Abstract
When Lamb wave propagates in a crystal, the photo-elastic effect induces a refractive index change in a crystal and makes phase grating in a crystal. Therefore optical mode conversion occurs in the crystals which Lamb wave propagating. Using this phenomenon, it can be expect the Lamb wave type crystal substrate apply to the optical communication system. In this study, we had theoretically examined the optical mode conversion during refractive index period structure. The theoretical calculation result predicted a least power for the mode conversion at a model in various modes. Furthermore, when Lamb wave Λ =270μm and substrate thickness H=20μm in mode 1, Lamb wave power P_<100> to need for 100% optical mode conversion was 12.8mW. Which is very small power for the optical mode converter.
