Sapphire and glass ball lenses Ball lenses have very low spherical aberration and so focus and collimate light very accurately; a sapphire ball has only 23% of the aberration of an equivalent BK7 planoconvex lens over the same aperture. Ball lenses are available economically at very high precision and are simple to mount. Sapphire can be used from 170nm to 5.3µm and has exceptional hardness, strength and temperature resistance. Ball lenses are ideal for focusing light into fibres, fibre coupling, emitters and detectors.
Knight Optical > Lenses > Ball lenses - BK7 Type Only UK and EU customers are charged VAT at 17.5%, customers outside the EU and EU customers based outside the UK who have a valid EU VAT number will not be charged VAT Bulk Discounts! Where (B) appears next to a price below, bulk prices are available, click the (B) button to view! PDF Part No. Focal length (mm) Material Diameter (mm) Back focal length (mm) Price Qty Buy LBB00701 0.734 BK7 1 0.234 £7.99 LBB011015 1.1 BK7 1.5 0.35 £7.99 LBB018025 1.83 BK7 2.5 0.58 £8.45 LBB0304 2.93 BK7 4 0.93 £8.99 LBB0406 4.4 BK7 6 1.4 £11.99 LBB0710 7.34 BK7 10 2.34 £21.45 Knight Optical > Lenses > Ball lenses - BK7 Type
Specification   Material: BK7 or Sapphire  Material Data: (see materials section)  Diameter: ± 2.5µm  Figure (spericity) : 1λ  Focal Length: ± 0.2% (<10mm) ± 2.0% (10-1000mm) ± 5.0% (>1000mm)  Centre Thickness: ± 0.35mm  Surface Quality: <40-20 scratch/dig (see quality section)
Specific requirements We can source Ball Lenses to any size, focal length or in other materials at short notice, so if your requirements are not listed please contact us by telephone/ fax or email: stockrequirement@knightoptical.co.uk