Nano Scale Shaping and Focusing of Light in 2D Short-wavelength Platforms
The ability to shape and focus optical waves to dimensions smaller than their wavelength has intrigued the scientific community both for its physical challenges and its potential applications. Resonant elements, , have provided deep-subwavelength control at long wavelength in the form of Metamaterials, while at optical frequencies light could be focused to specific points by nano-antenna and Nanofocusing elements, breaking the so-called diffraction limit. Alternatively, achieving similar focusing dimensions by scaling the diffraction limit rather than breaking it allows flexible and dynamic control over the type and shape of the focusing without specifically patterning the medium, hence can provide super-resolution capabilities for bio-imaging, nanolithography and spectroscopy. We use the high refractive index of Silicon to scale the diffraction limit by many-fold compression of the wavelength thereby achieving resolution at the order of 10-s of nanometers at visible light. - Comparable to that of single-molecule microscopy techniques. Utilizing this scaled diffraction limit, we present phase-resolved near-field observations of propagating-waves bright and dark focusing below 70 nm at 671nm illumination (λ/10), and direct observation of short-wavelength Super-Oscillations in planar 2D Hybrid Silicon-plasmon waveguides.