PHASE-CHANGE WRITING IN A GESBTE FILM WITH SCANNING NEAR-FIELD OPTICAL MICROSCOPE

Scanning near-field optical microscopy (SNOM) was applied to phase-cha nge (PC) mark writing to investigate the potential of ultrahigh densit y data storage, GeSbTe, one of the typical PC media, was used as a rec ording layer. Using a laser diode (LD) with a wavelength of 785 nm as light source, crystalline marks with a minimum size of similar to 80 n m in diameter were successfully written in the amorphous GeSbTe film w ith pulse conditions of 5 ms and 0.5 ms and 8.4 mW inside the probe. T he detected power in observation of the marks was 10(2)-10(3) times as high as that in magneto-optical (MO) observation.