Quasi-phase matched second harmonic generation in periodically poled Rb-doped KTiOPO4 ridge waveguide.

ABSTRACT

A 10.8 µm wide ridge waveguide was fabricated by diamond-blade dicing in an ion-exchanged periodically poled Rb-doped KTiOPO4 sample. The waveguide was used to generate blue second harmonic light at 468.8 nm in the TM00 mode through first order Type I quasi-phase matching, exploiting the large d33 coefficient of the crystal. It was evaluated using a cw TiSapphire laser, and 6.7 µW of blue light was generated with 5.8 mW of fundamental radiation at 933.8 nm coupled through the waveguide. The results presented here pave the way for efficient nonlinear processes in a waveguide format.