Title :
Fabrication of magnesium-oxide-induced lithium outdiffusion waveguides
Author :
Lau, Chi-Sang ; Wei, Pei-Kuen ; Su, Chi-Wu ; Wang, Way-Seen
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
A short-time high-temperature diffusion process for the fabrication of the lithium niobate (LiNbO/sub 3/) optical waveguide with a magnesium-oxide (MgO) strip-loaded structure is presented. The deposited MgO layer causes the lithium to diffuse out of the LiNbO/sub 3/ substrate. The secondary ion mass spectroscopy (SIMS) data of the fabricated waveguide show that the lithium diffuses out of the substrate and gets into the MgO cover layer, which results in an increase in the extraordinary refractive index of the substrate. In particular, it is found that the diffused atoms are piled up near the LiNbO/sub 3/ and MgO interface. Also, the electrooptic effect of the fabricated waveguide is better than that of the conventional titanium-indiffused waveguide. Moreover, single-mode and single-polarization waveguides can be easily obtained without any significant surface guiding or surface damage on the crystalline substrate.<>
Keywords :
diffusion in solids; integrated optics; lithium compounds; magnesium compounds; optical waveguides; optical workshop techniques; LiNbO/sub 3/; cover layer; deposited MgO layer; diffused atoms; electrooptic effect; extraordinary refractive index; outdiffusion waveguides; secondary ion mass spectroscopy; short-time high-temperature diffusion process; single-mode; single-polarization waveguides; strip-loaded structure; substrate; waveguide fabrication; Diffusion processes; Electrooptical waveguides; Lithium niobate; Optical device fabrication; Optical refraction; Optical surface waves; Optical variables control; Optical waveguides; Particle beam optics; Surface waves;
Journal_Title :
Photonics Technology Letters, IEEE
