Holographic message encoded in simple plastic

https://phys.org/news/2024-03-holographic-message-encoded-simple-plastic.html

"adjusting thickness of the plate in just the right way, point by point, the superposition of all THz waves shined on plate produces exactly the desired image... calculate how thick the plate has to be at each point, so that it changes the terahertz wave in exactly the right way, to generate correct code... 3D print thickness profile plastic plate to store information holographically... shining THz of correct wavelength through this plastic plate eveals THZ ray image... cheaply store bitcoin, QR code"