ODMR combines the spin-sensitive magnetic resonance technique with optical spectroscopy to very sensitively detect triplet excitons in SWCNTs. The ODMR signals not only confirm the existence of the triplet excitons but also reveal their specific properties, such as the specific strength of the spin-spin interactions (through the zero-field splitting) and the symmetry and lifetime of the triplet excitons. Moreover, after functionalization of the SWCNTs through sp3-defects, triplet states can be trapped in the defect sites and reveal very peculiar behavior.
