RESUMO
Recording and retrieving small marks far beyond the optical diffraction limit in a high-speed rotating phase-change optical disk have been investigated by use of a thermoreversible organic thin film as a superresolution mask layer. The organic thin film exhibited significant thermoreversibility and rapid response on laser irradiation. Recorded marks as small as 120 nm in length could be detected by a dynamic disk tester with a laser wavelength of 635 nm and a numerical aperture of 0.6.
RESUMO
We propose a novel, to our knowledge, silicon planar-apertured probe array as an optical head for high-density near-field optical storage. In comparison with a conventional fiber probe employed for near-field optical storage the apertured probe array has a higher readout data-transmission rate and better mechanical durability. A probe array with an aperture size of 100 nm was fabricated by use of photolithography and wet etching of a silicon wafer. Subwavelength-readout capability was demonstrated by use of one aperture of the probe array. Furthermore, we achieved a 16 times increase in the light-transmission efficiency of the probe array by installing glass-sphere microlenses on each aperture. The increase was confirmed by measurement of the near-field optical intensity.
