To provide a polymer usable in an optical device such as an electronic cold light radiation device.

The invention relates to a method for making a linear polymer containing a first repeat unit having general formula (1) which may be substituted or unsubstituted. Where, in the formula, x is 0 or 1; each Ar is the same or different and independently is a substituted or unsubstituted aryl or heteroaryl group and R and R' each is hydrogen or a substituent group and a second repeat unit that is the same or different from the first repeat unit and comprises a substituted or unsubstituted, aryl or heteroaryl group. The polymer is made by Suzuki polymerization wherein the monomer from which a repeat unit (1) is derived comprises one or two reactive boron groups.