A new family of functionalized second-order nonlinear optical polyimides has been developed. The key step in synthesizing these polymers was the syntheses of diamino NLO chromophores, which was accomplished by utilizing the Mitsunobu reaction. The polyimides were obtained from the corresponding poly(amic acids) which exhibited good solubility in aprotic polar solvents, permitting device processing. High glass transition temperatures were obtained in these polyimides, rendering a high stability in dipole orientation at elevated temperatures. The second harmonic generation signals exhibited no decay at room temperature or at 90-degrees-C. A long term stabilityf at 170-180-degrees-C was observed.