Plano-concave lenses focus light into a point. Its characteristic is that the focal length is positive, one side is flat, and the other side is convex. Commonly used for aiming and focusing of monochromatic light sources. When in use, face the concave surface towards the incident light.
Jingsheng Optoelectronics offers uncoated and AR-coated plano-concave lenses. AR coating options include UV, VIS, NIR, and SWIR. Germanium, silicon or zinc selenide substrates are suitable for infrared applications, and fused silica is suitable for ultraviolet applications.