Resonant and nonresonant second-harmonic generation in a single cadmium sulfide nanowire

We experimentally investigate the resonant and nonresonant second-harmonic generation in a single cadmium sulfide (CdS) nanowire. The second-order susceptibility tensor is determined by analyzing the forward second-harmonic signals of the CdS nanowire. Our results show that (1) d(33)/d(31) = -2.5 at a nonresonant input wavelength of 1050 nm; (2) d(33)/d(31) = -1.9 at a resonant wavelength of 740 nm. The difference can be attributed to the polarization-dependent resonance.