noun
optical axis (of a lens, spherical mirror, etc.)
In geometrical optics, the line passing through the center of curvature and the vertex of a lens or mirror.
レンズの光軸を合わせる。
Align the optical axis of the lens.
noun
In crystal optics, the direction along which no birefringence occurs. Also called 光学軸.
See also: 光学軸
方解石の光軸方向では複屈折が起こらない。
Birefringence does not occur along the optic axis of calcite.