Synthesis of nonlinear optical polymers functionalized with 4‐amino‐4′‐cyanostilbene and ‐azobenzene dyes. Second harmonic generation in corona‐poled thin films

The synthesis and susceptibilities χ and χ to two series of polymethacrylates functionalized with 4‐dialkylamino‐4′‐cyanoazobenzene and 4‐dialkylamino‐4′‐cyanostilbene dyes are reported. The monomeric dyes were homo‐ and copolymerized with methyl methacrylate in various ratios, to produce polymers useful for nonlinear optical (NLO) applications. The second‐order nonlinear optical properties of corona‐poled aligned polymers were evaluated by second harmonic generation measurements. The χ results for the azo‐dye polymers are in the range of 25–324 · 10−9 esu, and for the stilbene‐dye polymers in the range of 42–57 · 10−9 esu, depending on the functionalisation degree of the copolymers. The poled films do not show a significant decay in the second harmonic signal after four months.