POLYMERIC COMPOSITIONS

摘要

A switching medium which is based upon an SiO polymeric chain (optionally cross-linked) substituted with organic groups collectively adapted to: (i) confer photonic activity on the polymer to cause a change of refractive index in response to an optical control signal; (ii) to adjust the refractive index of the polymer to match a substrate; and (iii) to reduce the reactivity of the polymer, wherein 1 % to 75 % of said organic groups are photonically active groups selected from: Ar-CH=CH-L-, Ar-CH=N-Ar-L-, Ar-N=CH-Ar-L-, Ar-N=N-Ar-L-, wherein Ar is an aromatic or hetero-aromatic and L is a linkage attached to a silicon atom. There are at least two different blocking groups selected so as to confer the desired refractive index. These media are switched between two refractive indices by actuating radiation and they are used to control the passage of radiation in optical waveguides.