We report on the synthesis and characterization of new crosslinked polymeric matrices, pertaining to the class of poly(amide-amine)s (PAAs), functionalized with highly performing nonlinear optical (NLO) heterocycle-based dyes as side-chain substituents. Linear, soluble, and highly crosslinked NLO-functionalized PAA networks can be easily prepared under mild conditions. The wide-ranging tunability of optical and mechanical properties of these matrices makes them a superior alternative to conventional high T-g thermoplastic polymers.