Showing papers in "Journal of the Optical Society of America in 1941"
TL;DR: In this paper, the effect of a plate of anisotropic material such as a crystal on a collimated beam of polarized light may always be represented mathematically as a linear transformation of the components of the electric vector of the light.
Abstract: The effect of a plate of anisotropic material, such as a crystal, on a collimated beam of polarized light may always be represented mathematically as a linear transformation of the components of the electric vector of the light. The effect of a retardation plate, of an anisotropic absorber (plate of tourmaline; Polaroid sheeting), or of a crystal or solution possessing optical activity, may therefore be represented as a matrix which operates on the electric vector of the incident light. Since a plane wave of light is characterized by the phases and amplitudes of the two transverse components of the electric vector, the matrices involved are two-by-two matrices, with matrix elements which are in general complex. A general theory of optical systems containing plates of the type mentioned is developed from this point of view.
1,706 citations
TL;DR: The theory of anomalous diffraction gratings, which was developed some years ago, has been reexamined in order to visualize its physical meaning as mentioned in this paper, where each wave diffracted by a grating is identified through the component of its wave vector tangential to the grating.
Abstract: The theory of Wood’s anomalous diffraction gratings, which was developed some years ago, has been reexamined in order to visualize its physical meaning. Each wave diffracted by a grating is identified through the component of its “wave vector” tangential to the grating. Surface waves similar to those found in total internal reflection are included (§2). The amplitudes of these waves can be calculated by successive approximations (§3). One feature of the anomalies is connected with the infinite dispersion of spectra at grazing emergence (§4). Emphasis is put on the existence of polarized quasi-stationary waves which represent an energy current rolling along the surface of a metal (§5). These waves can be strongly excited on the surface of metallic gratings under critical conditions depending also on the profile of the grooves; secondary interference phenomena arise then in the observed spectra (§6). The connection of the quasi-stationary surface waves with the wireless ground waves is discussed (§7). A general formulation is introduced to discuss the significance of the approximation used (Appendix).
838 citations
TL;DR: In this paper, it was shown that any optical system which contains only retardation plates and rotators is optically equivalent to a system containing only two plates, one a retardation plate, and the other a rotator.
Abstract: The general theory developed in Part I is used to prove three equivalence theorems about optical systems of the type under discussion. We prove that any optical system which contains only retardation plates and rotators is optically equivalent to a system containing only two plates—one a retardation plate, and the other a rotator. We then prove an exactly analogous theorem for systems containing only partial polarizers and rotators. Finally, it is proved that the most general optical system which contains any number of all three types of plates is optically equivalent to a system containing at most four plates—two retardation plates, one partial polarizer, and one rotator.
457 citations
TL;DR: In this article, the authors examined the properties of a rotational retardation system with a large number of identical retardation plates, each of which is rotated with respect to the one preceding it through the angle ω.
Abstract: Reusch and Sohncke have examined the properties of a system containing a large number n of identical retardation plates, each of which is rotated with respect to the one preceding it through the angle ω. The product of n and ω must be equal to μπ, where μ is an integer. Under certain conditions this system is optically equivalent to a simple rotator. This system, which would be very difficult to examine by ordinary methods, is given a treatment which is completely rigorous and which is more general than any given heretofore.
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TL;DR: In this paper, the angular distribution of light scattered by haze was determined in two ways (1) by measuring the brightness at various angles of a searchlight beam at night, and (2) by detecting the brightness of the horizon sky at various azimuths for a moderately low sun and a cloudless sky.
Abstract: By means of a telescopic photometer measurements were made in daylight of b, the brightness of a large approximately blackbody at a distance d=3.2 km, and of h, the brightness of the sky just above the blackbody. For visual ranges v from 3.2 to 15 km the measurements agreed with the theoretical relations v=(1/β) log 1/η and β=(1/d) log (1/(1−b/h), where β is the atmospheric attenuation coefficient, and η is the threshold of brightness contrast, being 0.02 for the usual intensities of daylight illumination. It followed that the ratio of β to the attenuation of optically pure air was 277, 55.4, 27.7, 13.8, 5.54 and 2.77 for v=1, 5, 10, 20, 50 and 100 km, respectively. The angular distribution of light scattered by haze was determined in two ways (1) by measuring the brightness at various angles of a searchlight beam at night, and (2) by measuring the brightness of the horizon sky at various azimuths for a moderately low sun and a cloudless sky. The distribution was much the same for haze ranging from thin to thick. It showed pronounced forward scattering, over three-fourths of the light being scattered in a forward direction and less than one-fourth in a backward direction. Such a scattering distribution would occur from haze particles of various sizes, most of them being of dimensions greater than the wave-lengths of white light.
TL;DR: Using an optical pyrometer method, the thermal conductivity of tungsten has been found to vary linearly from 1.170 watts at 1100°K to 1.026 watts at 2000°K as discussed by the authors.
Abstract: Using an optical pyrometer method, the thermal conductivity of tungsten has been found to vary linearly from 1.170 watts/(cm2 K°/cm) at 1100°K to 1.026 watts/(cm2 K°/cm) at 2000°K. Similarly, the thermal conductivity of molybdenum has been found to vary linearly from 1.083 watts/(cm2 K°/cm) at 1200°K to 0.666 watt/(cm2 K°/cm) at 1900°K. Spectrographic analysis indicated only traces of impurities in samples of the two metals used in the investigation.
TL;DR: In this paper, an electron microscope having a resolving power of less than 50A has been built and used to examine photographic emulsions, showing very small particles of silver formed within silver bromide crystals when they are exposed to an intense light source.
Abstract: An electron microscope having a resolving power of less than 50A has been built and used to examine photographic emulsions. When photographic crystals are exposed to an electron beam, silver ions move within the crystals and metallic silver is produced. Also the crystals disintegrate, cracks and holes developing. Pictures have been made showing very small particles of silver formed within silver bromide crystals when they are exposed to an intense light source. Silver reduced from silver bromide by the common chemical developers has been found to have a filamentary structure rather than the “cokelike” form as previously believed. Physical development produces clumps of closely packed silver particles. The smallest photographic crystals (Lippmann crystals), when developed in the common developers, are converted into single threads or ribbons of silver.
TL;DR: In this paper, the authors used interpretable Zeeman patterns of 427 Ce II lines to check and extend the classification of Ce II, in which 3600 lines are now assigned to transitions between pairs of 316 levels.
Abstract: The light emitted by cerium atoms in magnetic fields up to 96,400 oersteds has been photographed at high spectrographic resolution over the range 2500 to 7000A Interpretable Zeeman patterns of 427 Ce II lines have been reduced, and from them g and J values have been determined for 280 levels These data have been used to check and extend the classification of Ce II, in which 3600 lines are now assigned to transitions between pairs of 316 levels The energy system of Ce II consists of two groups of levels which have not yet been connected Group I is believed to be the lower of the two by approximately 5000 wave numbers This group consists of levels arising from the electron configurations 4f26s, 4f25d, 4f26p and 4f3 Complete assignments of quantum numbers have been given to all levels in this group on the basis of Zeeman effect studies, combinations, intervals and intensities All terms have been assigned to electron configurations and parent terms Group II consists of energy levels believed to originate from the electron configurations 4f5d6s, 4f5d2, 4f5d6p, 4f6s6p, and others g values to 3 figures after the decimal are well established for many of these levels, but only a few levels are given L and S assignments, which are tentative Interactions among these levels are strong, and assignment of individual quantum numbers will probably have little significance Data are now available for complete tests of the g sum rule in a number of cases It is found to be exact in cases where all perturbing terms are known g values obtained from different lines for the same energy level are consistent to within 0003 unit on the average
TL;DR: Direct experiments with instillation of adrenalin and pilocarpin into the eye have shown that color sensitivity does change when affected by these sympathico- and parasympathico-mimetic substances, and it is also possible to account for the seasonal fluctuations of color sensitivity.
Abstract: Quite different indirect stimuli often produce similar changes in the color sensitivity of the eye. It was assumed that this similarity of effect is due to all these indirect stimuli being similar as to their influence upon the autonomic nervous system. Direct experiments with instillation of adrenalin and pilocarpin into the eye have shown that color sensitivity does change when affected by these sympathico- and parasympathico-mimetic substances. In the light of the dependence of color vision on the autonomic nervous system, it is also possible to account for the seasonal fluctuations of color sensitivity recently described in special papers.
TL;DR: In this paper, a procedure for determining the refractive indices of black materials with uncertainties in the third decimal place is presented. But it is only on freshly ground and polished surfaces.
Abstract: On the basis of Brewsterian angle measurements, a procedure is here outlined which yields refractive indices with uncertainties in the third decimal place. Since “bulk” refractive indices are desired, it is shown that the errors due to surface films may be eliminated by making measurements only on freshly ground and polished surfaces. Attention is directed to applicability of this procedure when the refractive indices of black materials are to be determined.
TL;DR: In this article, it was shown that the velocity of light is a constant as nearly as we can measure it at present, and the final result of 2895 observations was given as 299,776±14 km/sec.
Abstract: Improvements in the apparatus formerly used include the use of an eleven-stage electron multiplier tube, the control of the transmitter frequency by the laboratory standard, the substitution of a 1000-watt water-cooled mercury arc for the light source, a new type of Kerr cell, changes in the mirror supports and base line measurements, and the use of an automatic recorder. The apparatus has been completely rebuilt and converted to a.c. operation. The optical system has been changed to permit simpler measurements of the path difference, and electrical circuits have been devised to smooth out the fluctuations due to voltage variations and other causes.Group velocity is discussed as a correction factor in this and previous measurements. The correction is shown to amount to as much as 7 km/sec. in some cases. Electron transit time is shown to be a limiting factor for this method of measuring the velocity of light. The final result of 2895 observations is given as 299,776±14 km/sec. This includes a group velocity correction and should not be compared with previous results without taking this into consideration. The conclusion is reached that the velocity of light is a constant as nearly as we can measure it at present.