Optische Elemente aus Kunststoff

Plastics optical element consists of a polycyanurate resin(I). (I) is obtd. from polycyanate(s) (II) and/or a dicyanate of a perhalogenated dihydroxyalkane. (I) esp. is derived from a bisphenol A dicyanate and may be a co-reaction prod. of (II) with phenols, aromatic glycidyl ethers or glycidyl anilines. Esp. (I) contains 1-60 mole-% phenol, 1-99 mole-% glycidyl ether, 1-99 mole-% glycidylaniline or a mixt. of these w.r.t. (II). (I) has a Tg of 100-250, esp. 180-250deg.C. The elements have a refractive index of 1.45-1.70, esp. 1.55-1.65 at 633 nm and optical attenuation of 0.1-1.0 dB/cm at 1.3 or 1.55 microns. They are obtd. by spin coating a (I) soln or from the melt by moulding or embossing, followed by thermal curing opt. in presence of catalyst. USE - (I) is used for making optical elements, esp. waveguide structures, lenses, prisms, corrected lens systems, optical fibres and substrates for optical coatings and adhesive for optical components (all claimed), and is also useful for c oupling fibres and numerous other purposes. ADVANTAGE - (I) is easily processed, has variable refractive index, is thermally and thermomechanically stable and has little absorption at 1.3 and 1.55 microns. (I) also has good adhesion to various substrates.