Polarisation of LightMacmillan and Company, 1874 - 129 páginas This book contains the substance of lectures on polarized light in the hope that they inspire interest in the study of optics. |
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Términos y frases comunes
analyser be turned angle of incidence axis bi-axal crystals bisect C+B+A centre circular polarisation circularly coincide complementary colours consequently crests crystal plate diaphragm difference of phase different colours direction of vibration double double refraction effect ether examined exhibit extinguished film Iceland spar images incident ray instrument intermediate lamina left-handed mean-line motion Nicol Nicol's prism oblique optic axes ordinary ray orthorhombic overlap pair parallel particle perpen perpendicular phenomena placed plane of incidence plane of polarisation plane of reflexion plane of vibration plane-polarised plate of quartz plate of tourmalin polar clock polariscope polarised light polarised ray polariser and analyser polarising angle position principal section produced quadrants quarter-undulation plate quartz plate rectilinear reflected ray refractive index retardation rhombohedron right angles right-handed rotation selenite silver plate Sodium periodate spectrum stauroscopic successive polarisation Suppose surface system of rings thickness tints tion traversing turned round uni-axal velocity wave length wedges
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Página 116 - ... and 90° the rings will be contracted and extended in opposite quadrants, until at 45° they are divided by two diagonals, on each side of which the colours are complementary. Beyond 45° the rings begin to coalesce, until at 90° the four quadrants coincide again.
Página 120 - And if A, A' be the complementary tints extinguished by the first combination QP alone, and B, B' those extinguished by the second Q, P, alone, then it will be found that the following pairs of tints are extinguished in the various images. Image. Tints extinguished. OOB, A OE B', A' EO B', A EEB, A' It is to be noticed that in the image OE the combination Q, P! has extinguished the tint B...
Página 63 - ... the colours descend, and when it is on the right of the same plane the colours ascend, the analyser being turned from left to right. " It has been determined that the ordinary ray, . both in positive and negative crystals, is polarised in the principal section, while the extraordinary ray is polarised in the section perpendicular thereto. It is also established that the index of refraction is inversely as the velocity of transmission. It follows from the above experimental results, therefore,...
Página 123 - But the main interest of these parts of the figure consists in this, that each of the triple overlaps is complementary to the fourth single image ; since the re-combination of all four must reproduce white light.
Página 63 - These definitions being premised, if a film of selenite is placed on the diaphragm with its intermediate section to the left of the plane of reflexion, the successive polarisation is direct or rigHt-handed ; if, on the contrary, it is placed to the right of that plane, the successive polarisation is left-handed. The ray polarised in the intermediate section is therefore the most retarded ; and as that section is considered to be equivalent to a single optic axis, the crystal is positive. " In one...
Página 25 - ... direction of the eye-piece which contains a Nicol or other analyser. The objects to be examined are to be placed on the diaphragm E. This instrument may be converted into another form, due to Norremberg, by placing a silvered mirror horizontally at H. The plate of black glass must be removed from the frame F, and a plate of transparent glass substituted for it, which must be so inclined that the light falling upon it shall be reflected at the polarising angle perpendicularly towards the horizontal...
Página 63 - ... axes; the line which bisects the smallest angle is called the intermediate section, and the line perpendicular to it the supplementary section; and the order of the colours depends upon the relative velocity of the two rays. In selenite the ray whose vibrations lie in the supplementary section is the slowest; in mica it is the swiftest. Hence these two crystals...
Página 6 - although there is reason to believe that in general" the orbits of a considerable number of .consecutive molecules may be similarly situated, yet in a finite portion of the ray there are a sufficient number of variations of situation to prevent any preponderance of average direction.
Página 61 - A plate of black glass, G, is fixed at an angle of 3° to the horizon. The film to be examined is to be placed on a diaphragm, D, so that the light reflected at the...
Página 64 - ... therefrom. The principal section is that which contains the two optic axes. If the film is placed on the diaphragm with its principal section inclined 45° to the left of the plane of reflection, the successive polarization is right-handed. The ray, therefore, polarized in the section which contains the optic axes is the one transmitted with the greatest velocity.