Stable electro-optical or photonic device with small optical loss, resistant to relaxation after orientation - has layer of oriented, cross-linked poly adduct of glycidyl ether or ester compound with non-linear optically active groups and organic di or poly cyanate.

: Nordmann, J.; Beckmann, S.; Etzbach, K.H.; Sens, R.; Bauer, M.; Krueger, H.; Bauer, J.; Guenzelmann, C.; Hartmann, H.; Walter, A.

Abstract
In electro-optical and photonic devices with a functional layer of oriented, cross-linked non-linear optical (NLO) polymer between 2 buffer layers, the polymer is a polyadduct (I) containing a NLO grouping, derived from (a) NLO active compound(s) (II) containing glycidyl ether or glycidyl ester groups reacting with cyanate groups and (b) organic di- or polycyanate(s) (III). USE - The devices are planar waveguides, the function of which can be changed by electric potential, used in non-linear optics and optical information technology, e.g. modulators, Mach-Zehnder modulators, tuneable and switchable couplers, (tuneable) wavelength filters and polarisation modifiers. ADVANTAGE - Relaxation and hence loss of NLO activity is a problem with most polymers that have the required high second order susceptibility, which makes them unsuitable for technical devices requiring long-term stability. Relaxation after orientation is avoided or inhibited in (I) and optical losses are small. Usually, rel axation is avoided up to temperatures > 100 deg. C and (I) are stable at temperatures > 200 deg. C. Very wide variation of the optical properties is possible.