Low-loss c-axis oriented Zn0.72Mg0.28O nonlinear planar optical waveguides on silicon

A material platform of highly c-axis oriented Zn 1-x Mg x O thin films is developed for nonlinear planar waveguides and electro-optic modulators on Si. Mg content in the film greatly influences the quality of film growth. The second harmonic generation measurement and Maker-fringe analysis reveal that the second-order nonlinear susceptibility tensor element χ 33 of the annealed Zn 0.72 Mg 0.28 O is approximately 4.2 times larger than that of ZnO. The propagation loss of 633 nm wavelength light in the annealed air/Zn 0.72 Mg 0.28 O/SiO 2 slab waveguide is 0.68 ± 0.09 dB/cm and 0.48 ± 0.03 dB/cm for the TE0 and TM0 modes, respectively. These results suggest the great potential of the c-axis oriented Zn 0.72 Mg 0.28 O nonlinear planar waveguides for applications in on-chip optical interconnects.