| 摘要 |
PURPOSE:To reduce pit diameter and rims and contrive a higher recording density, by a system wherein a substance having a lower boiling point, a lower subliming temperature or a lower temperature for generating a gas through pyrolysis in a recording film is instantaneously changed from a solid stage to a gaseous state, and the force of rapid volume expansion attendant on the change is utilized to blow off a substance having a higher boiling or subliming point. CONSTITUTION:A recording film 12 of a recording medium 15 has a structure in which ultrafine particles of Te with a diameter of not more than 100Angstrom are dispersed in a C-H compound 27. The evaporating temperature of the C-H compound 7 is 150 deg.C, while the boiling point of Te is 989.8 deg.C. When the recording film 12 is irradiated with a semiconductor laser beam 24 with a wavelength of 830nm by condensing the beam of a diameter of about 1-2mum by a lens 25 and with such a power as to melt even the Te particles, mainly the Te particles 28 absorb the energy of the beam, to cause a temperature rise in the recording film in the irradiated region 29. At this moment, the C-H compound 27 in the recording film 12 is rapidly evaporated with the attendant volume expansion, whereby the Te particles 28 are blown off. By this system, the size of a rim formed can be reduced, as compared with that in a melting system wherein a pit is formed based only on a surface tension at the time of melting. |
