Europe, UK, Asia & RoW: [email protected] +44 (0)1622 859444 | USA & Canada: [email protected] +1 401-583-7846

BREXIT UPDATE: Knight Optical will continue to provide quality assured service for all your optical requirements both custom & stock. We will handle all requirements caused by the new regulations.


Looking For a Custom Optical Solution? Enquire

Borosilicate or Equivalent Windows

Stock and Custom optical windows for OEMsWe offer two grades of custom borosilicate or equivalent  windows “float grade borosilicate or equivalent windows” which are cut from standard float sheet material and “polished grade borosilicate or equivalent  windows” which are further polished to better flatness and surface quality.

These custom borosilicate or equivalaent windows listed here are made from Low Expansion Borosilicate or equivalent glass. Borosilicate or equivalent has excellent transmission over the visible and NIR wavelengths working from 310nm to 2700nm. The surface quality is not as high as the BK7 or equivalent versions.  Custom Low-expansion Borosilicate (LEGB) or equivalent  Windows are very useful as windows in many harsh applications because borosilicate glass has excellent chemical and thermal-shock resistance and has a maximum working temperature of 500°C so are excellent for use in high powered light source applications or an excellent choice for cold and hot mirror substrates.   Custom Borosilicate or equivalent windows can also be a good substrate for optical flats as it has low expansion properties and therefore maintains its flatness in different environmental conditions.

Knight Optical supply high quality custom borosilicate windows made to your exact specification. Every component is individually tested by our highly skilled technicians in our state of art metrology lab to ensure all components meet our high quality standards.

Contact our multilingual technical sales team and discover how Knight Optical’s high quality custom borosilicate windows and service can improve your instrumentation and supply chain experience.

Our 2021/2022 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.

view our catalogue