Ball and half-ball lenses

06 Apr 2023

Ball lenses, as the name suggests, are completely spherical lenses which are commonly used to improve the coupling of light in and out of fibres, detectors and emitters. Due to their effectiveness, often small size, and relatively low cost, ball lenses have maintained their position within a wealth of industries.

Knight Optical has a stock catalogue of competitively priced ball and half-ball lenses manufactured from a variety of materials including BK7, UV fused silica, sapphire, and cubic zirconia. These range from 0.6mm to 10mm in diameter, with AR coated options available with enhanced performance over certain wavelengths.

Below are our product specifications:

Material: BK7 or equivalent, Sapphire, Ruby , Quartz, Cubic Zirconia, LASFN-9, UVFS, S-LAH78

Diameter: ± 2.5µm

Ball Sphericity: 0.625 µm

Focal Length:

± 0.2% (<10mm)

± 2.0% (10-1000mm)

± 5.0% (>1000mm)

Surface Quality: < 40-20 scratch/dig

If our stock components do not match your requirements, Knight Optical is renowned for its custom solutions, offering high quality products and service to ensure you receive optical components that are fit for purpose. For custom ball lenses, this includes offering different dimensions, alternate materials, and the addition of a coating.

Different material options include spinel, alumina 99.9% & 99.5%, zirconia yttria, silicon nitride, tungsten carbide, steel, optical glass, and Zerodur.

Find our typical custom capabilities below, however please note that tolerances are also dependent on the grade of ball lens:

Diameter: 0.15 to 30mm+

Diameter tolerance: < 25.40µm

Ball sphericity: < 5µm

Surface roughness: < 5µm

All ball and half-ball lenses are tested within our metrology and QA departments to ensure they conform to their specifications. Utilising our Starrett AV300 coordinate measuring machine for these miniscule optical components we can verify the diameter and sphericity of the ball lenses.  

Read our blog post on ball lenses for further information on the benefits of these simple optical components and the different materials to choose from.

Contact our UK and US sales team for further information and help with your enquiries.

Europe, UK, Asia & RoW:

Email:  info@knightoptical.co.uk 

Telephone: +44 (0)1622 859444

USA & Canada:

Email:  usasales@knightoptical.com

Telephone: +1 401-583-7846