Title :
Optical TE-TM mode conversion using SH-SAW in ZnO/Y-X LiNbO/sub 3/
Author :
Nakamura, Kentaro ; Kitazume, H. ; Kawamura, Yuriko
Author_Institution :
Dept. of Electr. & Commun. Eng., Tohoku Univ., Sendai, Japan
Abstract :
The phase velocity of the SH-SAW in ZnO/Y-X LiNbO3 structure has been theoretically analyzed. It has been found that the SH-type leaky-SAW turns into an SH-SAW with no attenuation when h/Λ (ZnO film thickness/SAW wavelength) is greater than 0.09. At h/Λ=0.1, the electromechanical coupling factor K2 of the SH-SAW is as high as 21.4%. The collinear interaction between the SH-SAW and the optical waves in the ZnO/Y-X LiNbO3 structure has also been theoretically analyzed. The result shows that both the photo-elastic and electro-optic effects contribute constructively to the acousto-optic interaction. The refractive index change caused by the SH-SAW at h/Λ=0.1, is large near the substrate surface compared with that caused by the Rayleigh wave. The calculated coupling length required to achieve a 100% TE-TM mode conversion using the SH-SAW is smaller than that using the Rayleigh wave.
Keywords :
Rayleigh waves; acoustic wave propagation; acousto-optical effects; lithium compounds; refractive index; surface acoustic waves; zinc compounds; H-type leaky-SAW; Rayleigh wave; ZnO film; ZnO-LiNbO3; ZnO/Y-X LiNbO3; acousto-optic interaction; collinear interaction; coupling length; electro-optic effects; electromechanical coupling factor; optical TE-TM mode conversion; optical waves; phase velocity; photo-elastic effects; refractive index; substrate surface; Optical attenuators; Optical films; Optical refraction; Optical surface waves; Optical variables control; Refractive index; Substrates; Surface acoustic waves; Surface waves; Zinc oxide;
Conference_Titel :
Ultrasonics Symposium, 1999. Proceedings. 1999 IEEE
Conference_Location :
Caesars Tahoe, NV
Print_ISBN :
0-7803-5722-1
DOI :
10.1109/ULTSYM.1999.849480
