Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1591967 | Solid State Communications | 2014 | 6 Pages |
•A thin steel plate with quasi-periodic array of holes is fabricated to serve as a lens.•Subwavelength hotspots are observed in the post-evanescent field of the plate.•Imaging of a point source with good resolution at different positions is exhibited.
A thin steel plate with quasi-periodic array of holes is fabricated, which is demonstrated to be able to function as an acoustic lens. With either a plane wave or a point source in object space, hotspots with the smallest size up to one-fifth wavelength are observed in the post-evanescent field regime in image space. Imaging of a point source with good resolution at different positions is also exhibited. The singular field distributions originate from the interference of the diffractive beams specific to quasi-periodic structures, which generates distinct and plentiful diffractive patterns.