noun
plano-concave lens
A lens with one flat surface and one concave surface. Used in optics, often for beam expansion or correction.
See also: 平凸レンズ
平凹レンズは、平行光線を発散させるのに使われる。
A plano-concave lens is used to diverge parallel light rays.
A plano-convex lens, which has one flat and one convex surface, converging light instead of diverging it.
Compound of 平 (flat) + 凹 (concave) + レンズ (lens).