Optical diskette recording method - recording and reproducing information using laser beam with wavelength up to 500 nanometres on magneto-optical recording medium

摘要

The optical recording method involves recording information on a recording layer of an optical diskette. The gap between tracks on the substrate of the diskette is between 0.4 and 0.9 microns. The laser beam for recording is passed through a lens with a numerical aperture of 0.55 to 0.70. The substrate of the diskette is made of plastic. A non-reflecting coating layer is applied to the substrate, and the recording layer is a magneto-optical layer. The diskette substrate contains pits forming the tracks for recording information. The diskette substrate can be made of glass, PMMA, or a polycarbonate. A laser frequency of 17.5 MHz and pulse width of 20 nS is typically used. The laser source can be an Argon laser. USE/ADVANTAGE - External memory for computer. Low bit error rate. Shorter wavelength recording beam can be used, allowing increased storage density. No tracking grooves required, decreasing noise, increasing signal intensity.