easy site creator


Our technical experts are here to assist you. For optical solutions to suit your needs

Why Use Aspheric Lenses?

Aspheric lenses are used to correct spherical aberration where the converging light from a lens does not have a common focal point, resulting in a distorted image. Traditional spherical lenses cannot collimate light effectively because even small angles of incidence can produce spherical aberrations.
Although they usually serve a similar purpose in correcting aberration, there are several benefits in using aspheric lenses instead of multi-lens designs such as doublets and triplets. Aspheric lenses are lighter and use less material, they are typically easier to fit, are far easier to mass produce and therefore can be significantly cheaper than multi-lens alternatives.


Camera Imaging Applications

Lens elements, whether concave or convex, were originally only composed of surfaces that represented part of a perfect sphere. The problem with this is that there are situations where such combinations of ‘spherical’ lenses cannot project an image that is uniformly focused across the flat surface of the camera sensor. Aspherical lenses, where the curve of the lens element surface is no longer part of a perfect sphere, can be used to correct such focusing aberrations and therefore medium to wide aperture lenses now encompass aspheric designs as vital components.
Aspheric lenses are not restricted to 400-700 nanometre (visible) applications. There is now an increasing demand in custom aspheric lenses for use in the infrared spectrum encompassing materials such as germanium which is used in MWIR, 3-5µm, for thermal imaging. 

Custom Aspheric Lenses from Knight Optical

Knight Optical offers an extensive custom manufacturing service supplying cost-effective, bespoke optical solutions. We are able to produce custom aspheric lenses in a plethora of different materials and sizes. Over the last three decades Knight Optical has developed an industry leading reputation, having supplied aspheric components to small scale university laboratories to multinational camera equipment brands. We have several types of aspheric lenses available for custom production. These include the following:

Custom precision grade aspheric lenses: Custom precision grade aspheric lenses provide excellent performance over the NIR and VIS spectrums. Our custom range of precision aspheric lenses can be provided uncoated and single-layer AR coated to improve transmission as high as 98% at the desired wavelength. Custom AR coatings can be offered to meet your wavelength application.

Custom plastic aspheric Lenses: Custom plastic aspheric lenses are relatively cheap as they are mass-produced, moulded or pressed, plastic. The surface quality of our custom plastic aspheric lenses is worse than most conventionally polished lenses. Some of these custom plastic aspherics have moulded flanges for ease of assembly. We can provide custom plastic aspheric lenses at competitive prices with very low tooling charges.

Custom fire-polished aspheric lenses: We provide a full range of both custom thermally toughened aspheric lenses and custom un-toughened fire polished aspheric lenses. We also have a huge tooling inventory available for custom aspheric lenses with “no tooling charges” however if you require a custom aspheric lens to your specification we can provide with minimum tooling costs.

Custom aspheric lens sets: We also provide custom aspheric lens sets at reduced costs compared to individually priced lenses. These are ideal for laboratory and design use.

Custom diamond turned aspheric lenses: A range of custom diamond turned aspheric lenses in a range of infra-red materials is also available custom made to your specific requirement.

Our typical custom aspheric lenses capabilities:

Diameter 3mm to 200mm+
Focal Length 3mm to 1000mm+
Centration < 3 arc seconds
Surface Figure < 0.1 fringes
Scratch/Dig < 10:5
Coating Options AR Coated for UV/VIS/IR
Material Schott glass (or equivalent) 

More information on the achievable specifications for your individual application can be found by contacting our technical sales team. 

Stock Aspheric Lenses

Knight Optical offers three ranges of aspheric lenses available from stock.

Precision grade aspheric lenses: Knight Optical stocks precision grade aspheric lenses in diameters ranging from 3mm-9.4mm and focal lengths 2mm-18.4mm. Each of our precision grade lenses is single layer AR coated for the visible range, centred at 550nm.

Plastic aspheric lenses: Our cost-effective stock plastic aspheric lenses offer an affordable alternative. Some of these plastic aspheric lenses have moulded flanges for ease of assembly. Parts LAP3528, LAP3553 and LAP3536 are moulded with mounting brackets attached.

Fire polished aspheric lenses: Knight Optical stock a full range of both thermally toughened aspheric lenses and un-toughened fire polished aspheric lenses. Fire polished varieties are manufactured using a simple moulding process and are polished by heating just enough to melt the surface and allow surface tension to smooth out defects. Usually these lenses have a very large diameter compared with the focal length.

To learn more about how our Quality Germanium solutions can improve your application and your supply chain experience, contact our multilingual technical sales team

ISO Standard

Knight Optical is very proud to be certified for ISO14001 for Environmental Management and ISO9001 for Quality Management Systems. These certifications demonstrate our commitment to maintaining competence and reliability in the supply, metrology testing and inspection of our products.

ISO 14001: Environmental Management we strongly believe that all businesses should be mindful of their environmental impact and seek to manage this effectively in their day to day activities. Green energy, recycling, carbon footprints and other environmental issues are very real concerns and we feel it is important to demonstrate to our customers our commitment to minimising our environmental impact.

Knight Optical has adopted and been certified for ISO 14001: Environmental Management System to comply with our environmental obligations. Our EMS framework allows us to have a systematic approach to the way we handle the challenges brought on by our commitment to environmental standards.


ISO 9001: Quality Management Systems quality should be consistent and customers should expect the same high quality service and products every time they order from us. In being certified for ISO9001, we are able to constantly monitor the way we work and ensure a consistently high level of service. We have well defined and documented procedures to ensure consistency and allow for corrective measures to be quickly applied should faults be found.

Our ISO9001 procedures give our management a clear and concise picture of how the company is performing. This mechanism of reviewing goals and performance aids us in our efforts to push forwards and improve as our company grows.


At Knight Optical we pride ourselves on the quality of our products and service. Every component is individually tested by our highly skilled technicians in our state-of-the-art metrology lab to ensure all parts meet our high quality standards. Our metrology laboratory is well equipped with the latest optical measurement technology including our ZYGO Verifire interferometer for form and Trioptics OptiSpheric for focal length and radius testing. All our coatings are thoroughly tested on our Cary 5000 spectrophotometer with new UMA reflectance attachment.

For more information on our metrology and testing capabilities

Inside Knight Optical’s catalogue you’ll find details of the industries we serve as well as the many other services we can offer. It also showcases hundreds of our most popular products, supported by useful technical information, to help you choose the right part for your application.

Our 2018/2019 Catalogue

© Copyright 2020 Knight Optical- All Rights Reserved