New write-once medium with NiOx film using blue laser

Both a new write-once medium with a sputtered NiOx film and a write-once optical disk using a blue laser has been fabricated. The optical constant of sputtered NiOx films for different ratios Of O-2/Ar was determined, and showed little dependence on sputtering ratios Of O-2/Ar and wavelength. The X-ray photoelectron spectra (XPS) data indicated those films have two major components, NiO and Ni2O3. Most NiOx films released oxygen gradually below 300 degrees C. Over 300 degrees C, there was an apparent transition due to the decomposition of the Ni2O3. At a writing power of 12 mW and a reading power of 0.5 mW under conditions of a numerical aperature (NA) of 0.65 and a wavelength of 405 nm, the carrier to noise ratio (CNR) was more than 47 dB and jitter was less than 13%. The recording principle depends primarily on the explosive pressure of the O-2 released due to laser heating of the NiOx film.