A rewriteable diffraction grating contains first nanoparticles and second nanoparticles. Each first nanoparticle is configured and arranged to generate one or more charge carriers in response to a write beam. Each second nanoparticle is configured and arranged to substantially alter its response to light from a read beam upon receiving one or more charge carriers from the first nanoparticles. The second nanoparticles are disposed in proximity to the first nanoparticles to permit charge carriers generated by the first nanoparticles to interact with the second nanoparticles.