High-power laser light source for near-field optics and its application tohigh-density optical data storage

A laser light source for high-resolution near-field optics applications wit h an output power exceeding 1 mW (10(4) times the power from previous sourc es) and small (300 nm square to less than 50 nm square) output beam size is demonstrated. The very-small-aperture laser (VSAL) tremendously expands th e range of applications possible with near-field optics and increases the s ignal-to-noise ratios and data rates obtained in existing applications. As an example, 250-nm-diam marks corresponding to 7.5 Gb/in.(2) storage densit y have been recorded and read back in reflection and transmission on a rewr itable phase-change disk at 24 Mb/s with a 250-nm-square aperture VSAL. VSA Ls potentially enable data storage densities of over 500 Gb/in.(2) (up to 1 00 times today's magnetic or optical storage densities). (C) 1999 American Institute of Physics. [S0003-6951(99)04734-8].