N-BK7 plano-convex lenses optimized for focusing and collimating visible and near-IR light beams. The most economical choice for general-purpose imaging, beam focusing, and optical systems operating in the 350-2000nm range.
| Material | N-BK7 (Nd = 1.5168, Vd = 64.2) |
| Transmission Range | 330 - 2,100 nm |
| Diameter Range | 3mm - 150mm |
| Focal Length Range | 5mm - 5,000mm |
| Surface Quality | 40-20 / 20-10 (MIL-PRF-13830B) |
| Surface Flatness | lambda/4 @ 632.8nm (test plate) |
| Centration | < 3 arc min |
| Coating | BBAR / AR @ specific wavelength / Uncoated |
Parameter Reference Guide
Typical Standard capability — available as shown
Available Alternative options exist — request quotation
Custom Per your drawing — quote after review
Subject to Review Depends on project specifics
Select the optimal optical material based on your wavelength, power, thermal environment and mechanical requirements.
Coatings are engineered around your specific wavelength and operating conditions.
We optimize specifications to match your system requirements — not over-specify. Tighter tolerances increase cost without always improving system performance. Typical manufacturing capabilities:
Every component undergoes 100% inspection before shipment with full documentation including interferometer reports, spectral curves, surface quality images and dimensional data.
Orientation: For focusing a collimated beam, place the curved surface toward the collimated beam (longer conjugate). This minimizes spherical aberration for a singlet lens.
Chromatic aberration: BK7 singlet lenses have significant chromatic aberration. If your system operates across a broad wavelength range and requires sharp focus at all wavelengths, consider achromatic doublets instead.
f-number limit: For f-numbers below f/4, spherical aberration becomes significant in singlet lenses. Consider aspheric lenses for tighter focusing.
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Specification Parameters
Typical Specifications shown on this page are standard capabilities. Available Options include alternative materials and coatings. Custom Specifications are available per your drawing. Requirements beyond standard capability are marked Subject to Engineering Review.
Upload your drawing or specifications. Our engineering team will review and respond within 1 business day.
When requesting a quote for this product, please specify the following parameters to help our engineering team provide an accurate quotation:
Not sure about specifications? Upload your drawing and our team will assist with engineering review.