“…Finally, they demonstrated the potential of these waveguides for the second harmonic generation of continuous-wave deep-UV laser light, exploiting the nonlinear optical properties of BBO crystal (Degl'Innocenti et al, 2008;Poberaj et al, 2009). Likewise, Jia and coworkers fabricated non-leaky planar waveguides on BBO by implanting medium doses (~10 14 cm -2 ) of 3 MeV Cu 2+ (Jia et al, 2008b) and Ni 2+ (Jia et al, 2008d) ions. …”