Readout characteristics in double storage layer magneto-optical disk memories

Wavelength dependences of readout characteristics in double storage layer magneto-optical disks (DMO disks) have been investigated theoretically. A DMO disk consists of one reflective layer, two protective layers and two storage layers (I) and (II) separated by an intermediate layer. Signals from the storage layers (I) and (II) can be detected separately with different wavelengths. The separation of the readout signals from the storage layers occurs as a result of the interference effects in the intermediate layer, and the readout conditions are closely related to the thickness of the intermediate layer and the storage layer (I). When the storage layers (I) and (II) are detected with the wavelengths of 7800 Å and 8300 Å, respectively, the optimum thicknesses of the storage layer (I) and the intermediate layer are 120 Å and 1.915 µm for the thickness of the storage layer (II) of 800 Å.