Fresnel Lenses
Fresnel Lens Arrays for PIR detectors
The Fresnel lens is a concentric stack of individual planar lenses each of which has a
different refractive index. This allows construction of a lens with much less thickness
than that of the standard spherical version. This is very important in infrared optics
because the material from which the lens is made has significant transmission loss. The
thinner the lens the lower the loss.
Applications