Superresolution Enhancement With Active Convolved Illumination And Correlations

The promise of high-resolution imaging beyond the diffraction limit has been a core motivation for research in the fields of metamaterials and plasmonics. However, the problems with material losses have quelled some of the enthusiasm which once existed. Here, we review our recent approach relying on imaging theory and correlations to push the limits of superresolution imaging in the presence of losses and noise. Starting with plasmon injection scheme for compensating losses, we subsequently extended the same principle to a broad range of near-field and far-field imaging systems involving both coherent and incoherent light, and hence termed this approach more encompassing "active convolved illumination" (ACI). In ACI a relatively narrow range of spatial frequencies are amplified at a time. Since the total power in the active image does not change significantly, the spectral SNR is significantly improved in the region of amplification. This improves the overall resolution of the images. We also present potential extension of ACI into different research domains including atmospheric imaging, time-domain spectroscopy, and quantum computing.