High-precision cemented achromatic triplet lens made from three optically matched glasses (Crown–Flint–Crown configuration) such as N-BK7 and SF series, designed to correct axial chromatic aberration, spherical aberration, coma, and field curvature simultaneously across the visible spectrum (typically 400–700nm).

 Offers superior image quality and residual color correction compared to standard achromatic doublets. 

Each triplet features edge blackening to suppress stray light and ghost reflections, with optional broadband AR coating for maximum transmission. 

Widely used in high-resolution imaging systems, laser collimators, microscope objectives, and machine vision lenses. Custom diameters, focal lengths, and coatings available for OEM and R&D requirements.