QUASI-3-DIMENSIONAL, N-BIT OPTICAL MEMORY-BASED ON THE ELLIPSOMETRIC PRINCIPLE - MODEL-CALCULATIONS

Model calculations on the ellipsometric memory are presented. The elli psometric memory is an n-bit optical memory whose information is extra cted by use of the ellipsometric principle. The memory cells of the de vice consist of thin-film multilayer structures, and the information o f each memory cell is contained in the optical properties of the thin films. Several thin-film multilayer structures were examined in order to find out how different choices of layer materials and other system parameters such as layer thicknesses and wavelength affect resolutions and limitations of the ellipsometric memory. Such calculations are al so useful for optimizing the readout resolution. It was found that it is possible to use memory cells having up to at least eight layers, wh ich would permit 8-bit words to be stored at each location. It was als o found that, in principle, several types of materials can be used as layer materials, and various aspects of different choices of materials are discussed.