Showing papers on "Circular polarization published in 1971"
TL;DR: Beetle reflecting layers which incorporate uric acid have twenty times greater optical rotatory power compared with reflecting layers lacking this component, and Mathematical treatments dealing with helicoidal reflectors predict the form opticalRotatory power to be a function of the square of the birefringence, which is in agreement with the experimental observations.
Abstract: The iridescent cuticle of certain Rutelino scarab beetles, which is a form optically active and selectively reflects circularly polarized light, incorporates an NH 4 OH -extractable component The ultraviolet absorption spectrum of this component, together with its chromatographic and refractive properties, identify it as uric acid (2,6,8-trihydroxypurine). All species of Plusiotis examined have uric acid in their reflecting layers, as do several species of Anoplognathus. Plusiotis resplendens has a reflecting layer with a uric acid volume fraction of 0.7, P . optima a volume fraction of 0.6. The reflecting layer of P . resplenden s has an anticlockwise helicoidal architecture, the optical thickness of the helicoidal p itch being such that it constructively interferes with visible light wavelengths. An anticlockwise helicoid constructively interferes with only the left circularly polarized component of incident light, right circularly polarized light being transmitted without attenuation. P. resplendens has a 1.8 /xm thick unidirectional layer embedded within the helicoid which functions as a perfect halfwave retardation plate for wavelength 590 nm . This halfwave plate enables the helicoidal reflector in this species to reflect both left and right circularly polarized components of incident light. After passing through the halfwave plate, transmitted right circularly polarized light becomes left circularly polarized ; this light is now reflected and emerges from the cuticle right circularly polarized, after passing back through the halfwave plate. Consequently the total reflectivity of circularly polarized incident light is greater in P. resplendens than in any other species examined; the plate also reduces multiple internal reflexions. Interferometric analysis of the refractive properties of the helicoidal reflectors in species of Plusiotis showed that the ordered incorporation of uric acid increases the birefringence of the system by a factor of five times, e.g. the in tact birefringence of the unidirectional layer of P . resplendens is 0.166 at wavelength 560 nm ; after uric acid extraction the birefringence is reduced to 0.034. As the coefficient of reflexion of a helicoidal reflector is directly proportional to the birefringence of the individual planes comprising the helicoid, beetles incorporating uric acid into their reflecting surfaces reflect circularly polarized light far more efficiently than beetles lacking uric acid. Refractive index values for a single multicomponent plane of the helicoid have been summarized as a biaxial indicatrix, with the Z axis tilte dat 45° to the plane of the epicuticle. Beetle reflecting layers which incorporate uric acid have twenty times greater optical rotatory power compared with reflecting layers lacking this component. Mathematical treatments dealing with helicoidal reflectors predict the form optical rotatory power to be a function of the square of the birefringence, which is in agreement with the experimental observations. To enable uric acid to have the optical effects mentioned above, an epitaxial incorporation into the helicoidal framework is necessary. Although uric acid is a common cytoplasmic reflecting material in arthropods, this is the first record of its presence in an extracellular (cuticular) reflector.
169 citations
127 citations
TL;DR: In this paper, techniques for analysis and synthesis of linear optical systems involving polarization effects are related and extended through full exploitation of the algebra of complex 2 × 2 matrices, and they are shown to be useful for the analysis of optical optical systems.
Abstract: Techniques for analysis and synthesis of linear optical systems involving polarization effects are related and extended through fuller exploitation of the algebra of complex 2 × 2 matrices.
100 citations
TL;DR: Preliminary observations on Mars, Venus, Mercury and the Moon demonstrate the generality of the circular polarization of scattered light from Jupiter and its potential usefulness.
Abstract: Scattered light circular polarization data from Jupiter and other planets indicating nonmagnetic origin
74 citations
TL;DR: In this paper, the C2 symmetry of I and II is taken into account with the aid of expressions that are derived for nonrigid molecules having a twofold axis of symmetry.
Abstract: The n‐π* transitions (absorption, circular dichroism, luminescence, linear and circular polarization of luminescence) of trans‐β‐hydrindanone (I) and trans‐β‐thiohydrindanone (II) are discussed. The C2 symmetry of I and II is taken into account with the aid of expressions that are derived for nonrigid molecules having a twofold axis of symmetry. This allows the absorption of I to be split into a part due to transitions polarized along the twofold axis (z axis) and a part due to x, y‐polarized vibration‐induced transitions. Accurate values for the electric and magnetic transition moments then are obtained. The vibrational structure of absorption and fluorescence and the latter's low degree of circular polarization are related to nonplanarity of the carbonyl group in the 1(n → π*) state. A larger nonplanarity probably is present in the triplet state of I. Circular polarization in the fluorescence was also observed when racemic I was excited with circularly polarized light. For the absorption of II, an upper...
49 citations
TL;DR: In this article, the propagation of polarized light within the cholesteric structure along its helical axis is conveniently expressed in terms of four 2-by-2 matrix operators, which are useful in studying the change in the state of polarization of a beam propagating along the helicalaxis.
Abstract: The propagation of polarized light within the cholesteric structure along its helical axis is conveniently expressed in terms of four 2-by-2 matrix operators. This description is useful in studying the change in the state of polarization of a beam propagating along the helical axis. The well-known properties of the liquid crystals come out as natural consequences of the properties of these operators. In particular, for a certain region of wavelengths as the beam propagates along the helical axis, a vector representing the state of polarization in Stokes space precesses about the s3 axis. The s3 axis stands for circular polarization. Furthermore, owing to the properties of the matrix operators, if the propagation of polarized light within the liquid crystal is described in diagonal form for propagation in one direction along the helical axis, then it cannot have a diagonal form for propagation in the opposite direction.
40 citations
Patent•
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TL;DR: An optical filter system capable of transmitting light at substantially all wavelengths of incident radiation while simultaneously rejecting radiation at a single wavelength band or plurality of wavelength bands within the incident radiation is described in this paper.
Abstract: An optical filter system capable of transmitting light at substantially all wavelengths of incident radiation while simultaneously rejecting radiation at a single wavelength band or plurality of wavelength bands within the incident radiation is described. The system employs optically negative liquid crystal films which are the same in intrinsic rotatory sense and means for converting circularly polarized light of one sense, e.g., right handed, to circularly polarized light of the opposite sense, e.g., left handed.
40 citations
TL;DR: In this paper, the effect of reabsorption and Faraday rotation on the degree of circular polarization in synchrotron radiation has been investigated, and it is shown that the effect is independent of the presence of an ambient medium.
Abstract: Formulas describing synchrotron radiation are extended to include the effect of the presence of an ambient medium and the effect of reabsorption and Faraday rotation on the degree of circular polarization. Results are: (1) The onset of Razin-Tsytovich suppression has no significant effect on the degree of circular polarization. (2) The onset of self-absorption in a source subject to weak Faraday rotation (negligible Faraday rotation in an absorption length) causes the degree of circular polarization to reverse its sign and to decrease (by between one half and one quarter for typical parameters) in magnitude. (3) As in (2) but for strong Faraday rotation (many rotations of the plane of polarization in an absorption length) the degree of circular polarization also reverses its sign and becomes slightly smaller in magnitude than for weak Faraday rotation.
39 citations
TL;DR: In this paper, G195-19 circular polarization measurements of continuum radiation in broad band, using electro-optically switched polarimeter were performed using an EO-SWIPT.
Abstract: White dwarf G195-19 circular polarization measurements of continuum radiation in broad band, using electro-optically switched polarimeter
37 citations
36 citations
TL;DR: In this paper, the authors derived a general solution for the mixing of two states by a magnetic field and showed that all of the anomalous experimental data are explained if (a) the presumably degenerate pair of excited states are split.
Abstract: Recent experimental studies have reported anomalous and contradictory results for the absorption of left and right circularly polarized light (LCPL and RCPL) by zinc and magnesium coproporphyrins in the presence of a magnetic field: for both compounds, the absorption bands for right and left circularly polarized light have distinctly different shapes at room temperature; at 77°K unexplained shoulders appear in the absorption spectra for both polarizations for the magnesium but not for the zinc compound; the value of the angular momentum of the lowest energy excited state computed from the separation of the peaks of the LCPL and RCPL absorption bands differs from the value obtained from magnetic circular dichroism (MCD) experiments by nearly 50%; no shape anomalies were observed in the MCD spectra. We derive a general solution for the mixing of two states by a magnetic field and show that all of the anomalous experimental data are explained if (a) the presumably degenerate pair of excited states are split ...
01 Jan 1971
TL;DR: In this article, two peculiarities of the magnetic splitting of a line in sunspot spectra have been investigated, and the nature of these effects is discussed, including the anomalous splitting of the π-component of the Zeeman triplets.
Abstract: Two peculiarities of the magnetic splitting of a line in sunspot spectra have been investigated. The one is that in a rather small region of the penumbra near the umbra-penumbra boundary the π-component is absent in one circular polarization spectrum while both σ-components are present. In the spectrum of opposite circular polarization the σ-components are absent but the π-component is present. The second peculiarity consists of the anomalous splitting of the π-component of Zeeman triplets which are of the same and opposite signs in comparison with splitting of the σ-components. The nature of these effects is discussed.
TL;DR: In this article, it was pointed out that the values measured for the circular polarization for Jupiter and Venus are of the magnitude expected for sunlight reflected by a cloudy planetary atmosphere, and variations of the sense of the polarization with phase angle and with location on the planetary disk are also consistent with expectations for reflection by clouds.
Abstract: Measurements of circular polarization of visible light from planets have recently been reported. It is pointed out that the values measured for the circular polarization for Jupiter and Venus are of the magnitude expected for sunlight reflected by a cloudy planetary atmosphere. The variations of the sense of the polarization with phase angle and with location on the planetary disk are also consistent with expectations for reflection by clouds.
TL;DR: In this article, the degree of polarization of the photoluminescence was used to determine the spin-polarized electrons in the conduction band of p-type GaSb by excitation with σ+ or σ− polarized light.
Abstract: Spin-polarized electrons are created in the conduction band of p-type GaSb by excitation with σ+ or σ− circularly polarized light. The degree of polarization of the photoluminescence is used to mea...
TL;DR: In this article, the Rosenfeld-Condon formula for the angle of optical rotation is derived without recourse to Maxwell's equations, and the relationship between refractive index and molecular polarizability is also derived using quantum electrodynamics.
Abstract: The phenomenon of optical activity is analyzed as a quantum two‐state process with transitions between photon states of perpendicular plane polarizations, but with the same momentum. The matrix element connecting the two states is computed using quantum electrodynamics. The Rosenfeld—Condon formula for the angle of optical rotation is derived without recourse to Maxwell's equations. The relationship between refractive index and molecular polarizability is also derived using quantum electrodynamics. The theory is extended to obtain the difference between refractive indices of an optically active medium with respect to right and left circularly polarized light and the difference is related to optical rotation.
TL;DR: THE AUTHORS have discovered circular polarization of the reflected light from Jupiter, the first detection at optical wavelengths of this type of polarization in light from a planet.
Abstract: WE have discovered circular polarization of the reflected light from Jupiter, the first detection at optical wavelengths of this type of polarization in light from a planet. The discovery was made at Mauna Kea Observatory, Hawaii, with a photoelastic polarimeter used also in measurements on magnetic white dwarf stars1. The first results were obtained with the 88 inch telescope on the night of March 31, 1971, and protracted observations were made with a 24 inch telescope on the nights of April 11, 20 and 21.
TL;DR: In this paper, the circular polarization of 482 keV and 396 keV transition in 175Lu has been calculated and pairing effects and short range correlations have been considered, and the conventional weak interaction model is too small compared to the measured values.
TL;DR: Periodic variations in circular polarization of continuum radiation of white dwarf G195-19 from 3800 to 5400 A from 2.5 to 3.5 GHz were reported in this article.
Abstract: Periodic variations in circular polarization of continuum radiation of white dwarf G195-19 from 3800 to 5400 A
Patent•
04 Mar 1971
TL;DR: In this article, a ring laser with multiple polarization and/or propagation direction modes is modulated by means of force-responsive devices such as amorphous quartz elements, which are used in gravimeters, pressure altimeters and pressure measurement devices.
Abstract: Electromagnetic waves with multiple polarization and/or propagation direction modes, preferably in the form of laser waves, are modulated by means of force-responsive devices such as amorphous quartz elements. The application of force or acceleration to the modulator creates a difference in frequency of two of the modes. That frequency difference is a function of the force or acceleration being measured. The two signals are combined and their difference is detected in a beat detector. In a preferred embodiment, the electromagnetic waves are developed in a ring laser operating with plural circular polarization modes. Preferably, each polarization mode exists in one of the counter-directional laser beams. The modulator is a quartz cylinder located in the laser cavity. The force is applied in the form of a torque tending to twist the cylinder about its longitudinal axis. The device provides a high degree of sensitivity and a wide range in the measurement of force and acceleration. The invention is described as it is used in gravimeters, pressure altimeters and pressure measurement devices.
TL;DR: In this paper, various theories of optical activity are applied to the differential Raman scattering of circularly polarized light by optically active molecules, and the one electron theory provides simple symmetry rules which enable the dissymmetric environments of functional groups with well-defined fingerprints in the Raman spectrum to be probed, and this could yield more detailed conformational and structural information than the o.r.d and c.d.
Abstract: The various theories of optical activity are applied to the differential Raman scattering of circularly polarized light by optically active molecules. In particular, the ‘one electron’ theory provides simple symmetry rules which enable the dissymmetric environments of functional groups with well-defined ‘fingerprints’ in the Raman spectrum to be probed, and this could yield more detailed conformational and structural information than the o.r.d. and c.d. bands of dissymmetrically perturbed chromophores.
TL;DR: In this article, the authors considered the coherence effects that arise from the sublevels of the scattering atom being not far from degeneracy, and used the density matrix formalism to derive the elements of the Mueller matrix for the resonance fluorescence process.
Abstract: The scattering redistribution function for the resonance fluorescence of polarized radiation in the presence of magnetic fields is established in terms of the Stokes parameter representation, as well as for a circular polarization basis. This analysis extends the treatment by the author of the resonance fluorescence problem where previously only the linear polarization basis had been considered. The redistribution function is treated in generality so coherence effects are included that arise from the sublevels of the scattering atom being not far removed from degeneracy. In the presence of weak fields, these coherence effects alter the frequency, directional and polarization properties of the scattering event. Use is made of the density matrix formalism to arrive at a description of the scattering process in terms of Stokes parameters. For the Stokes parameter representation, the procedure is given for deriving the elements of the Mueller matrix for the resonance fluorescence process. Both frequency dependent and frequency averaged redistribution functions are given for the general case applicable to any dipole transition. In addition for examples, the general equations are reduced to those applicable to the transition J = 0 to J″ = 1.
TL;DR: Gunn and Ostriker as mentioned in this paper suggested that the magnetic field in the Crab Nebula which causes relativistic particles to emit synchrotron radiation may be an oscillating 30 Hz electromagnetic field from the pulsar rather than a static field.
Abstract: IT has recently been suggested by Gunn and Ostriker1 and by Rees (paper presented at the IAU symposium 46 on the Crab Nebula, Manchester, August 1970) that the magnetic field in the Crab Nebula which causes relativistic particles to emit synchrotron radiation may be an oscillating 30 Hz electromagnetic field from the pulsar rather than a static field. Rees has shown that if this is the case, the nebula should show a component of circular polarization of order a few per cent in visible light. This is predicted to have opposite sense in the NW and SE regions of the nebula, supposing that the spin axis of the pulsar is in the direction of linear polarization.
TL;DR: In this paper, the Compton polarimeter was used to measure the circular polarization of the 482 keV γ-radiation of 181Ta and the 343 keV −1.5 −6.
TL;DR: In this paper, the effects of magnetic field on the circular polarization within the line FeI λ 6302.5 are investigated and the results on the V-reversal near the line centre are given for homogeneous magnetic fields.
Abstract: Magneto-optical effects on the circular polarization within the line FeI λ 6302.5 are investigated. Quantitative results on the V-reversal near the line centre are given for homogeneous magnetic fields.
Patent•
27 Jul 1971
TL;DR: In this paper, a frequency stabilized laser is disclosed in which active laser material exhibiting Zeeman effects is disposed in a resonant laser cavity to which an axial magnetic field is applied for producing Zeeman-splitting, and in which a feedback error signal is applied to adjust the frequency of laser oscillation.
Abstract: A frequency stabilized laser is disclosed in which active laser material exhibiting Zeeman effects is disposed in a resonant laser cavity to which an axial magnetic field is applied for producing Zeeman-splitting, and in which a feedback error signal is applied to adjust the frequency of laser oscillation. Optical means, including quarter-wave plates, are disposed in the laser cavity for insuring that the laser energy propagating in the laser material in a first axial direction is polarized in a first circular polarization sense only, as measured with respect to the direction of the applied magnetic field, and for insuring that the laser energy propagating in the laser material in the opposite axial direction is polarized in the opposite circular polarization sense only, as measured with respect to the direction of the magnetic field.
TL;DR: In this article, both forward Compton scattering from magnetized iron and transmission through magnetized irons have been used for the detection of circular polarization correlations in the β-decay of 203Hg, 199Au and 141Ce.
TL;DR: Radio telescope measurements of circular polarization and total flux of Jupiter at 13.1 cm wavelength were performed by as mentioned in this paper, and the results showed that the total flux was positively correlated with the rotation of the planet.
Abstract: Radio telescope measurements of circular polarization and total flux of Jupiter at 13.1 cm wavelength