Overcoming losses in superlenses with synthetic waves of complex frequency

TL;DR

This paper demonstrates a practical method using synthetic complex-frequency waves to counteract losses in superlenses, enabling deep-subwavelength imaging with potential for improved optical resolution.

Contribution

It introduces an experimental approach employing multi-frequency measurement to generate synthetic complex-frequency waves, overcoming loss limitations in superlenses.

Findings

Successful observation of deep-subwavelength superimaging patterns

Implementation of virtual gain via synthetic complex-frequency waves

Potential for enhanced imaging and sensing applications

Abstract

Superlenses made of plasmonic materials and metamaterials have been exploited to image features of sub-diffractional scale. However, their intrinsic losses impose a serious restriction on the imaging resolution, which is a long-standing problem that has hindered wide-spread applications of superlenses. Optical waves of complex frequency exhibiting a temporally attenuating behavior have been proposed to offset the intrinsic losses in superlenses via virtual gain, but the experimental realization has been missing due to the challenge involved in preparing the illumination with temporal decay. Here, by employing multi-frequency measurement, we successfully implement a synthetic optical wave of complex frequency to experimentally observe deep-subwavelength superimaging patterns enabled by the virtual gain. Our work represents a practical approach to overcoming the intrinsic losses of plasmonic systems for imaging and sensing applications.