Reflective mode conversions between extensional and flexural waves by ultrathin oblique anisotropic tri-component resonators

In this letter, we report a theoretical study for the conversions between extensional and flexural modes for Lame waves. The incident extensional waves can be completely converted into reflected flexural waves, or vice versa. The used structure is oblique anisotropic tri-component resonators with locally dipolar resonators. Without special optimization designs, the thickness of conversion device is much smaller than the working wavelengths (1/150 and 1/15 for the extensional and flexural waves, respectively). Our proposed design is more feasible for low-frequency application scenarios.