Nonlinear Optical Response in Single Alkaline Niobate Nanowires
We have synthesized and characterized three types of perovskite alkaline niobate nanowires: NaNbO3, KNbO3, and LiNbO3 (XNbO3). All three types of nanowires exhibit strong nonlinear response. Confocal imaging has been employed to quantitatively compare the efficiency of synthesized nanowires to generate second harmonic signal and to show that LiNbO3 nanowires exhibit the strongest nonlinear response. We also investigated the polarization response of the second harmonic generation (SHG) signal in all three types of alkaline nanowires for the two geometries tractable by our optical trapping setup. The SHG signal is highly influenced by the nanowire crystallinity and experimental geometry. We also demonstrate for the first time wave-guiding of SHG signal in all three types of alkaline niobate nanowires. By carefully examining nonlinear properties of (XNbO3) nanowires we suggest which type of wires are best suited for the given application.