An optical modulator includes a first layer that is transparent or semitransparent over a range of optical wavelengths; a modulation layer made from nanoparticles embedded in a matrix; a first electrode and a second electrode that create an electrical field that passes through the modulation layer. A method for forming a nanoparticle modulator includes obtaining and preparing a substrate; forming sub-layers on the substrate; forming a nanoparticle modulator layer, where the nanoparticle modulator layer is an electrical insulator and has a thickness of less than the wavelength of light the nanoparticle QCSE modulator is designed to modulate.