Noncollinear second-harmonic generation in sub-micrometer-poled RbTiOPO(4)

We have generated noncollinear quasi-phase-matched second harmonic wave in an RbTiOPO(4) crystal that was poled using the high-voltage atomic force microscope (HV-AFM). To the best of our knowledge, this is the first systematic nonlinear frequency conversion study of samples produced by the HV-AFM method. The short poling period of 1.18 microm enabled us to observe second harmonic generation at very large angles with respect to the fundamental wave. The setup was used to optically explore the homogeneity of the poled area. The measurements are in a reasonable agreement with an analytic calculations.