abstract |
Methods for making a nonlinear optical device and related devices are disclosed. The method includes creating an ordered dispersion of charged particles in a surrounding medium. The charged particles and the surrounding medium are chosen such that they initially have identical refractive indices. In accordance with one aspect of the invention, cadmium sulfide inclusions are added to at least one of (a) the particles or (b) the medium. The cadmium sulfide inclusions have a highly nonlinear refractive index. The inclusions are optically nonlinear and upon high intensity radiation the refractive index of the particles change. This change in the refractive index occurs on the order of nanoseconds. In accordance with another aspect of the invention, a nonfluorescent dye is incorporated into at least one of (a) the particles or (b) the medium. The dye is photoabsorptive. Upon being impinged with high intensity radiation, the dye absorbs photons and heats the surrounding particles. This temperature increase causes a change in the refractive indices of the particles or medium. When the particle or medium refractive index is altered from that of the medium or particle the array diffracts light and prevents transmission of a specific wavelength. In accordance with yet another aspect of the invention, photorefractive materials such as lithium niobate or barium titanate substances can be used to induce the required optical nonlinearity. Related devices are also disclosed which exhibit high speed optical switching properties. The device may be employed advantageously in an optical computer or optical limiter. |