Subdiffraction far-field imaging of luminescent single-walled carbon nanotubes

Far-field near-infrared fluorescence microscopy of single-walled carbon nanotubes (SWNTs) has been hampered by the diffraction limit to resolution. A new analysis method is presented that allows subwavelength (lambda/10) mapping of single-molecule chemical reaction sites on semiconducting SWNTs, enabling precise localization of excitonic luminescence regions along the nanotube axis through a nonperturbing, far-field optical measurement. This method is applied to reveal the subdiffraction lengths, curvatures, and defects of luminescent SWNTs in unprecedented detail.