摘要:
An information recording method enables the precise formation of a recording mark on a recording layer having a high light transmittance such as an L1 layer of a double-layered optical recording medium. The information recording method uses the following recording strategy. A laser beam is pulse-modulated so as to create a pulse series including a write pulse of a recording power and a cooling pulse of a base power. Data to be recorded is modulated to have a length of a recording mark along a track of the recording layer. At the same time, the length of the recording mark is made to correspond to an integral multiple nT of T where T is one clock cycle. An nT recording mark corresponding to nT is recorded by using the same number of write pulses and cooling pulses when n is 4 or larger. Moreover, an average width AveTc for a single cooling pulse width Tc is set to satisfy: 1.0
摘要:
An information recording method enables the precise formation of a recording mark on a recording layer having a high light transmittance such as an L1 layer of a double-layered optical recording medium. The information recording method uses the following recording strategy. A laser beam is pulse-modulated so as to create a pulse series including a write pulse of a recording power and a cooling pulse of a base power. Data to be recorded is modulated to have a length of a recording mark along a track of the recording layer. At the same time, the length of the recording mark is made to correspond to an integral multiple nT of T where T is one clock cycle. An nT recording mark corresponding to nT is recorded by using the same number of write pulses and cooling pulses when n is 4 or larger. Moreover, an average width AveTc for a single cooling pulse width Tc is set to satisfy: 1.0
摘要:
A method of recording data on a double-layer optical recording medium having a recording layer with high light transmittance is provided. A laser beam is modulated to emit a pulse series of laser including a write pulse of a write power and a cooling pulse of a bottom power, so as to encode and write data to be recorded as recording marks of a length nT along a track of the recording layer, where n is an integer and T is one clock cycle. An nT recording mark is formed using (n−1) write pulse(s), and when forming a recording mark of 4 T or longer, a cooling pulse with a pulse width of 0.8 T to 2 T is inserted before the last write pulse. Recording marks are thereby accurately formed without heat interference between consecutive recording marks and cross erase between recording marks of adjacent tracks.
摘要:
A method of recording data on a double-layer optical recording medium having a recording layer with high light transmittance is provided. A laser beam is modulated to emit a pulse series of laser including a write pulse of a write power and a cooling pulse of a bottom power, so as to encode and write data to be recorded as recording marks of a length nT along a track of the recording layer, where n is an integer and T is one clock cycle. An nT recording mark is formed using (n-1) write pulse(s), and when forming a recording mark of 4 T or longer, a cooling pulse with a pulse width of 0.8 T to 2 T is inserted before the last write pulse. Recording marks are thereby accurately formed without heat interference between consecutive recording marks and cross erase between recording marks of adjacent tracks.
摘要:
A holographic recording medium in which a thick holographic recording layer is formed without the use of multilayering and without accompanying thickness unevenness, scattering, and nonuniformity of dynamic range, and a method for manufacturing the same. The holographic recording medium 10 is configured by sandwiching a hybrid material layer 14 and a photopolymer layer 16 between first and second substrates 12 and 18. The hybrid material layer 14 contains an inorganic glass and a photopolymer as main ingredients. The photopolymer layer 16 subjected to heat or ultraviolet curing is provided on the dried hybrid material layer 14 such that the combined thickness of this hybrid material layer 14 and the photopolymer layer 16 is uniform. The second substrate 18 is bonded and fixed to this photopolymer layer 16 serving as a bonding layer.
摘要:
A method and apparatus for performing reproduction position servo-control without reducing the recording capacity of a holographic recording medium. Upon the reproduction of a holographic recording medium 18, part of a reproduction beam serving as a servo beam is projected onto a recording layer 18A of the holographic recording medium 18 from the side opposite to the side of the reproduction beam (a reference beam) along the same optical axis as that of the reproduction beam, and the diffraction beam thereof is detected by a photodetector 26C through a polarizing beam splitter 26B.
摘要:
A holographic recording method and apparatus capable of performing phase code multiplex recording without employing a phase spatial light modulator. The holographic recording apparatus 10 performs phase spatial modulation of a reference beam to be projected onto a holographic recording medium by means of a phase code mask 26 in which phase code patterns are recorded in advance as a hologram and which is employed in place of a phase spatial light modulator in a reference optical system 20.
摘要:
In a holographic recording medium, noise is prevented from being generated by servo light in a recording layer without scarifying recording regions. A holographic recording medium 12 has a servo layer 16 formed on a recording layer 14 on a substrate 13 via a spacer layer 15. The servo layer 16 reflects the servo light and has one of wavelength selectivity and incident angle selectivity each of which allows object light and reference light to pass through.
摘要:
A holographic recording medium which has parallelism of high precision and causes little substrate deformation ascribable to contraction of its recording areas when recording interference fringes, and a method for manufacturing the same. The holographic recording medium has a holographic recording material layer between a first transparent substrate and a second transparent substrate. This holographic recording material layer is formed integrally with a spacer which is composed of a large number of spherical beads arranged so as to surround recording areas for interference fringes to be recorded on.
摘要:
There are provided a holographic recording method, a holographic recorder, a holographic recording/reproducing method, a holographic recorder/reproducer and a holographic recording medium as follows. Information is angle-multiplex-recorded as a hologram by a first format in which one of a signal light and a reference light branched from a laser light source intersects the other at a specified incident angle in a recording layer and the incident angle is altered at a specified angular pitch or a second format having a higher angle selectivity. When information is recorded in the second format having a higher angle selectivity, the incident angle can be adjusted to include such an incident angle that satisfies Bragg's conditions at the time of recording in the first format and compatibility of reproduction can be ensured between media having different angle selectivity.