Synthesis of frequency doubling polymeric materials, 2. Second‐order nonlinear optical properties of poled chromophore‐functionalized polystyrenes

The synthesis and frequency doubling properties of nonlinear optical chromophore functionalized polystyrene with 4‐nitro‐ or 4‐cyano‐4'‐hydroxyazobenzene, or 2‐[2‐(4‐hydroxyphenyl‐ethenyl)]‐3,5‐dinitrothiophene are reported. The polymers with longer spacer length of the side chain chromophore show higher X (2) values, because of a better alignment under poling conditions. Values as high as 23,8 · 10 −9 esu at 1064 nm can be achieved. With a stronger acceptor group (3,5‐dinitronthiophene) a value of 22 · 10 −9 esu was achieved for a chromophore content which was even 4 times smaller.