Structure-dependent anisotropy of the photoinduced optical nonlinearity in calcium doped ZnO nanorods grown by low cost hydrothermal method for photonic device applications

Calcium doped zinc oxide nanorods on ZnO seed layers were grown by hydrothermal method. Photoinduced bicolour laser treatment was done on the samples and the effective second order nonlinear coefficient (d(eff)) has been measured. The morphology of the samples was investigated by the field emission scanning electron microscope (FESEM) images. The structural parameters acquired from X-ray diffraction (XRD) patterns have been correlated with the measured d(eff). The results have revealed that 15 mol% Ca doped ZnO nanorod showed maximum d(eff) because of the Lorentz local field established along the length of the nanorod. The aspect ratio and stress play a significant role in enhancement of d(eff). The nonlinearity has been correlated with the absorption cross sections. (C) 2015 Elsevier B.V. All rights reserved.