optic axis

American  

noun

Crystallography.

1. (in a crystal exhibiting double refraction) the direction or directions, uniaxial or biaxial, respectively, along which this phenomenon does not occur.

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optic axis British  

noun

1. the direction in a uniaxial crystal or one of the two directions in a biaxial crystal along which a ray of unpolarized light may pass without undergoing double refraction

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Etymology

Origin of optic axis

First recorded in 1655–65

Example Sentences

Bouty 5.97 Elsas Quartz—     along optic axis 4.55 P.J.

From Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3 "Electrostatics" to "Engis" by Various

The source of light—the filament of a Nernst lamp—was moved about in a plane 120 cm. distant from the eye and perpendicular to the optic axis.

From Clever Hans (The horse of Mr. Von Osten): A contribution to experimental animal and human psychology by Pfungst, Oskar

But this, I am convinced, was a mere delusion, for all rays of light falling in the direction of the optic axis must have been intercepted and reflected by the opaque capsule.

From The Mind of the Child, Part II The Development of the Intellect, International Education Series Edited By William T. Harris, Volume IX. by Preyer, William T.

By G. Tschermak it is divided into two classes, meroxene and anomite; in the former the plane of the optic axis coincides with the plane of symmetry, whilst in the latter it is perpendicular thereto.

From Encyclopaedia Britannica, 11th Edition, Volume 3, Slice 7 "Bible" to "Bisectrix" by Various

In the oceanic Decapoda the cornea does not completely close, but leaves a central aperture traversed by the optic axis.

From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 6 "Celtes, Konrad" to "Ceramics" by Various