Biconcave Lens

Biconcave lenses have concave surfaces on both sides, thin in the middle and thick edges, used to increase the divergence of converging light. A negative focal length causes parallel incident light to diverge outward. The two sides have equal curvature radii and are used for beam expansion and projection. Applied in optical components, laser systems, thermal imaging in infrared optics, and sensitive components in high-energy detectors.