Knight Optical

Request Information

About Knight Optical

About us

Established almost 30 years, Knight Optical has become recognised as a trusted name in quality precision optical component design, consultancy and manufacturing. Now a global leader in optical solutions, with offices in the United Kingdom and the USA, our goal is to continue building our reputation by delivering the superior optical products our customers demand, and the quality of service and personalised support they deserve.

Knight Optical is a worldwide supplier to a variety of industries. These include the scientific, defence, security, aerospace, medical & biotech, pharmaceutical, optoelectronic, engineering & manufacturing, entertainment, education, laser, and oil & gas industries, amongst many others.

Quality Assurance

As a customer of Knight Optical, you will benefit from exceptional commitment to quality in all respects. Your individual specifications are vitally important to us, which is precisely why pre-despatch testing is rigorous to the highest degree. Our onsite quality assurance and metrology departments take personal responsibility for ensuring each and every component that leaves our premises does so in strict accordance with customer requirements.


Knight Optical is ISO9001:2015 and ISO14001:2015 UKAS accredited. These ISO standards are stringently adhered to throughout our entire organisation. You will find our professional workforce highly skilled and qualified. Our technical specialists are able to accurately interpret drawing specifications and are trained in drawing quality standards to ISO10110, BS4301 and MIL-SPEC, amongst others.

Turnaround and Value

Our customers appreciate not just our technical capabilities and quality commitment, but also our understanding of the importance of budget and timescale. By maintaining our operation at a manageable size, we have been able to remain competitive, so that our customers can do the same.

Custom Optical Solutions

We welcome the challenge of creating custom solutions for any of your optical innovations or challenges. Any specification, any material, any scope; you can be fully assured that whatever your unique requirement, you can enjoy complete trust in the true expertise of our respected optical component design and manufacturing specialists.

Stock Optical Components

Knight Optical is a global leader in stock optical components. We offer more than 3,000 products ready for despatch and available for next day delivery. So if you have an urgent requirement, you can consider it met by Knight Optical.

Partnerships and Support

Building partnerships with our customers is a key priority for Knight Optical. Our multilingual sales and technical support specialists are at your service at all times. We are committed to doing all we can to support your objectives and to understanding not just your requirements, but your reasoning behind them. This we have found a proven strategy in buoying the success of our customers.


What's new

About Knight Optical


Our stock and custom Domes are available for a range of underwater Remotely Operated Underwater Vehicles (ROVs), Pyranometers and high-pressure Viewport applications, and are commonly specified for high-end imaging applications due to their excellent Transmitted Wavefront Error (TWE) benefits.

Our high-quality material options include the following:

  • BK7
  • Silicon
  • Sapphire
  • UV Fused Silica
  • Acrylic.

Alongside our vast range of stock (available for immediate order online), we also offer custom-made Domes in options up to 190mm in diameter. For projects requiring larger sizes, we also supply large acrylic-moulded and diamond-turned Domes, which are available in diameters up to 300mm.

Find out more about our stock and custom domes by clicking the link below.



We supply a wide variety of Apertures, including Pinholes, Slits and Iris Diaphragms in sprung and stainless-steel leaves for beam-shaping applications or saturation of a detector.

Pinhole varieties are laser drilled from 0.5µm to 1000µm apertures on 302 stainless-steel and are available mounted in a range of standard sizes or as unmounted foils. Supplied in standard or custom-made sizes, our Slit Apertures are laser drilled from 5µm to 200µm in width.

As well as a range of 86 stock components, we also offer custom-made Apertures tailored to your requirements. Furthermore, we also offer motorised varieties as well as fully closing types, in sizes ranging from 0.7mm to 225mm.

Read more about our stock and custom Aperture range by clicking the link below.



Used in Gunsights, Ranging Systems and Scopes, our premium-quality Eyepiece and Stage Graticules are processed using a vacuum metal deposition and etching or photolithographically processes.

Knight Optical’s Eyepiece and Stage Graticules can be manufactured to custom patterns – from scales, crosshairs, protractors and grids – and can be applied to a wide range of substrates, including plastics, IR/ UV crystals and metals.

Most Knight Optical Eyepieces are available with a standard 19mm and 21mm eyepiece. Mounted Reticule Assemblies and Stage Graticules for sample measurement and calibration in microscopy are also available.

All Knight Optical Reticules are meticulously measured for quality using a Starrett AV300 video imaging test instrument in our in-house state-of-the-art Metrology Laboratory.

To learn more and browse through our stock of over 24 stock Reticules, click the link below.



Here at Knight Optical, we stock a vast array of Plate and Cube Beamsplitters, including square Plate Beamsplitters in sizes up to 300mm as well as Polarising and Non-Polarising Cubes, from 3mm to 50mm.

Known for their highly accurate R/T% values, our Beamsplitters are available in a range of split ratios, including (T%/R%) 50/50, 60/40, 70/30 and 90/10. Also available are visible and near-infrared (NIR) wavelengths, including Telecom 1050-1700nm on Plates, with high-quality quarter-wave substrates.

What’s more, our Beamsplitters benefit from high-quality Broadband Anti-Reflection (BBAR) coatings on the rear of plate to eliminate secondary reflections and provide your application with ultimate accuracy. For complex NIR wavelengths, we also offer Dielectric and Hybrid coatings on Beamsplitter Cubes.

For projects seeking quick turnaround times, we also stock pre-coated sheets which are available for custom sizes at short notice.

To guarantee compliance with your specification, all Beamsplitters are measured in our in-house state-of-the-art Metrology Laboratory using our Cary spectrophotometer – equipped with a Universal Measurement Attachment (UMA).

To learn more about our custom options and browse through our stock range of over 85 Beamsplitters, please click the button below.



Used for altering divergence on incident light across a range of imaging and optical sensing applications, Diffusers are available as custom-made options or from our wide range of over 46 stock Diffuser options. For dimensions and shapes not listed on our website, we also stock sheets available for custom sizes at short notice.

Supplied with a 40-micron finish or a custom grit size (down to 3µm), our Diffusers are available in UV and NIR material options, including White-Flashed Opal in 3.3mm at 6mm-thick, 0.3mm PVC screens and Optolite™ HSR Plastic Diffusers, acrylic with controlled transmission values, Anti-Newton etched glass (up to 450mm square), plus more.

View our full product range and find out more about our custom-made Diffusers by clicking the button below.



We offer a range of Polarisers for UV, visible and NIR applications. As well as over 98 stock Polariser options available on our website – including a large sheet range (which can be cut to custom sizes at short notice) – we also offer Polarisers as a custom-made item, tailored to your requirements.

Our visible grade sheet Linear Polarisers include HN22, HN32, HN38, HN38S, HN42 and HN42HE options, either as original 3M grades (or replacement material), with sizing options up to 36×22″ in various laminations and thickness. Meanwhile, our UV-NIR sheet Polarisers come in HR and HNP’B grades.

Furthermore, we also provide Circular HNCP37 original 3M Polarisers (and replacement materials) – in left- and right-handed types and in a range of lamination options and finishes – as well as Crystal and Cube Polarisers.

Learn more about our range of Polarisers by clicking the button below.



Knight Optical offers an assortment of retarders for use in UV, visible and NIR wavebands. As well as over 70 stock Quartz and Mica options and over 20 plastic-type Retarders available via our website, we also offer a range of custom-made solutions. Furthermore, for projects seeking quick turnaround times, we stock sheets available for machining to specific sizes at short notice.

Our Retarder range includes Mica and Quartz Retarder Plates in a range of wavelengths from 400-1500nm, in standard 25mm-diameter laminated plates, and Achromatic Retarders made from quartz crystal in wavelengths from 450-1650nm.

Read more about our Retarder range by clicking the button below.


Metal Optics

Our Metal Optic solutions are commonly specified for flat, concave and parabolic reflector applications in materials such as copper, aluminium, brass, nickel and stainless steel.

Suitable for use in solid-state lasers ranging from 400nm to 1.5 µm, Metal Optics are offered in a range of visible and NIR coatings. What’s more, we are capable of meeting complex geometry requirements, providing you with a full turnkey solution for your optical needs.

Provided as custom-made components only, Knight Optical’s variety of Metal Optics features a surface roughness of less than 20 angstroms and surface accuracy to quarter-wave.

Find out more about our Metal Optics by clicking the button below.


Optical Flats

Available in double-sided or single-sided polished options for high accuracy front surface mirrors, our Optical Flats are commonly specified as reference surfaces for the testing of components.

Standard materials include Quartz, UV Fused Silica and Zerodur, in diameters of up to 500mm and lambda/20. Not only do we hold stock of over 35 standard Optical Flats, but we also offer custom-made solutions to meet the needs of your project. What’s more, we can provide a rework and calibration service for Optical Flats.

Our Optical Flats are tested using our Zygo Verifire XPZ interferometer system – fitted with the latest Mx® software – and are supplied certified in a quality wooden box.

We also offer a stock range of over 15 Monochromatic lights, in freestanding or benchtop options.

Learn more about our Optical Flats by clicking the button below.


Sapphire Optics

Known for their ability to withstand harsh environments, our Sapphire Optics are available in a variety of options. These include UV Grade fluorescent-free Windows and Lenses for use at 150nm to 5.5µm, Random-Cut Grade Windows, up to 320mm diameter x 50mm-thick, C-Cut and Z-Cut – and for non-birefringent critical applications – Domes for high-pressure UAV applications and small 5mm diameters x 0.5mm, or thinner, wafers.

Alongside our stock range of over 39 standard Sapphire components, we also offer custom-made solutions, enabling you to specify the dimensions, tolerances, coatings (including Broadband Anti-Reflection [BBAR]), plus more.

With a <60/40 Scratch/Dig surface quality, our Sapphire Optics are designed for ultimate durability.

Find out more about our Sapphire Optics by clicking the link below.


Germanium Optics

For use between 2µm to 14µm and commonly used in thermal imaging applications, our high-density Germanium Optics are regularly specified for their exceptional quality.

Knight Optical’s stock Germanium range consists of Lenses, Prisms, Blanks and Windows (including Diamond-Like Carbon/Anti-Reflective-coated [DLC/AR] options for 7-12 µm). For projects requiring tailored solutions, we also offer our Germanium Optics as custom-made components, enabling you to specify the dimensions, coatings and tolerances best suited to your application.

Here at Knight Optical, we offer a range of Anti-Reflective (AR) and Diamond-Like Carbon (DLC) coatings to cover 2-14 µm spectrums, as well as Hydrophobic and Petrochemical coatings.

Included in our Germanium range are Windows and Wedge Prisms up to 300mm diameter, diamond-turned and conventional polished Aspheric, Spherical and Meniscus Lenses, in up to 200mm diameters, as well as small 5mm diameters in diced squares and rectangles.

With a <40/20 Scratch/Dig surface quality, Knight Optical’s Germanium Optics are unparalleled in quality and boast high durability.

Learn more about our Germanium Optics by clicking the button below.


Z-Cut Quartz Optics

Our Z-Cut Quartz Optics are available in left- and right-handed options, in up to 150mm diameters. We also offer Prisms and Polarisers in a range of sizes to meet most applications, as well as Spherical and Meniscus Lens options.

As well as over 20 standard Z-Cut Quartz stock components available on our website, we also have the capability to provide custom-made components to accommodate the requirements of your project. This service enables you to specify dimensions, coatings (such as Broadband Anti-Reflection [BBAR]), and much more. Furthermore, if you’re looking for a specific size at short notice, we are able to machine our stock Z-Cut Quartz Windows for quick turnaround times.

With a <40/20 Scratch/Dig surface quality, our Z-Cut Quartz Optics are manufactured to the highest quality. What’s more, our Z-Cut Quartz’s flatness and Transmitted Wavefront Error (TWE) is better than quarter-wave and parallel to 3 arcminutes.

For more details on our Z-Cut Quartz Optics, please click the button below.


Silicon (Si) Optics

Used in thermal imaging applications at Mid-Wave Infrared (MWIR) from 3µm to 5µm, Silicon is an ideal material for detecting black body temperature of 700K.

As well as a wide range of stock components available on our website, we also provide custom-made Si Optics, tailored to meet your application’s demands. With this customised service, you can specify the dimensions, tolerances and coatings that meet the needs of your application.

Here at Knight Optical, we offer a range of coatings to meet the needs of a wide range of applications, including a variety of Anti-Reflective (AR) and Diamond-Like Carbon (DLC) coatings to cover 2-5µm spectrums, as well as Hydrophobic coatings.

Our Si range consists of Windows and Wedge Prisms, in up to 300mm diameters, diamond-turned and conventional polished Aspheric, Spherical and Meniscus Lenses, in up to 200mm diameters, and small 5mm diameters in diced squares and rectangles.

With a <40/20 Scratch/Dig surface quality, our Si Optics are manufactured to the highest quality possible.

To find out more about our Si offering, please click the button below.


Calcium Fluoride (CaF2) Optics

Knight Optical supplies a wide range of CaF2 Windows and Lenses for a variety of applications such as Vacuum Ultraviolet (VUV) Detector applications.

With over 58 standard Window and Lens CaF2 components accessible via our website, Broadband Anti-Reflection (BBAR) coatings available from 200nm to 10µm and diameters up to 200mm with quarter-wave flatness, Knight Optical is the specifier’s number one choice for CaF2 Optics.

With a plethora of components to meet the needs of all applications including diamond-turned Aspheric and Meniscus Lenses, traditional spherically polished Lenses as well as Raman/Standard and UV Grades, our CaF2 Optics have the capability to meet all applications’ requirements.

Furthermore, with a <40/20 Scratch/Dig surface quality, our CaF2 Optics are unparalleled in quality, providing you with on-spec components, that are designed to last.

To read more about our CaF2 Optics, please click the button below.


Magnesium Fluoride (MgF2) Optics

For deep UV applications down to 100nm and IR applications to 7µm, Knight Optical offers a range of high-quality MgF2 Optics in custom-made options, or from our wide variety of stock components.

With Broadband Anti-Reflection (BBAR) coatings available from 1-7µm, Windows in up to 50mm diameters and 5mm-thick and flatness to quarter-wave, our range of MgF2 Optics meet an array of application requirements.

With a <20/10 Scratch/Dig surface quality, our MgF2 Optics are unparalleled in quality, providing you with reliable on-spec components every time.

Find out more about our MgF2 Optics by clicking the button below.


Zinc Selenide (ZnSe) Optics

Knight Optical’s premium ZnSe Optics are suitable for a wide range of IR wavelengths – from 0.6µm to 21µm – and are commonly specified for a variety of applications, including Forward-Looking Infrared (FLIR) Radiometers and CO2 laser applications.

Not only do we offer a stock range of over 22 standard ZnSe Lenses and Windows, but we also offer custom-made components to meet millimetre-perfect specifications, including mounting options and Broadband Anti-Reflection (BBAR) coatings.

Our range includes Windows in diameters from 5-100mm, diamond-turned Aspheric and Meniscus Lenses – as well as traditional spherically polished ZnSe Lenses – Beamsplitter options (in square and rectangular varieties) and small 5mm diameters to larger 100mm diameters.

What’s more, a <60/40 Scratch/Dig surface quality means our ZnSe Optics are unparalleled in quality, providing you with industry-leading components.

Learn more about our ZnSe Optics by clicking the button below.


Infrared (IR) Filters

Knight Optical offers a range of IR Filters including Bandpass Filters to 20µm, IR Longwave and Shortpass Filters, Neutral-Density (ND) Filters, Gas-Band Filters as well as Semiconductor Filters.

We also offer a variety of diameters in our IR Filter range, including small sizes down to 2x2mm (which are commonly used for detectors) and in square or rectangular varieties.

Alongside a large range of stock Filter options available offline (for order via a Technical Sales Adviser), we also offer IR Filters as custom-made components made to your specifications.

Discover more about our IR Filters by clicking the button below.


Other Infrared (IR) Optic Solutions

We also offer a variety of other stock and custom-made Lenses and Windows in IR material solutions, including:

  • Barium Fluoride (15 online stock Window options)
  • KRS 5N (three online Window options)
  • Potassium Bromide (seven online window options)
  • Sodium Chloride (four online Window options).

Find out more about our IR Optic Solutions by clicking the button below.


Optical Tools and Accessories

Knight Optical offers a wide variety of tools and accessories, including:

  • Filter storage boxes
  • Vacuum pick up tools and systems (including accessories)
  • Cleaning and packing cloths
  • Surface blowers and brushes
  • Optical cleaning agents
  • Lab gloves and finger cots.

Discover our Optical Tools and Accessories range by clicking the button below.



As well as a vast range of Tools and Accessories, we also offer an array of Optomechanical components and accessories in a variety of mounting and positioning options. These include:

  • Camera filter holders, designed to fit standard 25mm diameter filters with M25.5 and M30.5 thread – ready for fitting to Tamron, Fujinon and Sony camera lenses
  • Self-centring component holders
  • Adjustable component holders
  • Fitted component holders
  • Breadboards and bases up to 800mm square
  • Mounting posts
  • Post holders
  • Post clamps
  • Post thread adaptors.

Discover our range of over 200 Optomechanics by clicking the button below.


What's new

About Knight Optical


Optical Design and Consultancy

Known for their sound advice, our team of highly skilled Technical Sales Advisers are well-versed in optical design and possess the skills to assist with optical-related queries, no matter the complexity.

Our qualified team have the capabilities to:

  • Evaluate your design’s tolerance and performance
  • Offer help and advice in developing custom optics
  • Ensure your design’s offer is feasible and provides excellent value
  • Create 3D models and drawings (All drawings are to ISO standards).


Following production, our in-house Metrology Technicians test your components to ensure they wholly comply with your specifications. Working from our state-of-the-art Metrology Laboratory, our well-informed team of Technicians guarantee your optics are on-spec with millimetre-perfect precision. This, combined with our plethora of optical knowledge, ensures that you can rest assured that your component will benefit from a seamless process; right from the manufacturing stage through to delivery.


Optical Finishing and Processing

All our optical components are manufactured to the highest standards possible, and to ensure we meet the requirements sought by your project, we offer a vast range of optical finishing and processing options, including:

  • Diamond turning
  • Prism grinding
  • Reworking your materials
  • Screen printing
  • Glass blowing
  • Lens polishing
  • CNC grinding
  • Edging (stock windows and lenses etc.)
  • Etching
  • Cutting service
  • Precision lapping
  • CNC dicing
  • Laser cutting (of plastics)
  • Sandblasting
  • Drilling
  • Precision polishing
  • Water jet cutting
  • Laser cutting
  • Toughening
  • Sub-assemblies.



Our stock sheet polarisers are offered in CAB-laminated and AR-coated glass-laminated sheet options. With a wide-ranging substrate offer, standard material options include acrylic, polycarbonate and glass.

If you require assistance with lamination, please do not hesitate to contact a member of the Technical Sales Team on +44 01622 859444.

Optical Coatings

Optical coatings range from the UV to visible and IR wavelengths, ranging from 185nm in the UV to over 20µm in the IR spectrum.

Our Metrology Technicians have the capabilities to perform a range of reflection and transmission measurements, at any requested angle of incidence (AoI). The coatings that can be tested for R/T% values are single and multilayer coatings (both polarising and non-polarising), including broadband, V-coat, polarising, metallic and dielectric.

Our vast range of anti-reflection (AR) and mirror coated custom optics include:


Optical Sub-Assemblies

As well as our custom-made optical components, we also offer a mounting option, in which your optics can be applied to housings and fixtures to meet the precise needs of your specification.

Our Technical Sales Advisers are on hand should you require guidance on optical sub-assemblies.

What's new

About Knight Optical

At Knight Optical, quality control is of utmost importance and taken extremely seriously. We understand that if a drawing has a tolerance, surface specification and material type then the information is there for a reason. We will always ensure that all aspects of your drawing and specification are adhered to. We also visually inspect 100% of parts to ensure every part you receive meets quality standards.

In order to meet our customers specifications, Knight Optical has invested a substantial amount of time and resources into developing an impressive metrology and quality assurance department. This is run by highly qualified staff, who are trained on the latest state-of-the-art metrology instruments. This, combined with our professional business relationship, ensures you receive an excellent service you can trust.

Knight Optical have a strict quality system. Our management systems, standards and guidelines all comply with ISO 9001:2015 standard. We also work to the following standards:

  • ISO10110 – Optical drawing standards
  • BS4301 – 1991 Preparation of drawings for optical elements and systems
  • MIL-C-14806A Coating, reflection reducing for instrument cover glasses and lighting wedges
  • MIL-G-174B Optical Glass

All test data is recorded at Knight Optical and can be provided in a number of different formats, this includes a Knight Optical metrology report which clearly presents all the data in one table. Data can also be presented in the original formats produced by the respective software for each instrument.

Our trained technical inspection technicians
Our most valuable asset is our staff. We have a team of highly trained technicians checking all optical components to ensure they fully comply to drawing specifications and Knight Optical’s high quality standards.

Zygo Verifire XPZ + Interferometer System

  • Provides fast low uncertainty form measurements of flat or spherical surfaces, and transmitted wavefront measurement of optical components and assemblies
  • Interferometric Radius Slide (IRS) system combines linear measurements provided by
  • the encoded rail and cavity measurements made by the interferometer to give highly accurate radius of curvature readings
  • ZYGO’s proprietary Mx® software offer a wide range of operational features and data analysis tools for unmatched measurement capability and reporting

Varian Cary 5000 (+ UMA attachment)

  • Measures reflection, transmission and optical density of coatings and materials
  • Scan ability from 175nm-3200nm
  • Measures OD up to 4 Abs
  • State-of-the-art UMA attachment used to measure transmission, reflection of optical components (including complex cube beamsplitters and polarisers) at multiple angles of incidence
  • Measures S and P polarisation

Agilent 660 FTIR Spectrophotometer

  • Measures transmission of IR materials and Coatings
  • Scan range ability from 1.67µm – 44.44µm

Starrett AV300

  • Non-contact dimensional metrology for complex component such as graticules, metal assemblies and apertures
  • Measurement data for parameters including concentricity, corner radii, angles, and facet widths (Fresnel lenses)
  • Automated processes for inspection of large volumes of optics
  • Automated Vision System – bright and dark field illumination providing robust measurement for even the most challenging surfaces
  • Resolution down to 0.0001mm or 0.1µm.
  • Accuracy over the travel of the stage to within 4.5µm (dependent upon magnification)
  • 12:1 motorised zoom giving a wide range of enlargement from 25-230x magnification

Trioptics Optispheric

For testing lens parameters such as:

  • Effective focal length (EFL)
  • Back focal length (BFL)
  • Radius of curvature (ROC)
  • Modulation transfer function (MTF)
  • Flange focal length (FFL)

Fitted with a motorised V-Block accessory for testing centration errors <3 arcseconds in both transmission and reflection

Fisba Interferometer

  • Phase-measuring 100mm aperture interferometer system
  • Non-contact high speed measurement of surface flatness and irregularity
  • Objective and precise measurement of transmitted wavefront error
  • Measurement accuracy of Lambda/20

Trioptics Prism Master

  • High speed electronic autocollimator with ultra-precise motorized goniometer
  • Completely objective high accuracy position measurement without operator input
  • Fully automatic angular measurements on prisms, beamsplitter cubes and polygons
  • Wedge measurement in optical windows
  • Accuracy of ±3 arc seconds (±0.00083°)
  • Comprehensive measurement and analysis software allows customized measurement procedures to be created and saved

In addition to our certification, our team of metrology technicians are trained in interpreting ISO10110 technical drawings for optical parts ensuring your specification will be followed exactly during testing. We also test to BS4301-1991, MIL-C-14806A and MIL-G-174B standards.



What's new

Contact Knight Optical

What's new