First-order quasi-phase-matched blue light generation in surface-poled   Ti:indiffused lithium niobate waveguides
  We demonstrate efficient first-order quasi-phase-matched second-harmonic generation in a surface periodically poled Ti:indiffused lithium niobate waveguide; 6 mW of continuous-wave blue radiation (wavelength = 412.6 nm) was produced showing the potential of surface domain inversion for efficient nonlinear waveguide interactions. 
Alessandro C. Busacca, Collin L. Sones, Robert W. Eason, and   Sakellaris Mailis
physics.optics