Laser quality diverging and expanding lens for high energy laser and performance-critical applications; 350 nm – 2 μm. Well-suited to a wide range of light expansion tasks in the visible and near-infrared, these N-BK7 equi-concave lenses are precision polished to ensure best wavefront quality and low scatter. They are offered with a large selection of optional high energy AR coatings.

Laser quality N-BK7 bi-concave lenses use their negative focal length to diverge or expand light in laser beam expanders, optical character readers, viewers, and projection systems for high energy and performance-critical applications.  N-BK7 is the preferred optical glass for quality optical components in the visible and near infrared, offering excellent transmission, as well as good optical and mechanical properties.

These bi-convex lenses possess two concave surfaces of equal radii.  Like their convex counterparts, they are best corrected for diverging a converging beam, but can also be used at infinite or near-infinite conjugate ratio when compact optical systems are required, as in the construction of beam expanders.  High surface quality and surface accuracy ensure best wavefront quality, minimized scattered light and excellent laser damage threshold.  Contact CVI Laser Optics for custom dimensions, focal lengths and OEM capabilities.
• λ/10 surface figure, 10-5 surface quality 
• Negative focal lengths from 5 to 150 mm
• Diameters from 5 to 25.4 mm
• Wide selection of laser line and broadband low-loss, high energy AR coatings