N-BK7 Best Form Lenses, Uncoated/AR350-1700nm

N-BK7 Best Form Lenses, Uncoated/AR350-700/650-1100/1050-1700nm

Optimal-form spherical lenses are engineered to minimize spherical aberration while retaining standard spherical surfaces. The focal length of a spherical lens depends on the curvature radii of its front and rear surfaces, with different combinations producing varying levels of spherical aberration. By optimizing the curvature radius of each surface, optimal-form lenses minimize spherical aberration and enable diffraction-limited focusing under infinite conjugate conditions for focusing or collimation applications. For best focusing performance, the surface with the smaller curvature radius (steeper curve) should face the collimated light source.

Tuniu optimal-form lenses are manufactured from high-grade N‑BK7 borosilicate crown glass. As a widely used optical material, N‑BK7 delivers excellent optical performance at a cost-effective price. It features high uniformity, low bubble and inclusion content, and good machinability, making it ideal for visible and near‑infrared applications. N‑BK7 serves as a practical alternative to UV fused silica when high ultraviolet transmittance and ultra‑low thermal expansion are not required.

Tuniu optimal-form lenses are available in a standard 25.4 mm diameter, offered in uncoated and double‑sided anti‑reflection (AR) coated versions. AR coatings are optimized for 350–700 nm, 650–1100 nm, and 1050–1700 nm wavebands, effectively reducing single‑surface average reflectivity to below 0.5% and enhancing transmittance. Any diameter and focal length of plano‑convex lenses can be upgraded to optimal‑form configurations for superior performance across diverse applications. For custom specifications, please contact our technical support team.

Parameters

Model

N-BK7 Best Form Lenses, Uncoated/AR350-700/AR650-1100/AR1050-1700 nm

Mounted in SM1 Lens Tube/Unmounted