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Looking For a Custom Optical Solution? Enquire


optical diffusers, ground glass diffuser, anti-newton glassKnight Optical can provide different diffuser types to suit your application. These include:

  • Anti-Newton glass which has a lightly etched surface which deforms it enough to prevent interference when placed on another optically flat surface.
  • Ground glass diffusers, where Knight Optical offer UV fused silica (175nm to 2200nm dependent on the thickness of the substrate) and borosilicate (310nm to 2700nm) options with one side diffused to a certain level to control the scattering angle.
  • Flashed opal diffusers offer a near Lambertian distribution of light, where the brightness is independent of the viewing angle. Though this diffuser type has now been discontinued, Knight Optical still hold a vast stock of it and can produce custom components for our customers.
  • Optolite(TM) HSR plastic diffusers offer a more superior and uniform diffusion than the aforementioned ground glass diffusers.
  • Plastic screen diffusers are a light, more flexible and cost effective solution. These can be cut into more complex shapes to fit individual custom enquiries.

Below are our typical manufacturing capabilities:


5mm to 100mm+

Scratch/dig (polished surface)

< 60/40

Grade of diffusion*

< 1500µm grit

Knight Optical is renowned for its custom orders, so please contact our dedicated account managers for more information on how we can help you with your enquiry.

Additional Information

  • Anti-Newton glass is used to remove the phenomenon known as Newton’s rings. These form when two optically flat surfaces are in contact with each other, for example when scanning photography negatives, which can cause distortion to the final scanned image. Anti-Newton glass is lightly etched on one surface which deforms the surface enough to prevent these rings but have minimal effect on the image quality.
  • Flashed opal diffusers produce a near Lambertian distribution/scattering where the brightness of the scattered light is independent of the angle that the diffuser is observed at. The name Lambertian scattering is used as the intensity of radiation follows Lambert’s cosine law.
  • Ground glass diffusers produced more of a Gaussian distribution (or a normal distribution) of scattered light where the angle of distribution is dependent on the level of diffusion.


Knight Optical can offer coatings for your optical diffuser, however we do not offer this as a standard option, so please enquire for further information.

Quality Assurance

  • Using handheld measuring devices and our Starrett AV300 Knight Optical can ensure the dimensional measurements are within tolerance, including for more complex components.
  • Any flatness and irregularity requirements are tested on our Zygo Verifire XPZ interferometer.
  • The scattering profile can be measured on our Agilent Cary 7000 Spectrophotometer which can perform spectral scans at multiple angles of incidence. A graph depicting this profile can be provided.
  • All optics are 100% visually inspected before packaging, our staff are trained to ISO 10110 and MIL-0-13830A, and can check down to 10/5 scratch/dig which is especially critical in laser applications.

Typical Applications

  • Anti-Newton glass is most commonly used in scanners and film enlargers.
  • Ground glass diffusers can be used in lighting systems to uniformly enhance and focus the
  • Plastic sheet diffusers are often used for back screen projection, commercial electronics as well as consumer applications.

Our 2022/2023 Catalogue

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.
Click below to view our digital catalogue now.

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