Imaging an off-plane shear wave source with two-dimensional phononic-crystal lens Chen-Yu Chiang and Pi-Gang Luan Wave Engineering Laboratory, Department of Optics and Photonics, National Central University, Jhungli 320, Taiwan Abstract A two dimensional flat phononic crystal (PC) lens for focusing off-plane shear waves is proposed. The lens consists of a triangular lattice hole-array, embedded in solid matrix. Self-collimation effect is employed to guide the shear waves propagating through the lens along specific directions. Dirichlet-to-Neumann Maps (DtN) method is employed to calculate the band structure of the PC, which can avoid the problems of bad convergence and fake bands automatically in the void- solid PC structure. When the lens is illuminated by the off-plane shear waves emanating from a point source, a subwavelength image appears in the far-field zone. The imaging characteristics are investigated by calculating the displacement fields explicitly using the multiple-scattering method, and the results are in good agreement with the ray-trace predictions. Our results may provide insights for designing new phononic devices. arXiv:1001.0246v1 [cond-mat.other] 2 Jan 2010 PACS numbers: 41.20.Jb, 43.20.El 1