Abstract: A method for communicating between a surface containing a rare-earth oxide phosphor, which emits a second wavelength photon when excited by a first wavelength photon, and an article mounted on a device, wherein the method includes exciting the phosphor with a source that emits a first wavelength photon to produce a second wavelength photon response in the surface; and detecting the second wavelength photon with a means in communication with the article, wherein the article is capable of emitting a signal based upon receipt of the second wavelength photon.

Abstract: A method for inducing a visible light response in a material comprising combining an up-conversion phosphor, which emits visible light wavelengths when stimulated by non-coherent infrared wavelengths, with the material and activating the phosphor with a source that emits non-coherent infrared wavelengths to produce a visible-light response in the material.