Second-order susceptibilities of ZnO nanorods from forward second-harmonic scattering

Abstract

Articles you may be interested inEnhancement in the structure quality of ZnO nanorods by diluted Co dopants: Analyses via optical second harmonic generation J. Appl. Phys. 117, 084315 (2015); 10.1063/1.4913724 Near-resonant second-order nonlinear susceptibility in c-axis oriented ZnO nanorods Appl. Phys. Lett. 105, 071906 (2014); 10.1063/1.4893599Efficient second harmonic generation in ZnO nanorod arrays with broadband ultrashort pulses A forward second-harmonic scattering method for determining the second-order susceptibility coefficients of ZnO nanorods on the order of 100 nm in diameter is presented. The long coherence length and strong intensity of the forward second-harmonic signal allow for a simple theoretical model to match the experimental measurements; this results in getting accurate values for the second-order susceptibility tensors. Different signs of d 31 and d 33 are confirmed. The results also show that Kleinman's symmetry is destroyed at a near-resonant second-harmonic wavelength of 405 nm for the ZnO nanorods.

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

“…The absolute value of d 33 is 15.5 pm/V. The sign of d 33 ∕d 31 is negative, which is similar to that of single wurtzite ZnO nanowires [28,32] . The second-order susceptibilities of bulk CdS crystal measured by Miller et [33,34] .…”

“…By applying the vacuum-substrate-nanowire-vacuum four layers model [28] , the transmitted SH fields can be written as…”

“…Compared to the forward SH emission, the back-irradiated SH emission has a much shorter coherence length and a much lower intensity, which will reduce the quality of the SH signals and the measurement accuracy. In this work, we utilize a forward SH scattering method [28,29] , which is ideal for characterizing nanostructures with similar sizes to the wavelengths involved, to characterize the second-order susceptibility tensors of single CdS nanowires. In addition, it has been reported that the second-order nonlinear optical response of a nanowire can be significantly influenced by the resonant excitation (i.e., the SH photon energy is above the bandgap of the semiconductor nanowire) [30,31] .…”

Near-resonant second-order nonlinear susceptibility in c-axis oriented ZnO nanorods

“…9,12,14,15 However, Kleinman's symmetry would be destroyed when the SHG wavelength is close to the bandgap of ZnO, which results in an enhancement of the d 131 component. 16,17 Thus, the determination of the d 131 near resonances would be important for the researchers to character and optimize the SHG efficiencies. Among ZnO nanostructures, the d 131 value of the c-axis oriented ZnO nanorods can be conveniently determined just with the normal incident pumping laser, which makes it more suitable for SHG study and applications in the nearresonant region.…”

“…Since the thickness is much larger than the coherent length of ZnO, the serious phase-mismatch in the ZnO single crystal results in a much weaker SHG. 16 The SHG signal intensity from the ZnO samples can be expressed as 13…”