Lighthole

Lighthole is a term that appears in speculative or fictional contexts to refer to an optical construct that provides a direct, highly efficient pathway for light to traverse an obstacle or medium. It is not a standard concept in mainstream optics or physics.

In theoretical discussions, a lighthole might be imagined as an engineered aperture, nano-scale channel, or surface defect that couples incident light into a guided mode with minimal loss, or as a metamaterial feature that routes electromagnetic energy along a designed trajectory. Such descriptions are hypothetical and used mainly in thought experiments or fiction; there is no widely accepted experimental realization under the name "lighthole."

Terminology note: the phrase "light hole" does exist in semiconductor physics as the name of the light-hole valence-band state. The single-word form "lighthole" is typically a misspelling or neologism, and should be distinguished from the established "light hole" concept.

In literature and media, lighthole can be used as a metaphor for a portal or conduit that transfers light or information quickly, sometimes serving as a plot device or speculative technology. Real-world research on light guidance relies on related concepts such as waveguides, photonic crystals, and nanostructured apertures, rather than a canonical entity known as a lighthole.