Multif requency three-dimensional optical read-only memory disks using metallic island films: preliminary experiments.
Basic operation of new multifrequency three-dimensional (3-D) optical read-only memory (ROM) disks has been demonstrated experimentally. Several types of metallic island film exhibiting a selectiveresonance absorption in a visible-near infrared region are used as recording layers on the 3-D disks. The monochromatic light with a suitable wavelength near the resonance wavelength of each layer is used for the readout of information. We demonstrate that bar-code patterns recorded in silver and copper island layers can be read by using transmitted or reflected light. Furthermore, we also show that the 3-D disks with ≥3 recording layers can be realized.
Baba
K
K
Yamada
R
R
Nakao
S
S
Miyagi
M
M