Ultrafast optical switching properties of single-wall carbon nanotube polymer composites at 1.55 μm

Using a pump–probe method with a 150 fs laser at the wavelength of 1.55 μm, we have experimentally demonstrated that single-walled carbon nanotubes (SWNT) have an exciton decay time of less than 1 ps and a high third-order polarizability, which is reasonably interpreted as due to their azimuthal symmetry. These experimental results reveal that a SWNT polymer composite may be a candidate material for high-quality subpicosecond all-optical switches.