noun
extraordinary ray
Technical term in optics, specifically in the context of birefringence. Contrasts with 常光線 (ordinary ray).
See also: 常光線
方解石に入射した光は、常光線と異常光線に分かれる。
Light entering calcite splits into an ordinary ray and an extraordinary ray.
常光線 is the ordinary ray in birefringence, obeying Snell's law, while 異常光線 is the extraordinary ray, which does not.
Compound of 異常 (abnormal, extraordinary) and 光線 (light ray). A calque of English 'extraordinary ray'.