diffrverts

Diffrverts are a proposed class of optical devices that aim to control diffraction in a reversible way. They seek to redistribute, concentrate, or invert the spread produced by diffraction, yielding output fields different from ordinary diffracted patterns.

Origins: The term is used in speculative discussions of advanced diffractive optics and is not widely established as a practical technology. The core idea is to impose a tailored phase profile on a diffractive element so the diffracted field performs a chosen transformation.

Principles: A diffrvert leverages a metasurface or diffractive optical element with spatially varying optical path length. By solving an inverse diffraction problem, designers steer energy into selected directions, refocus spread energy, or compensate for diffraction introduced by a medium.

Realization: Implementations involve metasurfaces, stacked DOEs, or patterned subwavelength layers. Designs use numerical optimization and rigorous analysis to maximize efficiency for a target wavelength; broadband variants remain challenging.

Applications: Potential uses include imaging through scattering media, compact high-NA lenses, beam shaping in communications, and adaptive optics for microscopy.

Limitations: Practical challenges include wavelength sensitivity, limited angular ranges, fabrication tolerances, and partial efficiency. As a speculative concept, it has not yet yielded widely demonstrated devices.

See also: diffraction, diffractive optics, metasurfaces.