Plano‑concave

Plano-concave (flat-concave) is a common type of optical lens with the following characteristics: 1. Structural features: One surface is flat, and the other is concave, resembling a \"bowl\" shape. 2. Optical properties: It is a negative lens that causes incident parallel light to diverge. Its focal length is negative, and it is commonly used for beam expansion or correcting aberrations in optical systems. 3. Application scenarios: It is widely applied in laser collimation, fiber optic coupling, optical imaging systems, and beam shaping, particularly suitable for scenarios requiring divergent light or adjustment of beam angles. Due to its simple structure and relatively easy manufacturing, this lens is a commonly used component in optical design and experiments.