Beam focusing in reflections from flat subwavelength diffraction gratings

Diffractive optics based on modulated subwavelength-domain V-ridge gratings

We study the properties of reflection-type V-ridge gratings in the subwavelength domain and describe a method to realize diffractive optical elements by using such gratings as signal carriers. In particular, we utilize a coding scheme based on position modulation of a high-frequency V-ridge carrier grating. We design and demonstrate beam splitting elements using this coding scheme, electron-bea...

Spatial optical phase-modulating metadevice with subwavelength pixelation.

Dynamic control over optical wavefronts enables focusing, diffraction and redirection of light on demand, however, sub-wavelength resolution is required to avoid unwanted diffracted beams that are present in commercial spatial light modulators. Here we propose a realistic metadevice that dynamically controls the optical phase of reflected beams with sub-wavelength pixelation in one dimension. B...

Subwavelength beam focusing by multiple-metal slits surrounded by chirped dielectric surface gratings

Deep subwavelength beam propagation in extremely loss-anisotropic metamaterials

Metal–dielectric multilayer metamaterials with extreme loss-anisotropy, in which the longitudinal component of the permittivity tensor has an ultra-large imaginary part, are proposed and designed. Diffraction-free deep subwavelength beam propagation and manipulation, due to the nearly flat iso-frequency contour, is demonstrated in such loss-anisotropic metamaterials. It is also shown that deep ...

Diffraction-limited performance of flat-substrate reflective imaging gratings patterned by DUV photolithography.

We report on the first demonstration of flat substrate imaging gratings fabricated by deep ultraviolet (DUV) photoreduction lithography, which uniquely offers sub-100-nm resolution and spatial coherence over centimeter scales. Reflective focusing gratings, designed according to holographic principle, were fabricated on 300-mm silicon wafers by immersion DUV lithography. Spatial coherence of the...