Purified single-walled carbon nanotubes are dispersed in two different types of polymer matrices. In these stable dispersed systems, the interaction between the polymer matrix and the single-walled carbon nanotubes, optical power limiting effect, and two-photon absorption are investigated. Transmission electron micrographs show the rigid polymer backbone interacts with the single-walled carbon nanotubes and results in the formation of nanoribbons and nanobundles in the dispersions. Optical measurements show that the nanoribbons and nanobundles significantly improve the optical power limiting performance through increased nonlinear optical absorption. Detailed comparison of optical power limiting, two-photon absorption, and two-photon excited fluorescence emission is presented. Our experimental results show that the different polymer backbones have a considerable effect on the nonlinear optical properties of carbon nanotubes.