In situ poling and polymerization of multifunctional monomers for second harmonic generation

A novel method for the synthesis of second harmonic generating (SHG) materials is proposed and tested in which liquid, multifunctional monomers with dissolved dopants are poled and polymerized simultaneously. Instead of requiring multiple steps and hours or days to synthesize SHG materials, this technique is able to produce doped guest/host systems in a single step process which takes two minutes or less. In addition, the polymer that is produced is highly crosslinked and provides good thermal and temporal stability of the SHG. To increase the stability of the SHG signal the dopant can be attached to the crosslinked network further decreasing the mobility. Advantages of this process include its simplicity, speed, stability, and the ability to make SHG materials of any thickness by successively polymerizing layers. This work presents a detailed description of the new procedure as well as results for the effect of dopant concentration, the magnitude of the SHG, and the structure of the crosslinked polymer that serves as the dopant host. Also, a method of synthesizing functionalized Disperse Red 1 that can be incorporated as a side chain is presented. Results are presented for the order parameter and SHG stability at room temperature and 100°C.