Carbon nanotube polycarbonate composites for ultrafast lasers

Carbon nanotube polycarbonate composites (PC) for ultrafast lasers is an ideal choice because of their high transparency and environmental, thermal, and chemical stabilities. Conjugated polymers, such as poly(phenylene vinylene) (PPV) derivatives, were proven effective to disperse bundles as well as individual single-walled carbon nanotubes (SWNTs) in common organic solvents such as chloroform or tetrahydrofuran (THF), due to π-π stacking of the aromatic rings of the polymer on the SWNT sidewalls through van der Waals interactions. The SWNTs were dispersed by ultrasonic treatment using regioregular poly(3-hexylthiophene-2.5-diyl) (P3HT) as dispersant in 1,2-dichlorobenzene (DCB). The saturable absorption prosperities of the composites were characterized by powder-dependent measurements at 1550 nm. Despite the high concentration of bundles, the processing technique ensures that these were sub-micrometer sized, key to avoiding scattering losses when operating at 1550 nm.