Second-harmonic generation in He+-implanted gadolinium calcium oxoborate planar waveguides

What is believed to be the first investigation of second-harmonic generatio n (SHG) in Ca4GdO(BO3)(3) waveguides is reported. A planar waveguide was fo rmed by 2-MeV-helium implantation. We cut the sample to achieve type I nonc ritical phase matching of an 823-nm fundamental wave for fundamental light propagating along the y axis and polarized along the z crystallophysic axis of the crystal. SHG was achieved with a relatively low pumping power of a cw Ti:sapphire laser. The results indicate that the nonlinearity of the mat erial remains in the guiding region after ion implantation. (C) 1999 Optica l Society of America. OCIS codes: 160.4330, 230.7370, 230.7390, 190.4400, 1 30.3130, 130.3120.