity discriminator for optical pulses can be made with a birefringent fiber using an intensity-dependent state of polarization out of the fiber for separating the intense subpicosecond pulses from the weaker uncompressed background.
Abstract: An intensity discriminator for optical pulses can be made with a birefringent fiber. Such a discriminator would be useful for separating the intense subpicosecond pulses formed by solitonlike compression from the weaker uncompressed background. The discriminator utilizes an intensity-dependent state of polarization out of the fiber.
299 citations
TL;DR: It is shown that for lidar systems constrained to narrow beam-widths for polarization or other observations, accurate alignment is of great importance to lidar operations.
Abstract: The lidar crossover function f(R) in the lidar equation accounts for the incomplete overlap of the laser-pulse volume and the receiver field of view at short ranges and so is pertinent to near-surface returns from aerosols and precipitation. Using a Gaussian-intensity transverse profile for the laser pulse we present a comparatively simple formulation for f(R) and provide some numerical results for realistic lidar geometries, including the effects of optical axes misalignment. It is shown that for lidar systems constrained to narrow beam-widths (~1 mrad) for polarization or other observations, accurate alignment is of great importance to lidar operations.
66 citations
TL;DR: In this article, the authors describe the thermotropic phase transitions in several structurally related amphiphiles containing pyridinium head groups, and the results are discussed in relation to the calculated molecular dimensions obtained from space-fii molecular models.
Abstract: The present study describes the thermotropic phase transitions in several structurally related amphiphiles containing pyridinium head groups. From the combined results of differential scanning calorimetry (DSC), optical polarization microscopy, and X-ray diffraction, the thermotropic liquid-crystalline phases present in 1-3 and 10 have been characterized. For amphiphiles 1 and 10 a smectic-A phase was observed. The thermotropic liquid-crystalline state of 2 could be identified as a smectic-C phase. The tilt angle of the director was calculated to be ca 58O. The X-ray diffraction pattern of the mesophase of 3 could be best rationalized in terms of a smectic-H phase. The cell constants of the monoclinic lattice are a = 8.63 A, b = 4.79 A, c = 51.8 A, and @ = 132.6*, with two molecules per unit cell. The results are discussed in relation to the calculated molecular dimensions obtained from space-fii molecular models. Probable arrangements of the organized amphiphiles in the particular smectic phase are proposed.
64 citations
TL;DR: In this article, a general theory for polarization evolution characteristics in anisotropic single-mode optical fibers to which plural perturbations of different kinds are applied simultaneously is presented, based on modified coupled-mode theory.
Abstract: A general theory is presented for polarization evolution characteristics in anisotropic single-mode optical fibers to which plural perturbations of different kinds are applied simultaneously. This treatment is based on modified coupled-mode theory. Polarization performance in the system can be described by a simple projection rule when the birefringence caused by individual perturbation is known. Several examples of applications are classified according to their mode coupling properties in fused silica fibers.
50 citations
TL;DR: In this paper, the relationship between optical and radio properties of radio galaxies has been investigated and it was shown that most radio galaxies with optical nuclear emission are in fact polarized, indicating the existence of a simple geometrical relationship between the inner, optically emitting region and the outermost, radio-emitting region.
Abstract: Optical polarization position angles tend to align with large-scale radio structure in low polarization quasars1, indicating the existence of a simple geometrical relationship between the inner, optically-emitting region and the outermost, radio-emitting region. However, the meaning of the alignment is unclear because the cause of the optical polarization is unknown. If the polarization is caused by a synchrotron emission process then we are learning the direction of the magnetic field in the optically-emitting region. If it arises from scattering, then the position angle refers to the distribution of scatterers. At Lick Observatory we have been observing some quasars in the Stockman et al. sample1 spectropolarimetrically to distinguish between the two possibilities (J. S. Miller and R. R. J. A. in preparation). If the polarization arises from the continuum emission process, only the continuum is polarized. If due to scattering, some of the line emission is probably polarized too. I have obtained optical spectropolarimetry data and VLA radio maps for a sample of radio galaxies to identify and interpret such alignment effects. The entire data set will be published as part of a study of the relationship between optical and radio properties of radio galaxies (work in preparation). The results show that most radio galaxies with optical nuclear emission are in fact polarized. There is a population showing quasar alignment effect, and unexpectedly there is also a population showing a perpendicular relationship. Emission-line polarizations exhibit various behaviours but in all cases make it very likely that the polarizations of both groups arise from scattering or dust transmission rather than the emission process itself.
48 citations
TL;DR: The effect of birefringence on the resonance frequency of a closed-loop fiber-optic resonator is calculated.
Abstract: The effect of birefringence on the resonance frequency of a closed-loop fiber-optic resonator is calculated.
47 citations
46 citations
15 Jun 1982
TL;DR: In this paper, a millimeter-wave antenna-mixer structure on a dielectric substrate is described, and measurements of a 10 GHz model in a quasi-optical system show good conversion loss and LO-to-RF isolation exceeding 30 dB.
Abstract: A millimeter-wave antenna-mixer structure on a dielectric substrate is described. Measurements of a 10-GHz model in a quasi-optical system show good conversion loss and LO-to-RF isolation exceeding 30 dB. A GaAs monolithic integrated circuit seems feasible.
44 citations
TL;DR: The theory for phase conjugation in stimulated scattering is described in detail in detail as mentioned in this paper, and the basic experimental results on the conjugations are also discussed in detail, as well as the intervals of values of various parameters in which the conjogate configuration (the specklon) exists.
Abstract: Various aspects of optical phase conjugation are discussed: the properties of the conjugate wave, its potential applications, the basic conjugation methods, and a brief history of the question. The theory for phase conjugation in stimulated scattering is set forth in detail. The basic experimental results on this conjugation method are also discussed in detail. Phase conjugation occurs because that configuration of the back-scattered field which has the conjugate wavefront is amplified to the greatest extent (at a doubled gain) in the intense speckle-inhomogeneous conjugate wave in a medium in which stimulated scattering occurs. Because of the large overall amplification in stimulated scattering, all the other, uncorrelated, configurations of the spontaneously scattered nucleating waves are amplified by a factor of 107 less and are discriminated against. The intervals of values of the various parameters in which the conjugate configuration (the specklon) exists are discussed theoretically, as is the effect of nonlinear selection and saturation on phase conjugation in stimulated scattering. There is a review of experimental results on the first observation of the effect, on the measurement of the angular structure of the uncorrelated waves and of the extent to which they are discriminated against, on the phase fluctuations of the conjugate wave, on the conjugation of subthreshold and depolarized radiation, and on phase conjugation in stimulated scattering in focused beams and for other scattered-wave amplification mechanisms.
44 citations
TL;DR: By careful electrode design, a 1.7-GHz modulation bandwidth for a Ti:LiNbO(3) integrated-optic TE ?
Abstract: By careful electrode design we have achieved a 1.7-GHz modulation bandwidth for a Ti:LiNbO(3) integrated-optic TE ? TM mode-converter modulator. Because of the wavelength selectivity of this modulator, it is an attractive device for simultaneously providing multiplexing and signal encoding in future wavelength-multiplexed single-mode light-wave systems.
36 citations
TL;DR: In this paper, the first direct observation of anisotropic state filling in semiconductors was made by the first author, who observed that self-diffraction is observed from transient orientational gratings produced in germanium by a filling of the optically coupled states by direct absorption of the nearly monochromatic polarized exciting radiation.
Abstract: Picosecond self-diffraction is observed from transient orientational gratings produced in germanium by an anisotropic (in $k$ space) filling of the optically coupled states by direct absorption of the nearly monochromatic polarized exciting radiation, the first direct observation of anisotropic state filling in semiconductors. A new theoretical model is presented briefly; agreement is found with all aspects of the experiment.
TL;DR: In this paper, the spectral properties of three dust-enshrouded carbon stars were analyzed using optical spectropolarimetry, and it was shown that the extremely peculiar spectral behavior of polarization for GL 1403 implies two orthogonally polarized spectral components: one due to hot dust; the other, the stellar photosphere.
Abstract: Optical spectropolarimetry of three dust-enshrouded carbon stars reveals very large degrees of polarization, requiring highly organized circumstellar dust shells around each object. The extremely peculiar spectral behavior of polarization for GL 1403 implies two orthogonally polarized spectral components: one due to hot dust; the other, the stellar photosphere. The observations of this object are interpreted in terms of a cool dust torus and bipolar scattering lobes. Such a structure, together with a 635 day photometric period derived from IR observations, supports evolution of high-mass carbon variables into bipolar nebulae.
TL;DR: In this paper, a spatial technique based on a visibility maximum position measurement in an interferometer was used to measure the wavelength dependence of the modal dispersion by varying optical source wavelength between 821 and 904 nm.
Abstract: Polarization mode dispersion in elliptical core single-mode fibers has been measured by a spatial technique based on a visibility maximum position measurement in an interferometer. Using the technique, wavelength dependence of the modal dispersion has been measured by varying optical source wavelength between 821 and 904 nm. As a result, contribution of geometrical and strain birefringences on the modal dispersion has been evaluated, and normalized frequency dependence of the modal dispersion has been clarified. Moreover, the dispersion compensation effect has been observed by interchanging the fast and slow modes of two fibers at a splice point. The experimental results reveal that the spatial technique is very useful for polarization mode dispersion measurement.
TL;DR: It is shown that the development of crimp structure is accompanied by morphological changes in fibroblasts and is commonly observed in adult tendons, ligaments, and other collagenous tissues which support tension.
TL;DR: In this paper, a new kind of microwave-optical double-resonance experiment monitoring the nonlinear interaction between microwave radiation and a laser beam via changes in light polarization was demonstrated.
Abstract: We have demonstrated a new kind of microwave-optical double-resonance experiment monitoring the nonlinear interaction between microwave radiation and a laser beam via changes in light polarization. Compared with conventional microwave-optical double-resonance experiments signals are observed at considerably lower laser power density and with greatly improved resolution.
TL;DR: In this article, near-infrared polarimetry was performed for 15 compact sources within 100'' (5 pc) of the galactic center, and the results support the association of all 15 with the center.
Abstract: Near-infrared polarimetry is reported for 15 compact sources within 100'' (5 pc) of the galactic center; the results support the association of all 15 with the center. No intrinsic polarization stronger than 2% at 2 ..mu..m is detected from source 16. The polarization at 11.5 ..mu..m is probably due to emission by aligned grains in optically thin dust clouds surrounding luminous stars; these grains are aligned by streaming driven by radiation pressure. The stars that power at least three of the 11.5 ..mu..m sources can be observed directly in the near-infrared.
TL;DR: In this article, a polarizer between an antireflection-coated GaAlAs laser diode and an external optical feedback system is used to control the polarization characteristics of the output light and to select the single or multilongitudinal modes (TE/TM) by adjusting the orientation of the polarizer.
Abstract: A polarizer between an antireflection‐coated GaAlAs laser diode and an external optical feedback system is used to control the polarization characteristics of the output light and to select the single or multilongitudinal modes (TE/TM) by adjusting the orientation of the polarizer.
TL;DR: In this article, the thermal stress distributions in both the core and cladding of a single-mode elliptical optical fiber are analyzed and a simple formula is given for the calculation of bire-fringence caused by the thermal stresses.
Abstract: The thermal stress distributions in both the core and cladding of a single-mode elliptical optical fibre are analysed. It is found that the stresses in the core do not vary with position but the stresses in the cladding are complicated functions of position. A simple formula is given for the calculation of bire-fringence caused by the thermal stresses.
TL;DR: Analysis shows that the isolation inherent in acoustooptic modulators is impaired if the acoustic wave is partially retroreflected, and this effect generates additional spectral components in both the deflected and the re-troreflected light beam.
Abstract: Analysis shows that the isolation inherent in acoustooptic modulators is impaired if the acoustic wave is partially retroreflected. This effect generates additional spectral components in both the deflected and the retroreflected light beam. The theoretical findings were confirmed by experiments at 10.6 μm, where an optical isolation of 40 dB was measured for a device with 23% deflection efficiency.
TL;DR: A 3-D viewing system based on bicircular polarization for channelizing the stereo pair of images to discern the 3- D color image from conventional 2-D color picture tube screens is proposed and the supremacy of bicIRCular polarization over orthogonal polarization is proved analytically.
Abstract: A 3-D viewing system based on bicircular polarization for channelizing the stereo pair of images to discern the 3-D color image from conventional 2-D color picture tube screens is proposed. Suitable 3-D color TV system compatible to the conventional 2-D color TV standards and equipments is described for generating bicircularly polarized optical images. This viewing system unlike the orthogonally plane polarized ones does not restrict the head movements of the viewer while seeing the picture tube for 3-D perception. The supremacy of bicircular polarization over orthogonal polarization is proved analytically.
TL;DR: In this paper, the authors measured the optical polarizations of two highly polarized Seyfert 1 galaxies IC 4329A and Mrk 376 using a two-channel photoelectric Pockels cell polarimeter, a single-channel scanner, and a digicon attached to a flint prism spectrograph.
Abstract: Measurements of the optical polarizations of the two highly polarized Seyfert 1 galaxies IC 4329A and Mrk 376 are presented. Continuum and line polarization of the two objects were observed with the Steward Observatory 2.25-m telescope using a two-channel photoelectric Pockels cell polarimeter, a single-channel scanner, and a digicon attached to a flint prism spectrograph. Results indicate that, for both galaxies, the emission line polarization and underlying continuum polarization are identical, rising toward short wavelengths, and therefore must be explained by a common mechanism. Such a mechanism is suggested to involve polarization produced by aligned grains in the galactic disk. A model for polarization in IC 4329A by this mechanism predicts a grain size three times smaller than Galactic polarizing grains, as well as a visual extinction of about 2 magnitudes, a gas to dust mass ratio close to 100 and a polarization to extinction ratio comparable to the Galactic ratio.
TL;DR: In this article, the degree of orientation from optical polarization correlates with the orientation suggested by resistivity measurements, and it is shown that carbon black aggregates in these compression molded composites are oriented.
Abstract: Resistivity measurement on carbon black‐polyvinylchloride (PVC) composites combined with Monte Carlo calculations on the percolation threshold of a two‐dimensional system of oriented sticks has suggested that the carbon black aggregates in these compression molded composites are oriented. Although electron microscopy failed to disclose structure in the composite, polarized infrared transmittance measurements do provide direct evidence for the orientation of carbon black aggregates. The degree of orientation from optical polarization correlates with orientation suggested by the resistivity measurements.
TL;DR: In this paper, the optical polarization vectors which measurements have shown to be parallel to the pronounced dark lanes of such galaxies as NGC 5128 and 4590 are interpreted as the consequence of a large scale, systematic field parallel to a dark lane that leads to the alignment of the grains.
Abstract: The optical polarization vectors which measurements have shown to be parallel to the pronounced dark lanes of such galaxies as NGC 5128 and 4590 are interpreted as the consequence of a large scale, systematic field parallel to the dark lane that leads to the alignment of the grains. It is suggested that such polarization may also be produced by scattering off grains concentrated in the dark lane. It is recommended that there be further observational tests of the hypothesis that the observed polarization indicates the magnetic field in the galaxy.
TL;DR: In this article, the multiple section Delta Beta reversal polarization-independent integrated optic switches have been designed and demonstrated at a 0.83 µm wavelength using a Gaussian taper function to achieve low crosstalk.
Abstract: Multiple section Delta Beta reversal polarization-independent integrated optic switches have been designed and demonstrated at a 0.83 µm wavelength. These switches use a Gaussian taper function to achieve low crosstalk in the parallel state. Calculated switch characteristics as related to an ideal Gaussian taper and approximations that can be fabricated by mask making are described. Experimental demonstration shows that these switches have useful switching characteristics with relatively high switching voltages.
Patent•
06 Jul 1982TL;DR: A polarimetric image recorder which records only the net polarization of the viewed scene is described in this paper. But the reader is not equipped with an optical lens, and it cannot project the light originating from a viewed scene onto a thin layer of an alkali halide crystal containing anisotropic color centers.
Abstract: A polarimetric image recorder which records only the net polarization of the viewed scene. An optical lens system projects the light originating from the viewed scene onto a thin layer of an alkali halide crystal containing anisotropic color centers. Polarized light reorients the color centers and creates a net polarization in the layer. The net polarization of the layer is read by such means as shining polarized light through the layer and then through a polarizer set perpendicularly to the polarization of the light source. Whatever light is viewed through the reader represents a net polarization in the scene.
TL;DR: In this article, the evolution of the polarisation of a field propagating in a birefringent single-mode optical fiber was examined and the explicit dependence of the degree of polarisation on pulse duration, coherence time of the source and chromatic delay of the fibre was derived.
Abstract: We examine the evolution of the polarisation of a field propagating in a birefringent single-mode optical fibre. The explicit dependence of the degree of polarisation on pulse duration, coherence time of the source and chromatic delay of the fibre is derived.
03 May 1982
TL;DR: In this article, angle resolved scattering of synchrotron radiation incident on optical surfaces has been measured in the energy range from 75-750 eV, typically from 3 degrees to at least 40 degrees from the specular direction.
Abstract: Angle resolved scattering of synchrotron radiation incident on optical surfaces has been measured in the energy range from 75-750 eV. The scattering was measured in the plane of incidence, typically from 3 degrees to at least 40 degrees from the specular direction, with an angle of incidence of 84 degrees from the surface normal. The incident radiation was polarized either parallel or perpendicular to the plane of incidence, but the polarization state of the scattered radiation was not measured. Polished and diamond-turned optical surfaces were studied. The diamond-turned surfaces were turned with an interrupted cut, and measurements were taken with the direction of the grooves both parallel and perpendicular to the plane of incidence. The three diamond-turned surfaces were Cu, electroless Ni on Cu, and electroplated Au on electroless Ni on Cu. The polished samples included evaporated Au on a sapphire substrate.