Single-walled carbon nanotubes are covalently functionalized by conjugated polyacetylenes through their cyclization reactions with poly(1-phenyl-1-alkyne) (3) and poly (diphenylacetylene) derivatives (6) carrying azido functional groups at the ends of their alkyl pendants. The resultant polyene nanotube addends (7 and 8) are soluble in common solvents, emit intense visible lights and strongly attenuate the power of harsh laser pulses.