An optical information recording medium includes a substrate 1 and two
information layers (2, 4) formed on the substrate. The information layer
is formed of a thin film showing a change that can be detected optically
by irradiation of a light beam 7. A separating layer 3 that is
transparent to a wavelength of the light beam 7 is formed between the
information layers 2 and 4. Each information layer (2, 4) includes a
sector area having sector address portions (9, 13) and data areas (8, 12)
for recording information signals, the sector address portion and the
data area being divided in the circumferential direction, and a
management area (10, 14) for recording identification information about
the amount of dislocation between the sector address portions 9 and 14 in
the circumferential direction. Thus, the identification information about
the amount of dislocation can be recorded, so that demodulation errors
during reproduction can be reduced by switching amplification gain or
slice level during reproduction according to the identification
information. Also, stable data recording can be achieved by switching
recording power according to a gate signal.