Patent ID: 6067189
Filing Date: 2000-05-23
Classification: G02B

Abstract:
A reflector having a composite reflectivity-enhancing layer as a reflecting surface layer on a reflector body where the reflector body is a metal, where the said composite layer has an outer layer facing the radiation to be reflected, the HI-layer, with a refractive index n.sub.2, and, between the reflector body and the outer layer, an LI-layer with a refractive index n.sub.1 which is smaller than n.sub.2 and the LI and HI layers are .lambda./4 layers, the HI layer is a sol-gel layer containing or consisting of a polymerization product of organically substituted alkoxy compounds and the optical layer thickness d.sub.opt,1 of the LI layer and d.sub.opt,2 of the HI layer are such that:d.sub.opt,l =d.sub.l.n.sub.l =l.sub.l..lambda./4.+-.20 nm, l=1 or 2where d.sub.1 represents the thickness of the LI layer in nm, d.sub.2 the thickness of the HI layer in nm, .lambda. the average wavelength in nm of the light striking the reflector surface and l.sub.1, l.sub.2 are uneven natural numbers, the thickness d.sub.1 of the LI layer and the thickness d.sub.2 of the HI layer are each between 30 and 350 nm, and are such that the thickness d.sub.1 and d.sub.2 measured at a particular site does not vary by more than .+-.5 percent from the average values of d.sub.1av and d.sub.2av over the whole of the composite layer.