Spatial frequency characterisation of a far field superlens to facilitate general purpose imaging
Based on sub wavelength energy concentration and enhancement of evanescent fields, far field super lenses (FSLs) were proposed recently as a means to achieve super resolution imaging and thus improve the accuracy and resolution of optical microscopy. Comprised of a thin film plasmonic enhancement layer and a diffraction grating, the performance of FSLs depends greatly on the geometry and size of its constituent parts. In this paper, we aim to characterize the resolution capabilities of FSLs in a novel and meaningful way, while also exploring the effects of non ideal grating geometries due to fabrication limitations on imaging performance. We use finite element modelling to explore trapezoidal, inverse trapezoidal, circular, rounded rectangular, and rectangular grating profiles and present a transfer function that quantifies the performance of these grating profiles in terms of their transmission at different wavenumbers.
Photonics Europe