An investigation was made of the possibilities of optical recording on bubble-forming metal/thermodegradeable-plastic bilayers incorporated in front-surface trilayer devices. Two distinct types of trilayer device were chosen for study. It was found that a device consisting of a 14 nm-thick metal layer, a 200 nm-thick thermodegradeable-plastic dielectric layer and a 100 nm-thick aluminum layer had promising properties. That is, a power of only 6.5 mW focussed into a 0.8 μm spot at 442 nm (the helium-cadmium laser line) was required to write a 5 MHz-pattern with 50% duty cycle. This pattern is observed with high contrast at 633 nm (the helium-near laser line), where the initial reflectivity is 0.9, and it provides signal to noise in a 30 kHz bandwidth of 45 dB. The trilayer device is also calculated to have the same writing sensitivity at 830 nm (the gallium arsenide laser line).
G. A. N. Connell,
R. I. Johnson,
"Trilayer Bubble-Forming Optical Recording Media", Proc. SPIE 0329, Optical Disk Technology, (27 May 1982); doi: 10.1117/12.933389; https://doi.org/10.1117/12.933389