Magneto-optical memory element

Abstract

Abstract A magneto-optical memory element including: grooves, formed on at least one surface of a transparent substrate, for guiding a light beam; a magneto-optical recording layer formed on the surface of said transparent substrate on which the grooves are formed, wherein a width of each groove and a width of each land formed between the grooves are substantially equal, information is recorded on and reproduced from tracks on the grooves and the lands, and a groove depth d (track depth) is arranged such that 0.13×λ/n≦d≦ 0.18× λ/n, where λ is a wavelength of the light beam and n is a refraction index of the transparent substrate. Assuming that a diameter of the light beam at a portion where a light intensity of the light beam becomes 1/e 2 of a light intensity of the center of the light beam is L, a track pitch p is arranged such that 0.6≦L/p≦1.2. Therefore, even when the track density is increased, i.e., the width of the groove portion and the width of the land portion are reduced, a satisfactory signal quality with low level of crosstalk is obtained. Accordingly, such a magneto-optical disk achieves a high recording density.

Inventors

• 👤 Michinobu Mieda
• 👤 Hiroyuki Katayama
• 👤 Akira Takahashi
• 👤 Kenji Ohta

Bibliographic Details