22 Dec 2016 Fresnel lenses consist of a flat surface with interspaced, concentric steps whereby each step corresponds to the surface of a conventional lens. Each step thereby acts as a refractive surface, much like a prism. This gives the Fresnel lens a common focal length equivalent to a traditional lens, but with a fraction of the thickness. Additionally, because the lens is so thin little light is lost by absorption. Although the image quality is generally poor, Fresnel lenses can be desirable for use in condenser and lighting systems to collimate and collect light. Fresnel lenses can be used as magnifiers, but this is not recommended unless the thin profile and light weight is absolutely necessary.
Knight Optical offers a range of custom Fresnel lenses made from PMMA Acrylic or glass made to your custom specification. Our custom PMMA Fresnel lenses are available in two grades. Our custom “standard range” start from 5mm f.l x 5mm diameter aperture up to 254mm f.l x 152mm dia aperture. Our precision custom range has tight tolerances with improved surface quality and come in large aperture sizes. Our precision range of Fresnel lenses start at 22.2mm f.l x 44.4mm aperture up to 600mm f.l x 600mm dia aperture. Custom precision grade Fresnel PMMA lenses are ideal for simulators and projection systems. We can also supply a range of custom cylindrical Fresnel lenses. These custom Fresnel lenses have a range of square and circular apertures and can easily be cut to smaller sizes or edged to custom diameters. We provide a range of uncoated custom Fresnel lenses however we can also supply antireflective coated Fresnel lenses at short notice. We also offer high quality custom glass Fresnel lenses where required.
Every component is individually tested by our highly skilled technicians in our state of the art metrology lab to ensure all components meet our high quality standards.
Our custom Fresnel lens capability sheet can be found here: Capabilities - Fresnel Lenses
|
Material:
|
PMMA Acrylic
|
|
Center thickness:
|
+/- 0.2mm
|
|
Clear aperture:
|
Nominal
|
|
Focal length: Standard range Precision range
|
± 5% ± 2%
|
|
Design condition:
|
Parallel light on grooved side
|
For more information please click here | 
