Diffusers
Diffusers alter the divergence of incident light and are available in five standard types, which can all be supplied to custom shapes and bespoke sizes to meet your specific requirement.
In addition to design and entertainment applications diffusers are used in tradition imaging techniques and for the control of illumination for optical sensing and military instrumentation and imaging applications.
Our range of custom diffusers includes ground glass , plastic screens, Anti-Newton
and flashed opal and holographic diffusers. Each of these custom diffuser types diffuses incident light in a different way and are used in different applications, with anti-Newton glass primarily used in photography and opal diffusers often used in lighting design.
Custom Anti-Newton Glass: When two flat optical surfaces are in close proximity interference effects associated with residual Fresnel reflection can be seen, these are a special case of newton’s rings. Anti-Newton glass sheets are lightly etched to deform the surface enough to prevent this but with minimal effect on image quality. Anti-Newton material is often used in scanners and film enlargers for scanning photography negatives etc. without seeing the interference rings (Newton`s rings). Knight Optical stock large sheets of Anti-Newton glass in 3mm thickness, enabling us to offer custom sized Anti-Newton glass diffusers. Custom Anti-Newton Diffusers can be made to any bespoke shape, diameter, square or rectangle either with cut and chamfered edges or fine ground to meet your specific custom Anti-Newton glass diffuser requirement.
Custom Ground Glass Diffusers: Ground glass diffusers scatter light at angles up to about 10°. Custom ground diffusers are utilised in two main applications. Firstly for focussing and secondly to enhance illumination uniformly in lighting systems. Knight Optical offers two types of custom ground glass diffuser . Custom borosilicate ground glass diffusers, which cover a range of 310 – 2700nm and custom UV grade fused silica ground glass diffusers which work down to 170nm in the UV. Custom borosilicate ground glass diffusers can be offered in large sheets up to 1150x850mm and in special cases 2300x1700mm and in thicknesses from 0.7mm to 15mm thk. These can be made to any bespoke shape, diameter, square or rectangle either with cut and chamfered edges or fine ground to meet your specific custom ground glass diffuser requirement. The ground surface can be custom ground diffused to your specific grade although 40 micron grit size covers most applications. Custom UV grade fused silica
ground glass diffusers can be offered in large sizes up to 300mm dia and in any thickness. These can be made to any bespoke shape, diameter, square or rectangle either with cut and chamfered edges or fine ground to meet your specific custom UV grade diffuser requirement. The ground surface can be custom stock UV grade diffuser to your specific grade although 40 micron grit size covers most applications.
If your UV wavelength application goes no further into the UV than 270nm quartz glass can be used where sheets of 1000x1000mm are available. Ground glass diffusers diffuse light less thoroughly than our opal diffusers but do so with less scattering losses.
Custom White Flashed Opal Diffusers: Opal diffusers offer a more thorough diffusion with a distribution close to lambertian, with the brightness of the diffuser being independent of the viewing angle. Such wide scattering angles will inevitably reduce brightness, however opal diffusers can be very useful in light boxes and other illumination systems. Custom flashed opal diffusers can be supplied in large sheets of 1400x1600m, and special larger sizes on request. The large sheets are available to make any bespoke shape, diameter, square or rectangle either with cut and chamfered edges or fine ground to meet your specific custom white flashed opal diffuser requirement. Pot opal is also available which is just the opal layer. Both white flashed opal (opalika) and pot opal can be polished down to achieve a thinner opal layer. The standard thickness on white flashed opal being 0.45mm thk.