Conceptual

Flat Metamaterial Gradient-Index Lenses for Millimetre-Wave Telescopes

A telescope architecture in which every optical element is a thin, flat metamaterial lens rather than a thick curved refractor. Each lens is a hot-pressed stack of photolithographic capacitive metal-mesh grids forming a flat gradient-index ('Wood') lens whose graded effective index focuses the beam, provides a built-in anti-reflection coating, and performs low-pass frequency filtering in a single component. The design combines optical ray-tracing with transmission-line modelling of the meshes; a three-lens prototype rivals conventional refractive telescopes while cutting weight over 80% and avoiding cryogenic coating-delamination problems.