: Two laser beams intersect in a photosensitive medium (solid, liquid, or gas).
: Localized heating that changes the medium's refractive index.
: The resulting interference pattern creates a spatial distribution of light intensity. This triggers physical changes in the material, such as:
(LIDGs) are temporary optical structures created when two or more coherent laser beams interfere within a material. Unlike permanent gratings etched into glass, these "transient" patterns exist only while the light is present, making them vital for real-time optical processing. How They Work